TY - JOUR TI - Ash biomass forest: Alteration in the atributes of acid soils from santa catarina plateau and eucalyptus plants,Cinza de biomassa florestal: Alterações nos atributos de solos ácidos do planalto catarinense e em plantas de eucalipto AU - Da Silva, F.R. AU - Albuquerque, J.A. AU - Gatiboni, L.C. AU - Marangoni, J.M. T2 - Scientia Agraria DA - 2009/// PY - 2009/// VL - 10 IS - 6 SP - 475-482 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84883287197&partnerID=MN8TOARS ER - TY - JOUR TI - Grapes yield and chemistry composition in Cabernet Sauvignon grapevine with nitrogen fertilization,Produção e composição química da uva de videiras Cabernet Sauvignon submetidas à adubação nitrogenada AU - Brunetto, G. AU - Ceretta, C.A. AU - Kaminski, J. AU - Melo, G.W. AU - Girotto, E. AU - Trentin, E.E. AU - Lourenzi, C.R. AU - Vieira, R.C.B. AU - Gatiboni, L.C. T2 - Ciencia Rural DA - 2009/// PY - 2009/// VL - 39 IS - 7 SP - 2035-2041 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-70350044191&partnerID=MN8TOARS ER - TY - JOUR TI - Does resource complementarity or prevention of lodging contribute to the increased productivity of rice varietal mixtures in Yunnan, China? AU - Revilla-Molina, I.M. AU - Bastiaans, L. AU - Keulen, H. Van AU - Kropff, M.J. AU - Hui, F. AU - Castilla, N.P. AU - Mew, T.W. AU - Zhu, Y.Y. AU - Leung, H. T2 - Field Crops Research AB - We conducted an experiment in Gejiu, Yunnan Province of China during the wet season of 2002 to examine the importance of resource complementarity and prevention of lodging in the fast-spreading practice of growing rice varietal mixtures in China to suppress rice blast disease and its associated damage. The hybrid rice variety Shanyou 63 and the glutinous or sticky rice variety Huangkenuo were used to study intra- and inter-varietal competition in the rice intercropping system. The experiment was laid out as a randomized complete block design in four replications with pure stands and mixtures of both varieties at different total planting densities and mixing ratios. In half of the pure stand treatments of glutinous rice a metal frame was installed to prevent lodging. The results showed that resource complementarity between the two rice varieties, resulting from niche differentiation, was marginal and did not greatly enhance the productivity of the rice varietal mixtures. In contrast, prevention of lodging of glutinous rice was identified as an important additional advantage of growing these rice varieties in mixture. DA - 2009/4// PY - 2009/4// DO - 10.1016/j.fcr.2009.01.003 VL - 111 IS - 3 SP - 303-307 UR - http://dx.doi.org/10.1016/j.fcr.2009.01.003 KW - Blast suppression KW - Lodging KW - Relative yield total KW - Competition KW - Niche differentiation ER - TY - JOUR TI - Validating subcellular localization prediction tools with mycobacterial proteins T2 - BMC Bioinformatics AB - The computational prediction of mycobacterial proteins' subcellular localization is of key importance for proteome annotation and for the identification of new drug targets and vaccine candidates. Several subcellular localization classifiers have been developed over the past few years, which have comprised both general localization and feature-based classifiers. Here, we have validated the ability of different bioinformatics approaches, through the use of SignalP 2.0, TatP 1.0, LipoP 1.0, Phobius, PA-SUB 2.5, PSORTb v.2.0.4 and Gpos-PLoc, to predict secreted bacterial proteins. These computational tools were compared in terms of sensitivity, specificity and Matthew's correlation coefficient (MCC) using a set of mycobacterial proteins having less than 40% identity, none of which are included in the training data sets of the validated tools and whose subcellular localization have been experimentally confirmed. These proteins belong to the TBpred training data set, a computational tool specifically designed to predict mycobacterial proteins.A final validation set of 272 mycobacterial proteins was obtained from the initial set of 852 mycobacterial proteins. According to the results of the validation metrics, all tools presented specificity above 0.90, while dispersion sensitivity and MCC values were above 0.22. PA-SUB 2.5 presented the highest values; however, these results might be biased due to the methodology used by this tool. PSORTb v.2.0.4 left 56 proteins out of the classification, while Gpos-PLoc left just one protein out.Both subcellular localization approaches had high predictive specificity and high recognition of true negatives for the tested data set. Among those tools whose predictions are not based on homology searches against SWISS-PROT, Gpos-PLoc was the general localization tool with the best predictive performance, while SignalP 2.0 was the best tool among the ones using a feature-based approach. Even though PA-SUB 2.5 presented the highest metrics, it should be taken into account that this tool was trained using all proteins reported in SWISS-PROT, which includes the protein set tested in this study, either as a BLAST search or as a training model. DA - 2009/5/7/ PY - 2009/5/7/ DO - 10.1186/1471-2105-10-134 UR - http://dx.doi.org/10.1186/1471-2105-10-134 ER - TY - SOUND TI - Weed Control in Athletic Fields AU - Miller, Grady DA - 2009/9/23/ PY - 2009/9/23/ ER - TY - CONF TI - Sports Turf Paint Research AU - Miller, Grady T2 - National Football League (NFL) Symposium C2 - 2009/3/3/ CY - Glendale, AZ DA - 2009/3/3/ PY - 2009/3/3/ ER - TY - SOUND TI - Sports Turf Management AU - Miller, Grady DA - 2009/5/28/ PY - 2009/5/28/ ER - TY - SOUND TI - Nutrition and Turfgrass Fertilizers for Golf Courses AU - Miller, Grady DA - 2009/2/5/ PY - 2009/2/5/ ER - TY - CONF TI - Potassium and Phosphorus Nutrition AU - Miller, Grady T2 - SE Turf Conference C2 - 2009/4/7/ CY - Wilmington, NC DA - 2009/4/7/ PY - 2009/4/7/ ER - TY - CONF TI - Warm Season Turf Management for Athletic Fields AU - Miller, Grady T2 - Sports Turf Managers Association of America meeting C2 - 2009/// CY - San Jose, CA DA - 2009/// PY - 2009/1/16/ ER - TY - CONF TI - Renovation of an Overused Soccer Field AU - Miller, Grady T2 - Western Turf Conference C2 - 2009/3/9/ CY - Hendersonville, NC DA - 2009/3/9/ PY - 2009/3/9/ ER - TY - CONF TI - Golf Course Fertility Programs AU - Miller, Grady T2 - Western Turf Conference C2 - 2009/3/9/ CY - Hendersonville, NC DA - 2009/3/9/ PY - 2009/3/9/ ER - TY - CONF TI - Cultivar Evaluations for Tall Fescue Drought Tolerance AU - Miller, Grady T2 - Turf Council of North Carolina Conference C2 - 2009/1/29/ CY - Raleigh, NC DA - 2009/1/29/ PY - 2009/1/29/ ER - TY - CONF TI - How to Find Information to Solve Your Problems AU - Miller, Grady T2 - Turf Council of North Carolina Conference C2 - 2009/1/28/ CY - Raleigh, NC DA - 2009/1/28/ PY - 2009/1/28/ ER - TY - CONF TI - Granular Fertilizer Programs for Sports Turf AU - Miller, Grady T2 - NC and SC Sports Turf Managers Association Meeting C2 - 2009/11/18/ CY - Myrtle Beach, SC DA - 2009/11/18/ PY - 2009/11/18/ ER - TY - CONF TI - Golf Course Fertilization Programs AU - Miller, Grady T2 - Tennessee Turfgrass Conference C2 - 2009/1/12/ CY - Franklin, TN DA - 2009/1/12/ PY - 2009/1/12/ ER - TY - SOUND TI - Granular and Foliar Fertilization AU - Miller, Grady DA - 2009/11/17/ PY - 2009/11/17/ ER - TY - CONF TI - Sports Turf Research AU - Miller, Grady T2 - Tennessee Turfgrass Conference C2 - 2009/1/12/ CY - Franklin, TN DA - 2009/1/12/ PY - 2009/1/12/ ER - TY - SOUND TI - Golf Course Fertilization Programs AU - Miller, Grady DA - 2009/3/19/ PY - 2009/3/19/ ER - TY - RPRT TI - Winterkill, not disease is causing june problems for warm-season turfgrasses AU - Miller, G.L. DA - 2009/6/19/ PY - 2009/6/19/ ER - TY - SOUND TI - New Turf Types AU - Miller, Grady DA - 2009/2/17/ PY - 2009/2/17/ ER - TY - SOUND TI - Current Trends in Turf Management AU - Miller, Grady DA - 2009/12/9/ PY - 2009/12/9/ ER - TY - SOUND TI - Tall Fescue Establishment and Management AU - Miller, Grady DA - 2009/2/3/ PY - 2009/2/3/ ER - TY - SOUND TI - Sports Turf Research Update AU - Miller, Grady DA - 2009/1/8/ PY - 2009/1/8/ ER - TY - SOUND TI - Practical Options and Strategies for Irrigation Management AU - Miller, Grady DA - 2009/12/8/ PY - 2009/12/8/ ER - TY - SOUND TI - Managing Sports Fields on a Minimum Budget AU - Miller, Grady DA - 2009/12/8/ PY - 2009/12/8/ ER - TY - CONF TI - Sports Turf Research AU - Miller, Grady T2 - Turf Center Funding Symposium C2 - 2009/6/9/ CY - Raleigh, NC DA - 2009/6/9/ PY - 2009/6/9/ ER - TY - SOUND TI - Sports Turf Research to Help You Manage Your Fields AU - Miller, Grady DA - 2009/12/3/ PY - 2009/12/3/ ER - TY - SOUND TI - Installation, and Programming of Smart Irrigation Systems AU - Miller, Grady DA - 2009/11/12/ PY - 2009/11/12/ ER - TY - CONF TI - Sports Turf Management and Weed Control Options AU - Miller, Grady T2 - Minor League Baseball Conference C2 - 2009/10/28/ CY - Durham, NC DA - 2009/10/28/ PY - 2009/10/28/ ER - TY - CONF TI - Managing Sports Fields for P&R AU - Miller, Grady T2 - NC Recreation and Parks Association Meeting C2 - 2009/9/30/ CY - Mororehead City, NC DA - 2009/9/30/ PY - 2009/9/30/ ER - TY - CONF TI - Sustainable Turf Care for Disease and Insect Prevention AU - Miller, Grady T2 - Triangle Landscape Symposium C2 - 2009/11/11/ CY - Doris Duke Educational Center, Durham DA - 2009/11/11/ PY - 2009/11/11/ ER - TY - SOUND TI - Foliar and Granular Fertilization for Sports Turfgrasses AU - Miller, Grady DA - 2009/10/20/ PY - 2009/10/20/ ER - TY - SOUND TI - Turf Management and Painting AU - Miller, Grady DA - 2009/9/16/ PY - 2009/9/16/ ER - TY - RPRT TI - Fertility program balancing conservation and plant health AU - Miller, G.L. A3 - North Carolina State University DA - 2009/3/9/ PY - 2009/3/9/ PB - North Carolina State University ER - TY - RPRT TI - The effects of athletic field paint on turfgrass growth processes AU - Miller, G. AU - Reynolds, C. AU - Brinton, S. A3 - North Carolina State University DA - 2009/3/17/ PY - 2009/3/17/ PB - North Carolina State University ER - TY - RPRT TI - How to get information to solve your turf problems AU - Miller, G.L. A3 - North Carolina State University DA - 2009/1/28/ PY - 2009/1/28/ PB - North Carolina State University ER - TY - RPRT TI - Cultivar evaluations for tall fescue drought tolerance and new zoysiagrasses for NC AU - Miller, G.L. A3 - North Carolina State University DA - 2009/1/29/ PY - 2009/1/29/ PB - North Carolina State University ER - TY - RPRT TI - Turf management update for Charlotte and Mecklenburg County AU - Miller, G.L. A3 - North Carolina State University DA - 2009/2/3/ PY - 2009/2/3/ PB - North Carolina State University ER - TY - RPRT TI - Fertility program balancing conservation and plant health. AU - Miller, G.L. A3 - North Carolina State University DA - 2009/3/9/ PY - 2009/3/9/ PB - North Carolina State University ER - TY - RPRT TI - Evaluation of national warm-season trials – bermudagrass, zoysiagrass, and St. Augustinegrass AU - Miller, G.L. A3 - North Carolina State University DA - 2009/8/12/ PY - 2009/8/12/ PB - North Carolina State University ER - TY - RPRT TI - It is time for fall seeding of tall fescue AU - Miller, G.L. A3 - North Carolina State University DA - 2009/8/31/ PY - 2009/8/31/ PB - North Carolina State University ER - TY - JOUR TI - Polystand vs. monostand AU - Miller, G.L. T2 - SportsTurf DA - 2009/// PY - 2009/// VL - 25 IS - 11 SP - 46 ER - TY - JOUR TI - Don’t abandon me! AU - Miller, G.L. T2 - SportsTurf DA - 2009/// PY - 2009/// VL - 25 IS - 9 SP - 46 ER - TY - JOUR TI - To seed or not to seed? AU - Miller, G.L. T2 - SportsTurf DA - 2009/// PY - 2009/// VL - 25 IS - 7 SP - 62 ER - TY - JOUR TI - Is K special? AU - Miller, G.L. T2 - SportsTurf DA - 2009/// PY - 2009/// VL - 25 IS - 5 SP - 58 ER - TY - JOUR TI - Shopping for a new grass AU - Miller, G.L. T2 - SportsTurf DA - 2009/// PY - 2009/// VL - 25 IS - 3 SP - 46 ER - TY - JOUR TI - Budget cutting AU - Miller, G.L. T2 - SportsTurf DA - 2009/// PY - 2009/// VL - 25 IS - 1 SP - 54 ER - TY - SOUND TI - Overview of NTEP Zoysiagrass AU - Miller, Grady DA - 2009/8/12/ PY - 2009/8/12/ ER - TY - SOUND TI - Overview of NTEP Bermudagrass AU - Miller, Grady DA - 2009/8/12/ PY - 2009/8/12/ ER - TY - MGZN TI - Key factors in managing sports fields AU - Miller, G.L. T2 - North Carolina Turfgrass DA - 2009/7// PY - 2009/7// SP - 8-13 ER - TY - MGZN TI - Where the grass is not always greener AU - Caldwell, D. AU - Bruneau, A. AU - Miller, G. T2 - North Carolina turfgrass DA - 2009/1// PY - 2009/1// SP - 22–23 ER - TY - MGZN TI - Selecting a lawn grass: tall fescue versus zoysiagrass AU - Miller, G.L. T2 - North Carolina Turfgrass DA - 2009/5// PY - 2009/5// SP - 14–19 ER - TY - MGZN TI - Fall seeding of tall fescue lawns AU - Reynolds, C. AU - Brinton, S. AU - Miller, G. T2 - North Carolina Turfgrass DA - 2009/9// PY - 2009/9// SP - 8–11 ER - TY - JOUR TI - Euphorbia virgata AU - Paul E. Berry, Dmitry Geltman DA - 2009/// PY - 2009/// UR - http://name.umdl.umich.edu/IC-HERB00IC-X-1334017%5DMICH-V-1334017 ER - TY - RPRT TI - Modifying Soil for Plant Growth around Your Home AU - Hoyt, G. AU - Heitman, J.L. AU - Osmond, D.L. AU - Cooke, A. A3 - North Carolina Cooperative Extension DA - 2009/// PY - 2009/// M1 - AG 439 70 M3 - North Carolina State Extension Publication PB - North Carolina Cooperative Extension SN - AG 439 70 ER - TY - CHAP TI - Harnessing quantitative genetics and genomics for understanding and improving complex traits in crops AU - Holland, J.B. AU - Cardinal, A.J. T2 - Drought Frontiers in Rice: Crop Improvement for Increased Rainfed Production PY - 2009/// DO - 10.1142/9789814280013_0008 SP - 123-136 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84970959798&partnerID=MN8TOARS ER - TY - CHAP TI - Biogenesis of Cellulose Nanofibrils by a Biological Nanomachine AU - Haigler, Candace H. AU - Roberts, Alison W. T2 - The Nanoscience and Technology of Renewable Biomaterials AB - This chapter contains sections titled: Introduction Background CesA Protein is a Major Component of the Plant CSC The Functional Operation of the CSC Phylogenetic Analysis Conclusion References PY - 2009/9/21/ DO - 10.1002/9781444307474.ch2 SP - 43-59 OP - PB - John Wiley & Sons, Ltd SN - 9781444307474 9781405167864 UR - http://dx.doi.org/10.1002/9781444307474.ch2 DB - Crossref ER - TY - JOUR TI - An Example Emphasizing Mass–Volume Relationships for Problem Solving in Soils AU - Heitman, J. L. AU - Vepraskas, M. J. T2 - Journal of Natural Resources and Life Sciences Education AB - Mass–volume relationships are a useful tool emphasized for problem solving in many geo‐science and engineering applications. These relationships also have useful applications in soil science. Developing soils students’ ability to utilize mass–volume relationships through schematic diagrams of soil phases (i.e., air, water, and solid) can help to facilitate cross‐discipline problem solving efforts encountered throughout their careers. The objective of this article is to provide an applied example emphasizing mass–volume relationships and schematic diagrams for problem solving in soils. The example is taken from a study in restoration of an organic wetland soil. Drainage of organic soils results in a reduction of horizon thickness, termed subsidence , through shrinkage, loss of buoyancy, and oxidation of organic matter. Knowing the amount of subsidence that has occurred is important in restoration efforts, but is difficult to determine from conditions post‐drainage at a given site. Scientists must make use of mass–volume relationship and inference to assess the amount of subsidence that has occurred. In this example, information about post‐drainage and offsite horizon thickness, bulk density, and sand content are used to develop an estimate of the amount of subsidence. General information about the site is presented followed by assumptions used to develop the solution. The problem, assumptions, and step‐by‐step solution are divided into parts to facilitate use as a homework example, lecture example, or group problem solving activity. Questions and discussion points are presented to encourage student development of their own solution to the problem. DA - 2009/// PY - 2009/// DO - 10.4195/jnrlse.2008.0007n VL - 38 IS - 1 SP - 140 LA - en OP - SN - 1539-1582 UR - http://dx.doi.org/10.4195/jnrlse.2008.0007n DB - Crossref ER - TY - CONF TI - Design, contruction, and field evaluation of a lysimeter system for determining turfgrass water use AU - Wherley, B. AU - Sinclair, T. AU - Dukes, M. AU - Miller, G. C2 - 2009/// C3 - Proceedings of Florida State Horticultural Society DA - 2009/// ER - TY - CONF TI - SSR allelic diversity shifts in runner-type peanut breeding AU - Milla-Lewis, S.R. AU - Zuleta, M.C. AU - Isleib, T.G. C2 - 2009/// C3 - Proceedings of the American Peanut Research and Education Society DA - 2009/// VL - 41 SP - 40–41 ER - TY - CONF TI - Release of ‘Bailey’ virginia-type peanut cultivar AU - Copeland, S.C. AU - Isleib, T.G. AU - Milla-Lewis, S.R. AU - Shew, B.B. AU - Hollowell, J.E. AU - Pattee, H.E. AU - Sanders, T.H. AU - Dean, L.L. AU - Hendrix, K.W. AU - Balota, M. AU - Chapin, J.W. C2 - 2009/// C3 - Proc. Amer. Peanut Res. Educ. Soc. DA - 2009/// VL - 41 SP - 59–60 ER - TY - SOUND TI - Breeding better grasses for North Carolina AU - Milla-Lewis, S.R. DA - 2009/3/9/ PY - 2009/3/9/ M3 - invited presentation ER - TY - SOUND TI - Assessment of molecular variability within St. Augustinegrass cultivar ‘Raleigh’ using AFLP and SRAP markers AU - Milla-Lewis, S.R. AU - Lin, X. AU - Zuleta, M.C. AU - Chandra, A. AU - Kenworthy, K.E. AU - Martin, M.M. DA - 2009/11/1/ PY - 2009/11/1/ ER - TY - CHAP TI - Center for Environmental Farming Systems: Designing and Institutionalizing an Integrated Sustainable and Organic Agriculture Program AU - Creamer, Nancy G. AU - Mueller, J. Paul AU - Reberg-Horton, Chris AU - Schroeder-Moreno, Michelle AU - Washburn, Steve AU - O'Sullivan, John AU - Francis, Charles T2 - Organic Farming: The Ecological System A2 - Francis, Charles T3 - Agronomy Monographs AB - The Center for Environmental Farming Systems (CEFS) is a partnership among North Carolina State University (NCSU), North Carolina Agricultural & Technical State University, North Carolina Department of Agriculture and Consumer Services, and many nonprofit organizations and farmer groups. A survey of the College of Agriculture and Life Sciences faculty with sustainable agriculture interests revealed that ability to focus on holistic, long-term, interdisciplinary work not driven by single commodity interests was very important. To increase students' global awareness of the challenges to organic and sustainable agriculture internationally, a study-abroad course, Sustainability of Tropical Agroecosystems, was developed in a partnership with the University of Georgia and NCSU in 2005. In 2007 a strategic planning process was initiated through a committee made up of CEFS faculty, staff, and board members. CEFS also received grant funding in 2008 to provide leadership in developing a statewide action plan for developing a local food economy in North Carolina. PY - 2009/// DO - 10.2134/agronmonogr54.c12 SP - 253–282 PB - American Society of Agronomy, Crop Science Society of America, Soil Science Society of America SN - 9780891181897 9780891180760 SV - 54 UR - http://dx.doi.org/10.2134/agronmonogr54.c12 ER - TY - NEWS TI - Fertility and weed control in no-till organic production T2 - Organic Grain Project Newsletter PY - 2009/// UR - http://www.organicgrains.ncsu.edu/Newsletters/Dec2009.htm ER - TY - SOUND TI - Economic return of peanut grown in various row patterns with different herbicide inputs AU - Place, G.T. AU - Jordan, D.L. AU - Reberg-Horton, S.C. DA - 2009/// PY - 2009/// ER - TY - CHAP TI - Center for Environmental Farming Systems: Designing and institutionalizing an integrated sustainable and organic program at a land grant university AU - Creamer, N.G. AU - Mueller, J.P. AU - Reberg-Horton, S.C. AU - O'Sullivan, J. AU - Schroeder-Moreno, M. AU - Washburn, S. T2 - Organic Farming: the Ecological System A2 - Francis, C.A. PY - 2009/// PB - ASA, CSSA, and SSSA Book Publishing ER - TY - CONF TI - Breeding for weed suppressiveness: an initial approach to soybean genotype screening AU - Place, G.T. AU - Carter, T.E. AU - Reberg-Horton, S.C. C2 - 2009/// C3 - Proceedings of the 2009 Weed Science Society of America annual meeting DA - 2009/// ER - TY - SOUND TI - Breeding for weed suppressiveness: an initial approach to soybean genotype screening AU - Place, G.T. AU - Carter, T.E. AU - Reberg-Horton, S.C. DA - 2009/// PY - 2009/// ER - TY - CONF TI - Weed management tactics in organic no-till soybeans AU - Smith, A.N. AU - Mueller, J.P. AU - Reberg-Horton, S.C. C2 - 2009/// C3 - Proceedings of the 2009 Weed Science Society of America annual meeting DA - 2009/// ER - TY - NEWS TI - No-till organic grain project update T2 - Organic Grain Project Newsletter PY - 2009/9// UR - http://www.organicgrains.ncsu.edu/Newsletters/September2009.htm ER - TY - NEWS TI - No-till organic grain project update T2 - Organic Grain Project Newsletter PY - 2009/6// UR - http://www.organicgrains.ncsu.edu/Newsletters/June2009.htm ER - TY - NEWS TI - No-till organic grain production trials T2 - Organic Grain Project Newsletter PY - 2009/3// UR - http://www.organicgrains.ncsu.edu/Newsletters/March2009.htm ER - TY - NEWS TI - New project: organic crop breeding T2 - Organic Grain Project Newsletter PY - 2009/// UR - http://www.organicgrains.ncsu.edu/Newsletters/September2009.htm ER - TY - SOUND TI - Improved weed competitiveness in soybean screening tactics and traits of interest AU - Place, G.T. AU - Carter, T.E. AU - Reberg-Horton, S.C. DA - 2009/// PY - 2009/// ER - TY - SOUND TI - Identification of competitive soybean genotypes and soybean traits of interest in weed suppression AU - Place, G.T. AU - Carter, T.E. AU - Reberg-Horton, S.C. DA - 2009/// PY - 2009/// ER - TY - CONF TI - Transitioning to organic crop production: can conservation tillage practices be effective? AU - Meijer, A.D. AU - Hubers, D.L. AU - Crozier, C.R. AU - Reberg-Horton, C. AU - Hamilton, M. C2 - 2009/// C3 - Proceedings from the Southern Conservation Agriculture Systems Conference DA - 2009/// ER - TY - JOUR TI - Impact of weed management practices on grapevine growth and yield components AU - Sanguankeo, P.P. AU - Leon, R.G. AU - Malone, J. T2 - Weed Science AB - The need for reducing costs and making grape production more sustainable has prompted the search for alternative weed control practices that optimize production while maintaining profits. For this reason, it is imperative to understand how different weed management practices modify vine–weed interactions. In the present study, we evaluated the effect on weed growth and Zinfandel grapevine growth and production of five weed control practices: (1) flumioxazin, (2) simazine, (3) cultivation, (4) cover crop, and (5) untreated control. The herbicide treatments had the lowest weed biomass, followed by the cultivation, being approximately 10 and 2 times lower than the weed biomass of either the cover crop or untreated control treatments, respectively. However, the differences in grape yield were not as evident. In 2006, a rainy year, the herbicides and cultivation treatments did not differ in grape yield, but the cover crop and untreated control had a reduction of approximately 20% compared with the other treatments. In 2007, a dry year, in comparison to the herbicide treatments, the grape yield reductions of cultivation were around 22%, and those of the cover crop and untreated control were around 48%. Although the cover crop reduced grape yield, it suppressed weed species considered important, such as horseweed, panicle willowherb, scarlet pimpernel, and sowthistle. Also, it was concluded that vines can tolerate a certain amount of weed competition, and that properly timed postemergence control actions (e.g., cultivation or POST herbicides) could provide the necessary level of control to obtain the desired yields. However, under limited soil moisture conditions, the use of PRE herbicides could prove important to maintain vine yield and vigor. DA - 2009/// PY - 2009/// DO - 10.1614/ws-08-100.1 VL - 57 IS - 01 SP - 103–107 KW - Weed suppression KW - cover crop KW - competition KW - cultivation KW - weed community KW - diversity ER - TY - JOUR TI - Alternativas de control para el manejo de malezas en banano organico en establecimiento AU - Laforest, S. AU - Vedia, M. AU - Leon, R. T2 - Tierra Tropical DA - 2009/// PY - 2009/// VL - 5 SP - 225–235 ER - TY - JOUR TI - Genomics: An Evolving Science in Peanut AU - Stalker, H. T. AU - Weissinger, A. K. AU - Milla-Lewis, S. AU - Holbrook, C. C. T2 - Peanut Science AB - Abstract Genomic spcience offers new research tools to explore the function of genes and their effects on plants and animals. Arachis hypogaea is a polyploid species of relatively recent origin and molecular analyses with technologies available in the 1980s and 1990s resulted in little progress in the cultivated species because of apparent lack of molecular variation. Large numbers of polymorphisms existing in wild Arachis species led to evolutionary and gene introgression studies. High throughput genomic sequencing technologies have greatly expanded the possibilities for investigating gene function, but techniques are sufficiently expensive that most federal funding has been directed toward model species and ‘major’ crops. Peanut has lagged behind many other crops, but the number of researchers working on the species in the U.S. and internationally has greatly increased during recent years. In an effort to bring researchers who work with a number of legume crops together to discuss common goals, a national strategic planning workshop was held in 2001 which led to the U.S. Legume Crops Genomics Initiative. A second workshop was held in 2004 to develop a plan with specific objectives for cross-legume genomics research and to outline milestones for accomplishments. Specifically for peanut, a genomics strategic planning workshop was organized at Atlanta in 2004 by the American Peanut Council. A broad view of genomic science was adopted and goals were set by participants to include (a) improving the utility of genetic tools for peanut genomics research, (b) improving the efficacy of technology for gene manipulation in genomics, (c) developing a framework for assembling the peanut genetic blueprint, (d) improving knowledge of gene identification and regulation, and (e) providing bioinformatic management of peanut biological information. Teams of researchers, including molecular biologists, plant breeders, pathologists, and many other disciplines need to be developed to fully utilize the potential of genomics for peanut improvement. DA - 2009/1// PY - 2009/1// DO - 10.3146/at07-006.1 VL - 36 IS - 1 SP - 2-10 ER - TY - JOUR TI - The fungal-mineral interface: Challenges and considerations of micro-analytical developments AU - Smits, M.M. AU - Herrmann, A.M. AU - Duane, M. AU - Duckworth, O.W. AU - Bonneville, S. AU - Benning, L.G. AU - Lundström, U. T2 - Fungal Biology Reviews AB - Over recent years, the role of fungi, especially mycorrhizal fungi, in the weathering of rock-forming minerals has been increasingly recognised. Much of our understanding of the effects of fungi on mineral weathering is based on macroscopic studies. However, the ability of fungi to translocate materials, including organic acids and siderophores, to specific areas of a mineral surface leads to significant spatial heterogeneity in the weathering process. Thus, geomycologists are confronted with unique challenges of how to comprehend and quantify such a high degree of diversity and complicated arrays of interactions. Recent advances in experimental and analytical techniques have increased our ability to probe the fungal–mineral interface at the resolution necessary to decouple significant biogeochemical processes. Modern microscopy, spectroscopy, mass spectrometry, wet chemistry, and scattering techniques allow for the selective extraction of physical, chemical, and structural data at the micro- to nano-scale. These techniques offer exciting possibilities to study fungal–mineral interactions at the scale of individual hyphae. In this review, we give an overview of some of these techniques with their characteristics, advantages and limitations, and how they can be used to further our understanding of biotic mineral weathering. DA - 2009/// PY - 2009/// DO - 10.1016/j.fbr.2009.11.001 VL - 23 IS - 4 SP - 122-131 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-77954861346&partnerID=MN8TOARS ER - TY - CONF TI - Qualitative powdery mildew mapping update AU - Murphy, J. P. AU - Maxwell, J. J. AU - Miranda, L. M. AU - Lyerly, J. H. AU - Parks, W. R. AU - Srnic, G. AU - Perugini, L. AU - Cowger, C. AU - Marshall, D. AU - Van Esbroeck, G. AU - Brown-Guedira, G. AU - Jarrett, S. G. AU - Kolmer, J. C2 - 2009/// C3 - Eastern Wheat Workers/Southern Small Grain Workers NCERA184 Conference DA - 2009/// SP - 28-30 PB - Baltimore, Md.: Eastern Wheat Workers/Southern Small Grain Workers ER - TY - CONF TI - Advances in breeding for winter hardiness in oats C2 - 2009/// C3 - Proceedings of the Annual Meeting, American Society of Agronomy DA - 2009/// ER - TY - JOUR TI - Water quality improvements using modified sediment control systems on construction sites AU - McLaughlin, R. A. AU - Hayes, S. A. AU - Clinton, D. L. AU - McCaleb, M. S. AU - Jennings, G. D. T2 - Transactions of the ASABE AB - A study of the water quality of discharges from three different sediment control systems was conducted on a large construction site in North Carolina. Samples were obtained during storm events at the outlets of 11 of these systems using automatic samplers. Turbidity and total suspended solids (TSS) were measured, and a storm-weighted average (SWA) was determined for the systems. Water discharged from five standard sediment traps with rock dam outlets and unlined diversion ditches with rock check dams had an SWA turbidity of 4,320 nephelometric turbidity units (NTU) and an SWA peak of 12,640 NTU over a total of 26 storm events. The representative TSS values were 4,130 and 11,800 mg L-1, respectively. Measurements of runoff entering and exiting the traps suggested that heavy sediment was being captured, but turbidity was not reduced. Three traps with modifications including forebays, porous baffles, improved ditch stabilization (lining, additional check dams), and polyacrylamide application had SWA and peak turbidity of 990 and 1,580 NTU, respectively, over a total of 31 events. Total suspended solids were also much lower, at 740 and 1,810 mg L-1, respectively. Three basins with these same modifications, but with surface outlets, had somewhat higher average SWA values (1,560 NTU, 820 mg L-1), suggesting that the outlet type may not improve discharge water quality above the benefits of the other modifications to the standard sediment trap. However, when one of the latter systems was at optimal function, turbidity was reduced to below the receiving stream water levels (<100 NTU). These results strongly suggest that relatively simple modifications of commonly employed sediment trapping systems can dramatically improve discharge water quality and reduce the impacts on receiving waters. DA - 2009/// PY - 2009/// DO - 10.13031/2013.29214 VL - 52 IS - 6 SP - 1859-1867 ER - TY - JOUR TI - Molecular genetic description of the cryptic wheat-Aegilops geniculata introgression carrying rust resistance genes Lr57 and Yr40 using wheat ESTs and synteny with rice AU - Kuraparthy, Vasu AU - Sood, Shilpa AU - Gill, Bikram S. T2 - GENOME AB - The cryptic wheat–alien translocation T5DL·5DS-5M g S(0.95), with leaf rust and stripe rust resistance genes Lr57 and Yr40 transferred from Aegilops geniculata (U g M g ) into common wheat, was further analyzed. Molecular genetic analysis using physically mapped ESTs showed that the alien segment in T5DL·5DS-5M g S(0.95) represented only a fraction of the wheat deletion bin 5DS2-0.78-1.00 and was less than 3.3 cM in length in the diploid wheat genetic map. Comparative genomic analysis indicated a high level of colinearity between the distal region of the long arm of chromosome 12 of rice and the genomic region spanning the Lr57 and Yr40 genes in wheat. The alien segment with genes Lr57 and Yr40 corresponds to fewer than four overlapping BAC or PAC clones of the syntenic rice chromosome arm 12L. The wheat–alien translocation breakpoint in T5DL·5DS-5M g S(0.95) was further localized to a single BAC clone of the syntenic rice genomic sequence. The small size of the terminal wheat–alien translocation, as established precisely with respect to Chinese Spring deletion bins and the syntenic rice genomic sequence, further confirmed the escaping nature of cryptic wheat–alien translocations in introgressive breeding. The molecular genetic resources and information developed in the present study will facilitate further fine-scale physical mapping and map-based cloning of the Lr57 and Yr40 genes. DA - 2009/12// PY - 2009/12// DO - 10.1139/G09-076 VL - 52 IS - 12 SP - 1025-1036 SN - 1480-3321 KW - wheat KW - rust resistance KW - alien introgression KW - comparative mapping KW - synteny ER - TY - CONF TI - Delay analysis and design exploration for 3D SRAM AU - Chen, X. AU - Davis, W. R. AB - The emerging three-dimension (3D) integration technology provides a solution to reduce delay in SRAM. In this paper, we present a physical based delay analysis approach to explore 3D SRAM design options. Our analysis can be used to optimize the 3D SRAM timing performance at both sub-array and system level. Design examples based on the MITLL 3D process are constructed to demonstrate the trade-offs. As the analysis results show, the optimized 3D sub-array provides up to 20% extra improvement for SRAM access time reduction. C2 - 2009/// C3 - 2009 IEEE International Conference on 3d Systems Integration DA - 2009/// DO - 10.1109/3dic.2009.5306558 SP - 244-247 ER - TY - JOUR TI - BORON MOBILITY IN EUCALYPTUS CLONES AU - Sao Jose, Jackson Freitas AU - Silva, Ivo Ribeiro AU - Barros, Nairam Felix AU - Novais, Roberto Ferreira AU - Silva, Eulene Francisco AU - Smyth, Thomas Jot AU - Leite, Fernando Palha AU - Nunes, Flancer Novais AU - Gebrim, Fabricio Oliveira T2 - REVISTA BRASILEIRA DE CIENCIA DO SOLO AB - Understanding the magnitude of B mobility in eucalyptus may help to select clones that are more efficient for B use and to design new practices of B fertilization. This study consisted of five experiments with three eucalyptus clones (129, 57 and 58) where the response to and mobility of B were evaluated. Results indicated that clone 129 was less sensitive to B deficiency than clones 68 and 57, apparently due to its ability to translocate B previously absorbed via root systems to younger tissues when B in solution became limiting. Translocation also occurred when B was applied as boric acid only once to a single mature leaf, resulting in higher B concentration in roots, stems and younger leaves. The growth of B-deficient plants was also recovere by a single foliar application of B to a mature leaf. This mobility was greater, when foliar-applied B was supplied in complexed (boric acid + manitol) than in non-complexed form (boric acid alone). When the root system of clone 129 was split in two solution compartments, B supplied to one root compartment was translocated to the shoot and back to the roots in the other compartment, improving the B status and growth. Thus, it appears that B is relatively mobile in eucalyptus, especially in clone 129, and its higher mobility could be due to the presence of an organic compound such as manitol, able to complex B. DA - 2009/// PY - 2009/// DO - 10.1590/s0100-06832009000600022 VL - 33 IS - 6 SP - 1733-1744 SN - 0100-0683 KW - micronutrient KW - forest nutrition KW - translocation KW - polyol ER - TY - JOUR TI - Wettability and Hysteresis Effects on Water Sorption in Relatively Dry Soil AU - Davis, Dedrick D. AU - Horton, Robert AU - Heitman, Joshua L. AU - Ren, Tusheng T2 - Soil Science Society of America Journal AB - The soil water retention curve (SWRC) is a key tool for understanding the fundamental relationship between soil moisture content and its associated energy. The objective of this study was to measure soil water retention including hysteresis at the dry end of the SWRC and to examine the effect of wettability on the SWRCs of two wettable soils and their hydrophobized counterparts. Two conditions, wettable and hydrophobic, were measured for each soil. The method used to measure the SWRCs was vapor equilibration over salt solutions of known osmotic potentials. Free water in the form of individual droplets was found to be present at the surface of the unwashed hydrophobic soils due to decreases in the osmotic potential during the hydrophobizing process. Water droplets did not form on the hydrophilic and washed hydrophobic soils. Soil wettability was found to affect soil water retention in relatively dry soil. The hydrophilic soils used in this study exhibited significant hysteresis in the water potential range of −2.3 to −19.2 MPa. Soil wettability and hysteresis should be considered when studying water sorption and desorption in relatively dry soil. DA - 2009/11// PY - 2009/11// DO - 10.2136/sssaj2009.00028N VL - 73 IS - 6 SP - 1947-1951 J2 - Soil Sci. Soc. Am. J. LA - en OP - SN - 0361-5995 UR - http://dx.doi.org/10.2136/sssaj2009.00028n DB - Crossref ER - TY - JOUR TI - FoxJ1-dependent gene expression is required for differentiation of radial glia into ependymal cells and a subset of astrocytes in the postnatal brain AU - Jacquet, Benoit V. AU - Salinas-Mondragon, Raul AU - Liang, Huixuan AU - Therit, Blair AU - Buie, Justin D. AU - Dykstra, Michael AU - Campbell, Kenneth AU - Ostrowski, Lawrence E. AU - Brody, Steven L. AU - Ghashghaei, H. Troy T2 - DEVELOPMENT AB - Neuronal specification occurs at the periventricular surface of the embryonic central nervous system. During early postnatal periods, radial glial cells in various ventricular zones of the brain differentiate into ependymal cells and astrocytes. However, mechanisms that drive this time- and cell-specific differentiation remain largely unknown. Here, we show that expression of the forkhead transcription factor FoxJ1 in mice is required for differentiation into ependymal cells and a small subset of FoxJ1+ astrocytes in the lateral ventricles, where these cells form a postnatal neural stem cell niche. Moreover, we show that a subset of FoxJ1+ cells harvested from the stem cell niche can self-renew and possess neurogenic potential. Using a transcriptome comparison of FoxJ1-null and wild-type microdissected tissue, we identified candidate genes regulated by FoxJ1 during early postnatal development. The list includes a significant number of microtubule-associated proteins, some of which form a protein complex that could regulate the transport of basal bodies to the ventricular surface of differentiating ependymal cells during FoxJ1-dependent ciliogenesis. Our results suggest that time- and cell-specific expression of FoxJ1 in the brain acts on an array of target genes to regulate the differentiation of ependymal cells and a small subset of astrocytes in the adult stem cell niche. DA - 2009/12/1/ PY - 2009/12/1/ DO - 10.1242/dev.041129 VL - 136 IS - 23 SP - 4021-4031 SN - 1477-9129 KW - Subventricular zone KW - Adult stem cell niche KW - Ependymal cells KW - Astrocytes KW - FoxJ1 KW - Mouse ER - TY - JOUR TI - Plant cell calcium-rich environment enhances thermostability of recombinantly produced α-amylase from the hyperthermophilic bacterium Thermotoga maritime AU - Santa-Maria, Monica C. AU - Chou, Chung-Jung AU - Yencho, G. Craig AU - Haigler, Candace H. AU - Thompson, William F. AU - Kelly, Robert M. AU - Sosinski, Bryon T2 - Biotechnology and Bioengineering AB - Abstract In the industrial processing of starch for sugar syrup and ethanol production, a liquefaction step is involved where starch is initially solubilized at high temperature and partially hydrolyzed with a thermostable and thermoactive α‐amylase. Most amylases require calcium as a cofactor for their activity and stability, therefore calcium, along with the thermostable enzyme, are typically added to the starch mixture during enzymatic liquefaction, thereby increasing process costs. An attractive alternative would be to produce the enzyme directly in the tissue to be treated. In a proof of concept study, tobacco cell cultures were used as model system to test in planta production of a hyperthermophilic α‐amylase from Thermotoga maritima . While comparable biochemical properties to recombinant production in Escherichia coli were observed, thermostability of the plant‐produced α‐amylase benefited significantly from high intrinsic calcium levels in the tobacco cells. The plant‐made enzyme retained 85% of its initial activity after 3 h incubation at 100°C, whereas the E. coli ‐produced enzyme was completely inactivated after 30 min under the same conditions. The addition of Ca 2+ or plant cell extracts from tobacco and sweetpotato to the E. coli ‐produced enzyme resulted in a similar stabilization, demonstrating the importance of a calcium‐rich environment for thermostability, as well as the advantage of producing this enzyme directly in plant cells where calcium is readily available. Biotechnol. Bioeng. 2009; 104: 947–956. © 2009 Wiley Periodicals, Inc. DA - 2009/12/1/ PY - 2009/12/1/ DO - 10.1002/bit.22468 VL - 104 IS - 5 SP - 947–956 SN - 0006-3592 1097-0290 UR - http://dx.doi.org/10.1002/bit.22468 KW - hyperthermophilic enzymes KW - starch processing KW - transgenic plants KW - tobacco NT1 Cell cultures KW - biofuel ER - TY - JOUR TI - Peanut Cultivar Response to Damage from Tobacco Thrips and Paraquat AU - Drake, Wendy L. AU - Jordan, David L. AU - Lassiter, Bridget R. AU - Johnson, P. Dewayne AU - Brandenburg, Rick L. AU - Royals, Brian M. T2 - AGRONOMY JOURNAL AB - Virginia market‐type peanut cultivars in North Carolina vary in the number of days following emergence required to reach optimum maturity, and concern over cultivar response to interactions of tobacco thrips ( Frankliniella fusca Hinds) damage in absence of in‐furrow insecticide and injury from paraquat exist with respect to cultivar selection. Experiments were conducted during 2007 and 2008 to determine if cultivars vary in response to interactions of the insecticide aldicarb (no aldicarb or aldicarb applied in the seed furrow at planting) and the herbicide paraquat (no paraquat or paraquat applied 24 to 28 d after peanut emergence, DAE). The cultivar VA 98R expressed more damage from tobacco thrips than the cultivars Gregory, Perry, or Phillips. Although vegetative growth parameters varied among cultivar, aldicarb, and paraquat treatments, pod yield and market grade characteristics were not affected by the interaction of experiment, cultivar, aldicarb, and paraquat or the interaction of cultivar, aldicarb, and paraquat. Damage from tobacco thrips in absence of aldicarb affected pod yield more than injury from paraquat. The combination of tobacco thrips damage in absence of aldicarb and injury from paraquat lowered pod yield compared with aldicarb‐treated peanut either with or without paraquat regardless of cultivar. These data suggest that recommendations on use of aldicarb for tobacco thrips control or paraquat for early season weed control should not vary based on cultivar selection when considering pod yield and market grade characteristics. DA - 2009/// PY - 2009/// DO - 10.2134/agronj2009.0185 VL - 101 IS - 6 SP - 1388-1393 SN - 1435-0645 ER - TY - JOUR TI - Sequence analysis of rice rubi3 promoter gene expression cassettes for improved transgene expression AU - Sivamani, Elumalai AU - Starmer, Joshua D. AU - Qu, Rongda T2 - PLANT SCIENCE AB - In a construct containing a GUS reporter gene driven by the 5′ regulatory elements from rubi3, expression was enhanced 4-fold when a 20-nucleotide (nt) GUS 5′ untranslated sequence was replaced with 9 nt sequences derived from rubi3′s second exon. The roles of the sequences immediately upstream from the GUS translation initiation codon, and their significance in gene expression, were investigated. Sequence analysis suggests that complementarity between sequences immediately 5′ of a translation initiation codon and the rice 17S rRNA may be responsible for the reduction in protein levels from constructs containing the GUS leader sequence. The results demonstrate an affect sequences immediately upstream from transgenic coding sequences have on expression, and when using the rubi3 5′ regulatory sequence in particular. DA - 2009/12// PY - 2009/12// DO - 10.1016/j.plantsci.2009.08.006 VL - 177 IS - 6 SP - 549-556 SN - 0168-9452 KW - Exon KW - GUS KW - IME KW - rRNA KW - rubi3 promoter KW - Translation ER - TY - JOUR TI - Seeding Rate Effects on Weed Control and Yield For Organic Soybean Production AU - Place, George T. AU - Reberg-Horton, Samuel Chris AU - Dunphy, Jim E. AU - Smith, Adam N. T2 - WEED TECHNOLOGY AB - The organic grain sector is one of the fastest growing sectors of the organic market, but farmers in the mid-Atlantic cannot meet the organic grain demand, including the demand for organic soybean. Weed management is cited by farmers as the largest challenge to organic soybean production. Recent soybean population studies show that lower seeding rates for genetically modified organism soybean farmers provide maximum economic return due to high seed technology fees and inexpensive herbicides. Such economic analysis may not be appropriate for organic soybean producers due to the absence of seed technology fees, stronger weed pressures, and price premiums for organic soybean. Soybean seeding rates in North Carolina have traditionally been suggested at approximately 247,000 live seeds/ha, depending on planting conditions. Higher seeding rates may result in a more competitive soybean population and better economic returns for organic soybean producers. Experiments were conducted in 2006 and 2007 to investigate seeding rates of 185,000, 309,000, 432,000, and 556,000 live seeds/ha. All rates were planted on 76-cm row spacing in organic and conventional weed management systems. Increased soybean seeding rates reduced weed ratings at three of the five sites. Increased soybean seeding rates also resulted in higher yield at three of the four sites. Maximum economic returns for organic treatments were achieved with the highest seeding rate in all sites. Results suggest that seeding rates as high as 556,000 live seeds/ha may provide organic soybean producers with better weed control, higher yield, and increased profits. DA - 2009/// PY - 2009/// DO - 10.1614/WT-08-134.1 VL - 23 IS - 4 SP - 497-502 SN - 1550-2740 KW - Alternative weed management KW - cultural weed control KW - organic grain production ER - TY - JOUR TI - Saccharification and Fermentation of Dilute-Acid-Pretreated Freeze-Dried Switchgrass AU - Yang, Ying AU - Sharma-Shivappa, Ratna R. AU - Burns, Joseph C. AU - Cheng, Jay T2 - ENERGY & FUELS AB - This study investigated the potential of three freeze-dried switchgrass germplasms (St6-1, St6-3E, and St6-3F) as whole plants or their stems and leaves for bioethanol production. Whole switchgrass germplasms contained 24.34−30.95% glucan, 14.68−18.58% xylan, and 17.39−19.46% lignin. Switchgrass samples were pretreated with dilute sulfuric acid at concentrations of 0.5, 1.0, or 1.5% (w/v) for 30, 45, or 60 min at 121 °C and 15 psi. Although lignin degradation was limited, over 80% hemicellulose solublization was observed, especially in leaf samples, and the removal could be enhanced by increasing the pretreatment intensity through acid concentration and treatment time adjustment. Within each germplasm, pretreated samples with the least lignin content or greatest percent hemicellulose (xylan and arabinan) solublization were hydrolyzed enzymatically by cellulase at 0, 15, or 30 filter paper units (FPU)/g of dry biomass supplemented with cellobiase. Although the addition of cellulase greatly improved cellulose to glucose conversion, no significant (p ≥ 0.05) differences were observed between activity levels of 15 and 30 FPU/g of dry biomass. Pretreatment significantly (p < 0.05) improved cellulose conversion in samples with the greatest hemicellulose solublization; complete cellulose hydrolysis was observed in some St6-3F samples. Fermentation of hydrolyzates with Saccharomyces cerevisiae (ATCC 24859) resulted in the greatest ethanol yield of 0.083 g of ethanol/g of raw St6-3F switchgrass whole plant, which was 60% of the theoretical yield. Results from this study demonstrated the potential of new switchgrass germplasms as energy crops for bioethanol production through dilute sulfuric acid pretreatment. DA - 2009/11// PY - 2009/11// DO - 10.1021/ef9003335 VL - 23 IS - 11 SP - 5626-5635 SN - 1520-5029 ER - TY - JOUR TI - Quantitative Trait Loci and Epistasis for Oat Winter-Hardiness Component Traits AU - Wooten, D. R. AU - Livingston, D. P., III AU - Lyerly, H. J. AU - Holland, J. B. AU - Jellen, E. N. AU - Marshall, D. S. AU - Murphy, J. P. T2 - CROP SCIENCE AB - ABSTRACT Winter hardiness is a complex trait and poor winter hardiness limits commercial production of winter oat ( Avena spp.). The objective of this study was to identify quantitative trait loci (QTL) for five winter‐hardiness component traits in a recombinant inbred line population derived from a cross between the winter‐tender cultivar Fulghum and the winter‐hardy cultivar Norline. Crown freezing tolerance, vernalization response, and photoperiod response were evaluated in controlled environment studies. Heading date and plant height were evaluated over two seasons in Kinston, NC, and winter field survival was evaluated in five environments over two seasons in the mountains of North Carolina and Virginia. A partial genetic linkage map of regions believed to affect winter hardiness was developed using restriction fragment length polymorphism and simple sequence repeat markers. Most QTL were located on linkage groups FN3, FN22, and FN24. Quantitative trait loci were identified for all traits except photoperiod response, and epistatic interactions were identified for winter field survival, crown freezing tolerance, vernalization response, and plant height. Major QTL for winter field survival ( R 2 = 35%) and crown freezing tolerance ( R 2 = 53%) were identified on linkage group FN3, which was associated with an intergenomic reciprocal translocation between chromosomes 7C and 17. DA - 2009/// PY - 2009/// DO - 10.2135/cropsci2008.10.0612 VL - 49 IS - 6 SP - 1989-1998 SN - 1435-0653 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-70749094348&partnerID=MN8TOARS ER - TY - JOUR TI - MlAG12: a Triticum timopheevii-derived powdery mildew resistance gene in common wheat on chromosome 7AL AU - Maxwell, Judd J. AU - Lyerly, Jeanette H. AU - Cowger, Christina AU - Marshall, David AU - Brown-Guedira, Gina AU - Murphy, J. Paul T2 - THEORETICAL AND APPLIED GENETICS DA - 2009/11// PY - 2009/11// DO - 10.1007/s00122-009-1150-y VL - 119 IS - 8 SP - 1489-1495 SN - 1432-2242 ER - TY - JOUR TI - Microsatellite-based Analysis of Tobacco (Nicotiana tabacum L.) Genetic Resources AU - Moon, H. S. AU - Nifong, J. M. AU - Nicholson, J. S. AU - Heineman, A. AU - Lion, K. AU - Hoeven, R. AU - Hayes, A. J. AU - Lewis, R. S. T2 - CROP SCIENCE AB - ABSTRACT Little is currently known about the genetic variation within diverse gene pools of cultivated tobacco ( Nicotiana tabacum L.). Knowledge in this area could aid in future germplasm maintenance activities, provide additional information in the area of N. tabacum population genetics, and assist in selection of materials for breeding or genetic investigations. To this end, 702 N. tabacum accessions from the U.S. Nicotiana Germplasm Collection were genotyped with 70 microsatellite markers. A total of 1031 alleles were detected, with an average of 14.7 alleles per marker. Average gene diversity was quite large (0.7362) and was three times the value for a diverse population of U.S. flue‐cured tobacco. Cluster analysis using various distance coefficients generated seven consistent groups. Patterns of geographic‐specific clustering were frequent but not universal. An analysis of molecular variance for tobacco collected from Central and South America revealed that 92% of the total genetic variation among samples could be attributed to country‐specific subpopulations. There was also a significant level of population subdivision between country‐specific subpopulations, however. Tobacco samples collected from Peru had both the largest average gene diversity and the largest mean genetic distance, although N. tabacum collected from Mexico had the greatest allelic richness. Tobacco samples collected from Argentina were the most divergent subpopulation. DA - 2009/// PY - 2009/// DO - 10.2135/cropsci2009.01.0024 VL - 49 IS - 6 SP - 2149-2159 SN - 1435-0653 ER - TY - JOUR TI - METHODS TO EVALUATE NORMAL RAINFALL FOR SHORT-TERM WETLAND HYDROLOGY ASSESSMENT AU - Sumner, Jaclyn P. AU - Vepraskas, Michael J. AU - Kolka, Randall K. T2 - WETLANDS AB - Identifying sites meeting wetland hydrology requirements is simple when long-term (> 10 years) records are available. Because such data are rare, we hypothesized that a single-year of hydrology data could be used to reach the same conclusion as with long-term data, if the data were obtained during a period of normal or below normal rainfall. Long-term (40–45 years) water-table and rainfall data were obtained for two sites in North Carolina (with modeling), and one site in Minnesota (direct measurements). Single-year wetland hydrology assessments were made using two-rainfall assessment procedures recommended by the U.S. Army Corps of Engineers for their Wetland Hydrology Technical Standard, and two other rainfall assessment methods that were modifications of those procedures. Percentages of years meeting wetland-hydrology conditions during normal or drier than normal periods were identified for each plot with each rainfall assessment method. Although the wetland hydrology criterion was met in over 90% of the years across all plots using the long-term records, the four assessment techniques predicted the criterion was met in 41–81% of the years. Based on our results, we recommend that either the Direct Antecedent Rainfall Evaluation Method, or its modified version, be used for wetland hydrology assessment. DA - 2009/9// PY - 2009/9// DO - 10.1672/09-026d.1 VL - 29 IS - 3 SP - 1049-1062 SN - 1943-6246 KW - technical standards KW - water table KW - wetland delineation KW - WETS data ER - TY - JOUR TI - Fate of N-15-Nitrate Applied to a Bermudagrass System: Assimilation Profiles in Different Seasons AU - Wherley, Benjamin G. AU - Shi, Wei AU - Bowman, Daniel C. AU - Rufty, Thomas W. T2 - CROP SCIENCE AB - ABSTRACT Pressures to protect water quality and water shortages are leading to increased applications of effluent water on turfgrasses, and there are pressures to disperse effluent throughout the year. These experiments investigated NO 3 − uptake efficiency by Tifway bermudagrass [ Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt Davy] during growth and dormancy cycles, and thus the potential to filter effluent at different times of the year. Turf–soil cores from field plots were placed in controlled environment chambers and fed solutions with 15 N‐NO 3 − Nitrate uptake was, as expected, greatest in summer when plants were growing rapidly. Less than 10% of applied NO 3 − was recovered from soil after 3 d. The microbial population was elevated, but little 15 N was found in soil microbial or organic fractions. The system was inefficient in winter when bermudagrass was dormant; 80 to 90% of the NO 3 − remained in soil after 16 d. The system was more efficient than expected in spring and fall transition months, with 80 to 90% assimilated within 1 wk. A large portion of applied 15 N was held belowground in rhizomes and roots. Competitiveness of the microbial population was greater in transition months than during rapid bermudagrass growth in August when the population itself was larger. Although seasonal differences occurred, bermudagrass roots were consistently more competitive than the microbial population for applied 15 N, an observation very different from that with other grass systems. DA - 2009/// PY - 2009/// DO - 10.2135/cropsci2008.08.0468 VL - 49 IS - 6 SP - 2291-2301 SN - 1435-0653 ER - TY - JOUR TI - The Genetic Architecture of Maize Flowering Time AU - Buckler, Edward S. AU - Holland, James B. AU - Bradbury, Peter J. AU - Acharya, Charlotte B. AU - Brown, Patrick J. AU - Browne, Chris AU - Ersoz, Elhan AU - Flint-Garcia, Sherry AU - Garcia, Arturo AU - Glaubitz, Jeffrey C. AU - Goodman, Major M. AU - Harjes, Carlos AU - Guill, Kate AU - Kroon, Dallas E. AU - Larsson, Sara AU - Lepak, Nicholas K. AU - Li, Huihui AU - Mitchell, Sharon E. AU - Pressoir, Gael AU - Peiffer, Jason A. AU - Rosas, Marco Oropeza AU - Rocheford, Torbert R. AU - Cinta Romay, M. AU - Romero, Susan AU - Salvo, Stella AU - Sanchez Villeda, Hector AU - Silva, H. Sofia AU - Sun, Qi AU - Tian, Feng AU - Upadyayula, Narasimham AU - Ware, Doreen AU - Yates, Heather AU - Yu, Jianming AU - Zhang, Zhiwu AU - Kresovich, Stephen AU - McMullen, Michael D. T2 - SCIENCE AB - Flowering time is a complex trait that controls adaptation of plants to their local environment in the outcrossing species Zea mays (maize). We dissected variation for flowering time with a set of 5000 recombinant inbred lines (maize Nested Association Mapping population, NAM). Nearly a million plants were assayed in eight environments but showed no evidence for any single large-effect quantitative trait loci (QTLs). Instead, we identified evidence for numerous small-effect QTLs shared among families; however, allelic effects differ across founder lines. We identified no individual QTLs at which allelic effects are determined by geographic origin or large effects for epistasis or environmental interactions. Thus, a simple additive model accurately predicts flowering time for maize, in contrast to the genetic architecture observed in the selfing plant species rice and Arabidopsis. DA - 2009/8/7/ PY - 2009/8/7/ DO - 10.1126/science.1174276 VL - 325 IS - 5941 SP - 714-718 SN - 1095-9203 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-68449083317&partnerID=MN8TOARS ER - TY - JOUR TI - SOILS AND AGRICULTURE IN CENTRAL-WEST AND NORTH BRAZIL AU - Buol, Stanley W. T2 - SCIENTIA AGRICOLA AB - Modern soil science, spearheaded by research in Brazil has facilitated the utilization of vast areas of previously uncultivated soil long considered unsuitable for human food production into highly productive agricultural land. Naturally acid soils with high contents of aluminum and iron oxides and low CEC values and organic matter contents long considered insurmountable obstacles to crop production in tropical latitudes could be extremely productive. With continued development of the infrastructure needed by commercial agriculture Brazil has the potential to lead the world in its quest to provide food for growing human populations. DA - 2009/// PY - 2009/// DO - 10.1590/S0103-90162009000500016 VL - 66 IS - 5 SP - 697-707 SN - 0103-9016 KW - Cerrado soils KW - Brazilian Amazon KW - Latossolos KW - Oxisols KW - Ultisols ER - TY - JOUR TI - Intake and Digestibility of 'Coastal' Bermudagrass Hay from Treated Swine Waste Using Subsurface Drip Irrigation AU - Burns, J. C. AU - Stone, K. C. AU - Hunt, P. G. AU - Vanotti, M. B. AU - Cantrell, K. B. AU - Fisher, D. S. T2 - JOURNAL OF ENVIRONMENTAL QUALITY AB - Waste handling systems for confined swine production in the upper South (approximately 32–37° N and 79–93° W) depend mainly on anaerobic lagoons and application of the waste effluent to cropland. The main objective of this study was to evaluate the quality of ‘Coastal’ bermudagrass [ Cynodon dactylon (L.) Pers.] hay receiving effluent generated from a raw swine waste treatment system designed to reduce P and K concentrations and delivered by subsurface drip irrigation (SDI) compared with hay produced from commercial N fertilizer. Eight treatments, consisting of commercial N fertilizer or effluent, each irrigated at two irrigation rates (75 and 100% of estimated evapotranspiration) and two lateral spacings (0.6 and 1.2 m), were compared with a control treatment of commercial N fertilizer without irrigation. Three harvests were taken in each of 2 yr and five of the six evaluated using wether sheep (30–45 kg). Greatest dry matter intake (DMI) per unit body weight occurred for the control vs. all irrigated treatments (1.94 vs. 1.77 kg 100 −1 kg; P = 0.02; SEM = 0.11). Among irrigated treatments, DMI was greatest from commercial N vs. effluent (1.81 vs. 1.71 kg 100 −1 kg; P = 0.05; SEM = 0.11). Dry matter intake was similar for the 75% rate treatments and the non‐irrigated treatment (mean, 1.87 kg 100 −1 kg) but was reduced for the 100% rate (1.94 vs. 1.72 kg 100 −1 kg; P = 0.03; SEM = 0.11). Hay from the 75% rate was more digestible than hay from the 100% rate (527 vs. 508 g kg −1 ; P = 0.03; SEM = 21). The SDI system functioned well, and lateral spacing did not alter hay quality. Treated waste from a raw waste treatment system was readily delivered by SDI at the recommended rate to produce bermudagrass hay of adequate quality for ruminant production systems. DA - 2009/// PY - 2009/// DO - 10.2134/jeq2008.0493 VL - 38 IS - 4 SP - 1749-1756 SN - 1537-2537 ER - TY - CONF TI - A variable-rate decision support tool AU - Havlin, J. L. AU - Heiniger, Ronnie C2 - 2009/// C3 - Precision Agriculture DA - 2009/// DO - 10.1007/s11119-009-9121-5 VL - 10 SP - 356–369 M1 - 4 ER - TY - JOUR TI - A synthetic auxin (NAA) suppresses secondary wall cellulose synthesis and enhances elongation in cultured cotton fiber AU - Singh, Bir AU - Cheek, Hannah D. AU - Haigler, Candace H. T2 - Plant Cell Reports DA - 2009/5/29/ PY - 2009/5/29/ DO - 10.1007/s00299-009-0714-2 VL - 28 IS - 7 SP - 1023-1032 J2 - Plant Cell Rep LA - en OP - SN - 0721-7714 1432-203X UR - http://dx.doi.org/10.1007/s00299-009-0714-2 DB - Crossref KW - Auxin KW - Cellulose KW - Cotton ovule culture KW - Fiber differentiation KW - Primary cell wall KW - Secondary cell wall ER - TY - JOUR TI - Leaching of Nutrients and Trace Elements from Stockpiled Turkey Litter into Soil AU - Shah, Sanjay B. AU - Hutchison, Kimberly J. AU - Hesterberg, Dean L. AU - Grabow, Garry L. AU - Huffman, Rodney L. AU - Hardy, David H. AU - Parsons, James T. T2 - JOURNAL OF ENVIRONMENTAL QUALITY AB - In addition to nutrients, poultry are fed trace elements (e.g., As) for therapeutic purposes. Although a large proportion of the nutrients are assimilated by the birds, nearly all of the As is excreted. Hence, turkey litter constituents can leach into the soil and contaminate shallow ground water when it is stockpiled uncovered on bare soil. This study quantified the leaching of turkey litter constituents from uncovered stockpiles into the underlying soil. Four stockpiles were placed on Orangeburg loamy sand in summer 2004 for 162 d; 14 d after their removal, four stockpiles were created over the same footprints and left over winter for 162 d. Soil samples at depths of 7.6 to 30.5 cm and 30.5 to 61 cm adjacent to and beneath the stockpiles were compared for pH, electrical conductivity, total C, dissolved organic C, N species, P, water-extractable (WE)-P, As, WE-As, Cu, Mn, and Zn. All WE constituents affected the 7.6- to 30.5-cm layer, and some leached deeper; for example, NH(4)(+)-N concentrations were 184 and 62 times higher in the shallow and deep layers, respectively. During winter stockpiling, WE-As concentrations beneath the stockpiles tripled and doubled in the 7.6- to 30.5-cm and 30.5- to 61-cm layers, respectively, with WE-As being primarily as As(V). Heavy dissolved organic C and WE-P leaching likely increased solubilization of soil As, although WE-As concentrations were low due to the Al-rich soil and low-As litter. When used as drinking water, shallow ground water should be monitored on farms with a history of litter stockpiling on bare soil; high litter As; and high soil As, Fe, and Mn concentrations. DA - 2009/// PY - 2009/// DO - 10.2134/jeq2007.0639 VL - 38 IS - 3 SP - 1053-1065 SN - 1537-2537 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-66649083862&partnerID=MN8TOARS ER - TY - JOUR TI - Landscape irrigation by evapotranspiration-based irrigation controllers under dry conditions in Southwest Florida AU - Davis, S. L. AU - Dukes, M. D. AU - Miller, G. L. T2 - AGRICULTURAL WATER MANAGEMENT AB - Due to high demand for aesthetically pleasing urban landscapes from continually increasing population in Florida, new methods must be explored for outdoor water conservation. Three brands of evapotranspiration (ET) controllers were selected based on positive water savings results in arid climates. ET controllers were evaluated on irrigation application compared to a time clock schedule intended to mimic homeowner irrigation schedules. Three ET controllers were tested: Toro Intelli-sense; ETwater Smart Controller 100; Weathermatic SL1600. Other time-based treatments were TIME, based on the historical net irrigation requirement and RTIME that was 60% of TIME. Each treatment was replicated four times for a total of twenty St. Augustinegrass plots which were irrigated through individual irrigation systems. Treatments were compared to each other and to a time-based schedule without rain sensor (TIME WORS) derived from TIME. The study period, August 2006 through November 2007, was dry compared to 30-year historical average rainfall. The ET controllers averaged 43% water savings compared to a time-based treatment without a rain sensor and were about twice as effective and reducing irrigation compared to a rain sensor alone. There were no differences in turfgrass quality across all treatments over the 15-month study. The controllers adjusted their irrigation schedules to the climatic demand effectively, with maximum savings of 60% during the winter 2006–2007 period and minimum savings of 9% during spring 2007 due to persistent dry conditions. RTIME had similar savings to the ET controllers compared to TIME WORS indicating that proper adjustment of time clocks could result in substantial irrigation savings. However, the ET controllers would offer consistent savings once programmed properly. DA - 2009/12// PY - 2009/12// DO - 10.1016/j.agwat.2009.08.005 VL - 96 IS - 12 SP - 1828-1836 SN - 1873-2283 KW - Drought KW - Turfgrass KW - Water conservation ER - TY - JOUR TI - Hydraulic Characteristics of Depositional Seals as Affected by Exchangeable Cations, Clay Mineralogy, and Polyacrylamide AU - Bhardwaj, A. K. AU - McLaughlin, R. A. AU - Shainberg, I. AU - Levy, G. J. T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - Depositional seals, formed when turbid waters infiltrate into soils, lead to a reduction in the hydraulic conductivity (HC) of soils and increased runoff. In this study, the effect of anionic polyacrylamide (PAM) on the HC and flocculation of depositional seals made of three clay minerals (montmorillonite, illite, and kaolinite), saturated with either Na or Ca, was investigated. A silt loam soil was packed in columns and leached with 5 g L −1 suspensions of the reference clays. Deposition of the clay particles on the soil surface formed seals. In the PAM treatment, dry granules of linear PAM were spread on the soil surface before the suspension application. Calcium seals were more permeable than Na seals in all the clay types, up to 26 times greater for montmorillonite. The HC of the seals for the clay minerals was in the order kaolinite (2.8–3.5 mm h −1 ) > illite (0.6–3.0 mm h −1 ) > montmorillonite (0.09–1.0 mm h −1 ). The addition of PAM generally enhanced clay flocculation, with the magnitude of the enhancement depending on the type of the exchangeable cation. The Na‐saturated seals in the three clay types had significantly higher initial HC with the PAM treatment. This increase, however, was transient except in Na‐illite. The impact of PAM on the degree of clay flocculation and floc density partially explained the effects of PAM on the HC of the depositional seals. An increase in clay flocculation or a decrease in floc density caused by PAM resulted in an increase in depositional seal HC. DA - 2009/// PY - 2009/// DO - 10.2136/sssaj2007.0426 VL - 73 IS - 3 SP - 910-918 SN - 1435-0661 ER - TY - JOUR TI - Genetic analysis of resistance to soil-borne wheat mosaic virus derived from Aegilops tauschii AU - Hall, M. D. AU - Brown-Guedira, G. AU - Klatt, A. AU - Fritz, A. K. T2 - EUPHYTICA DA - 2009/9// PY - 2009/9// DO - 10.1007/s10681-009-9910-y VL - 169 IS - 2 SP - 169-176 SN - 0014-2336 KW - Aegilops taushii KW - Disease resistance KW - Markers KW - Soil-borne wheat mosiac virus KW - Wheat ER - TY - JOUR TI - Functional Characterization of Phospholipid N-Methyltransferases from Arabidopsis and Soybean AU - Keogh, Matthew R. AU - Courtney, Polly D. AU - Kinney, Anthony J. AU - Dewey, Ralph E. T2 - JOURNAL OF BIOLOGICAL CHEMISTRY AB - Phospholipid N-methyltransferase (PLMT) enzymes catalyze the S-adenosylmethionine-dependent methylation of ethanolamine-containing phospholipids to produce the abundant membrane lipid phosphatidylcholine (PtdCho). In mammals and yeast, PLMT activities are required for the de novo synthesis of the choline headgroup found in PtdCho. PLMT enzyme activities have also been reported in plants, yet their roles in PtdCho biosynthesis are less clear because most plants can produce the choline headgroup entirely via soluble substrates, initiated by the methylation of free ethanolamine-phosphate. To gain further insights into the function of PLMT enzymes in plants, we isolated PLMT cDNAs from Arabidopsis and soybean (Glycine max) based upon primary amino acid sequence homology to the rat PLMT, phosphatidylethanolamine N-methyltransferase. Using a heterologous yeast expression system, it was shown that plant PLMTs methylate phosphatidylmonomethylethanolamine and phosphatidyldimethylethanolamine but cannot utilize phosphatidylethanolamine as a substrate. Identification of an Arabidopsis line containing a knock-out dissociator transposon insertion within the single copy AtPLMT gene allowed us to investigate the consequences of loss of PLMT function. Although the accumulation of the PLMT substrates phosphatidylmonomethylethanolamine and phosphatidyldimethylethanolamine was considerably elevated in the atplmt knock-out line, PtdCho levels remained normal, and no obvious differences were observed in plant morphology or development under standard growth conditions. However, because the metabolic routes through which PtdCho is synthesized in plants vary greatly among differing species, it is predicted that the degree with which PtdCho synthesis is dependent upon PLMT activities will also vary widely throughout the plant kingdom. DA - 2009/6/5/ PY - 2009/6/5/ DO - 10.1074/jbc.M109.005991 VL - 284 IS - 23 SP - 15439-15447 SN - 1083-351X ER - TY - JOUR TI - Activities of Nitrogen-Mineralization Enzymes Associated with Soil Aggregate Size Fractions of Three Tillage Systems AU - Muruganandam, Subathra AU - Israel, Daniel W. AU - Robarge, Wayne P. T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - Nitrogen mineralization occurring near the soil surface of agroecosystems determines the quantity of plant‐available N, and soil enzymes produced by microorganisms play significant roles in the N mineralization process. Tillage systems may influence soil microbial communities and N mineralization enzymes through alterations in total soil C and N. Soil aggregates of different sizes provide diverse microhabitats for microorganisms and therefore influence soil enzyme activities. Our objective was to test the hypothesis that activities of N mineralization enzymes increase with aggregate size and in no‐till compared with tilled systems. Potential activities of N ‐acetyl glucosaminidase (NAG), arylamidase, l ‐glutaminase, and l ‐asparaginase were measured in five aggregate size fractions (<0.25, 0.25–0.5, 0.5–1, 1–2, and 2–4 mm) obtained from soils of three long‐term (22‐yr) tillage systems (no‐till, chisel plow, and moldboard plow). All enzyme activities were significantly ( P < 0.05) greater in no‐till than in tilled systems and positively correlated ( P < 0.005) with potential N mineralization. Potential activities of NAG, l ‐glutaminase, and arylamidase were significantly greater ( P < 0.05) in the intermediate (0.5–1‐mm) aggregate size than in other size fractions. All enzyme activities were positively correlated with total soil C ( P < 0.0001), N ( P < 0.05), and microbial biomass C ( P < 0.05). Aggregate size had significant effects on NAG, arylamidase, and l ‐glutaminase activities but the magnitudes were small. Fungal biomarkers (18:2ω6c and 16:1ω5c) determined by the phospholipid fatty acid (PLFA) method were significantly greater in the no‐till than in tilled systems and positively correlated with all enzyme activities. This suggests that no‐till management enhances activities of N mineralization enzymes by enhancing the proportion of fungal organisms in the soil microbial community. DA - 2009/// PY - 2009/// DO - 10.2136/sssaj2008.0231 VL - 73 IS - 3 SP - 751-759 SN - 1435-0661 ER - TY - JOUR TI - Absorption, Translocation, and Metabolism of Glufosinate in Transgenic and Nontransgenic Cotton, Palmer Amaranth (Amaranthus palmeri), and Pitted Morningglory (Ipomoea lacunosa) AU - Everman, Wesley J. AU - Thomas, Walter E. AU - Burton, James D. AU - York, Alan C. AU - Wilcut, John W. T2 - WEED SCIENCE AB - Greenhouse studies were conducted to evaluate absorption, translocation, and metabolism of 14 C-glufosinate in glufosinate-resistant cotton, nontransgenic cotton, Palmer amaranth, and pitted morningglory. Cotton plants were treated at the four-leaf stage, whereas Palmer amaranth and pitted morningglory were treated at 7.5 and 10 cm, respectively. All plants were harvested at 1, 6, 24, 48, and 72 h after treatment (HAT). Absorption of 14 C-glufosinate was greater than 85% 24 h after treatment in Palmer amaranth. Absorption was less than 30% at all harvest intervals for glufosinate-resistant cotton, nontransgenic cotton, and pitted morningglory. At 24 HAT, 49 and 12% of radioactivity was translocated to regions above and below the treated leaf, respectively, in Palmer amaranth. Metabolites of 14 C-glufosinate were detected in all crop and weed species. Metabolism of 14 C-glufosinate was 16% or lower in nontransgenic cotton and pitted morningglory; however, metabolism rates were greater than 70% in glufosinate-resistant cotton 72 HAT. Intermediate metabolism was observed for Palmer amaranth, with metabolites comprising 20 to 30% of detectable radioactivity between 6 and 72 HAT. DA - 2009/// PY - 2009/// DO - 10.1614/WS-09-015.1 VL - 57 IS - 4 SP - 357-361 SN - 1550-2759 KW - Absorption KW - cotton KW - glufosinate KW - metabolism KW - translocation ER - TY - JOUR TI - A method for accelerated trait conversion in plant breeding AU - Lewis, Ramsey S. AU - Kernodle, S. P. T2 - THEORETICAL AND APPLIED GENETICS DA - 2009/5// PY - 2009/5// DO - 10.1007/s00122-009-0998-1 VL - 118 IS - 8 SP - 1499-1508 SN - 1432-2242 ER - TY - JOUR TI - A Specialized Outer Layer of the Primary Cell Wall Joins Elongating Cotton Fibers into Tissue-Like Bundles AU - Singh, Bir AU - Avci, Utku AU - Eichler Inwood, Sarah E. AU - Grimson, Mark J. AU - Landgraf, Jeff AU - Mohnen, Debra AU - Sørensen, Iben AU - Wilkerson, Curtis G. AU - Willats, William G.T. AU - Haigler, Candace H. T2 - Plant Physiology AB - Cotton (Gossypium hirsutum) provides the world's dominant renewable textile fiber, and cotton fiber is valued as a research model because of its extensive elongation and secondary wall thickening. Previously, it was assumed that fibers elongated as individual cells. In contrast, observation by cryo-field emission-scanning electron microscopy of cotton fibers developing in situ within the boll demonstrated that fibers elongate within tissue-like bundles. These bundles were entrained by twisting fiber tips and consolidated by adhesion of a cotton fiber middle lamella (CFML). The fiber bundles consolidated via the CFML ultimately formed a packet of fiber around each seed, which helps explain how thousands of cotton fibers achieve their great length within a confined space. The cell wall nature of the CFML was characterized using transmission electron microscopy, including polymer epitope labeling. Toward the end of elongation, up-regulation occurred in gene expression and enzyme activities related to cell wall hydrolysis, and targeted breakdown of the CFML restored fiber individuality. At the same time, losses occurred in certain cell wall polymer epitopes (as revealed by comprehensive microarray polymer profiling) and sugars within noncellulosic matrix components (as revealed by gas chromatography-mass spectrometry analysis of derivatized neutral and acidic glycosyl residues). Broadly, these data show that adhesion modulated by an outer layer of the primary wall can coordinate the extensive growth of a large group of cells and illustrate dynamic changes in primary wall structure and composition occurring during the differentiation of one cell type that spends only part of its life as a tissue. DA - 2009/4/15/ PY - 2009/4/15/ DO - 10.1104/pp.109.135459 VL - 150 IS - 2 SP - 684-699 J2 - Plant Physiol. LA - en OP - SN - 0032-0889 1532-2548 UR - http://dx.doi.org/10.1104/pp.109.135459 DB - Crossref ER - TY - JOUR TI - Weed Control and Yield with Flumioxazin, Fomesafen, and S-Metolachlor Systems for Glufosinate-Resistant Cotton Residual Weed Management AU - Everman, Wesley J. AU - Clewis, Scott B. AU - York, Alan C. AU - Wilcut, John W. T2 - WEED TECHNOLOGY AB - Field studies were conducted near Clayton, Lewiston, and Rocky Mount, NC in 2005 to evaluate weed control and cotton response to preemergence treatments of pendimethalin alone or in a tank mixture with fomesafen, postemergence treatments of glufosinate applied alone or in a tank mixture with S -metolachlor, and POST-directed treatments of glufosinate in a tank mixture with flumioxazin or prometryn. Excellent weed control (> 91%) was observed where at least two applications were made in addition to glufosinate early postemergence (EPOST). A reduction in control of common lambsquarters (8%), goosegrass (20%), large crabgrass (18%), Palmer amaranth (13%), and pitted morningglory (9%) was observed when residual herbicides were not included in PRE or mid-POST programs. No differences in weed control or cotton lint yield were observed between POST-directed applications of glufosinate with flumioxazin compared to prometryn. Weed control programs containing three or more herbicide applications resulted in similar cotton lint yields at Clayton and Lewiston, and Rocky Mount showed the greatest variability with up to 590 kg/ha greater lint yield where fomesafen was included PRE compared to pendimethalin applied alone. Similarly, an increase in cotton lint yields of up to 200 kg/ha was observed where S -metolachlor was included mid-POST when compared to glufosinate applied alone, showing the importance of residual herbicides to help maintain optimal yields. Including additional modes of action with residual activity preemergence and postemergence provides a longer period of weed control, which helps maintain cotton lint yields. DA - 2009/// PY - 2009/// DO - 10.1614/WT-09-007.1 VL - 23 IS - 3 SP - 391-397 SN - 1550-2740 KW - Residual herbicides KW - resistance management KW - crop injury ER - TY - JOUR TI - Weed Control and Crop Response to Glufosinate Applied to 'PHY 485 WRF' Cotton AU - Culpepper, A. Stanley AU - York, Alan C. AU - Roberts, Phillip AU - Whitaker, Jared R. T2 - WEED TECHNOLOGY AB - Field experiments were conducted in Georgia to evaluate weed control and crop tolerance with glufosinate applied to ‘PHY 485 WRF®’ cotton. This glyphosate-resistant cotton also contains a gene, used as a selectable marker, for glufosinate resistance. Three experiments were maintained weed-free and focused on crop tolerance; a fourth experiment focused on control of pitted morningglory and glyphosate-resistant Palmer amaranth. In two experiments, PHY 485 WRF cotton was visibly injured 15 and 20% or less by glufosinate ammonium salt at 430 and 860 g ae/ha, respectively, applied POST two or three times. In a third experiment, glufosinate at 550 g/ha injured cotton up to 36%. Pyrithiobac or glyphosate mixed with glufosinate did not increase injury compared to glufosinate applied alone; S -metolachlor mixed with glufosinate increased injury by six to seven percentage points. Cotton injury was not detectable 14 to 21 d after glufosinate application, and cotton yields were not reduced by glufosinate or glufosinate mixtures. A program of pendimethalin PRE, glyphosate applied POST twice, and diuron plus MSMA POST-directed controlled glyphosate-resistant Palmer amaranth only 17% late in the season. S -metolachlor included with the initial glyphosate application did not increase control, and pyrithiobac increased late-season control by only 13 percentage points. Palmer amaranth was controlled 90% or more when glufosinate replaced glyphosate in the aforementioned system. Pitted morningglory was controlled 99% by all glufosinate programs and mixtures of glyphosate plus pyrithiobac. Seed cotton yields with glufosinate-based systems were at least 3.3 times greater than yields with glyphosate-based systems because of differences in control of glyphosate-resistant Palmer amaranth. DA - 2009/// PY - 2009/// DO - 10.1614/WT-08-168.1 VL - 23 IS - 3 SP - 356-362 SN - 1550-2740 KW - Crop injury KW - crop tolerance KW - glyphosate-resistant weeds KW - herbicide-resistant cotton ER - TY - JOUR TI - Water conservation potential of smart irrigation controllers on St. Augustinegrass AU - McCready, M. S. AU - Dukes, M. D. AU - Miller, G. L. T2 - AGRICULTURAL WATER MANAGEMENT AB - A variety of technologies for reducing residential irrigation water use are available to homeowners. These “Smart Irrigation” technologies include evapotranspiration (ET)-based controllers and soil moisture sensor (SMS) controllers. The purpose of this research was to evaluate the effectiveness of these technologies, along with rain sensors, based on irrigation applied and turfgrass quality measurements on St. Augustinegrass (Stenotaphrum secundatum (Walter) Kuntze). Testing was performed on two types of SMS controllers (LawnLogic LL1004 and Acclima Digital TDT RS500) at three soil moisture threshold settings. Mini-Clik rain sensors (RS) comprised six treatments at two rainfall thresholds (3 mm and 6 mm) and three different irrigation frequencies (1, 2, and 7 d/wk). Two ET controllers were also tested, the Toro Intelli-Sense controller and the Rain Bird ET Manager. A time-based treatment with 2 days of irrigation per week without any type of sensor (WOS) to bypass irrigation was established as a comparison. All irrigation controller programming represented settings that might be used in residential/commercial landscapes. Even though three of the four testing periods were relatively dry, all of the technologies tested managed to reduce water application compared to the WOS treatment, with most treatments also producing acceptable turf quality. Reductions in irrigation applied were as follows: 7–30% for RS-based treatments, 0–74% for SMS-based treatments, and 25–62% for ET-based treatments. The SMS treatments at low threshold settings resulted in high water savings, but reduced turf quality to unacceptable levels. The medium threshold setting (approximately field capacity) SMS-based treatment produced good turfgrass quality while reducing irrigation water use compared to WOS by 11–53%. ET controllers with comparable settings and good turf quality had −20% to 59% savings. Reducing the irrigation schedule (treatment DWRS) by 40% and using a rain sensor produced water savings between 36% and 53% similar to smart controllers. Proper installation and programming of each of the technologies was essential element to balancing water conservation and acceptable turf quality. Water savings with the SMS controllers could have been increased with a reduced time-based irrigation schedule. Efficiency settings of 100% (DWRS) and 95% (TORO) did not reduce turf quality below acceptable limits and resulted in substantial irrigation savings, indicating that efficiency values need not be low in well designed and maintained irrigation systems. For most conditions in Florida, the DWRS schedule (60% of schedule used for SMS treatments) can be used with either rain sensors or soil moisture sensors in bypass control mode as long as the irrigation system has good coverage and is in good repair. DA - 2009/11// PY - 2009/11// DO - 10.1016/j.agwat.2009.06.007 VL - 96 IS - 11 SP - 1623-1632 SN - 1873-2283 KW - Soil moisture sensor KW - Rain sensor KW - Evapotranspiration controller KW - Turfgrass ER - TY - JOUR TI - Tropical instability wave interactions within the Galapagos Archipelago AU - Sweet, W. V. AU - Morrison, J. M. AU - Liu, Y. AU - Kamykowski, D. AU - Schaeffer, B. A. AU - Xie, L. AU - Banks, S. T2 - DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS AB - Abstract The effects of tropical instability waves (TIW) within the eastern equatorial Pacific during the boreal fall of 2005 were observed in multiple data sets. The TIW cause oscillations of the sea surface temperature (SST), meridional currents ( V ), and 20 °C isotherm (thermocline). A particularly strong 3-wave packet of ∼15-day period TIW passed through the Galapagos Archipelago in Sep and Oct 2005 and their effects were recorded by moored near-surface sensors. Repeat Argo profiles in the archipelago showed that the large temperature (>5 °C) oscillations that occurred were associated with a vertical adjustment within the water column. Numerical simulations report strong oscillations and upwelling magnitudes of ∼5.0 m d −1 near the Tropical Atmosphere Ocean (TAO) buoy at 0°, 95°W and in the Archipelago at 92°W and 90°W. A significant biological response to the TIW passage was observed within the archipelago. Chlorophyll a measured by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) increased by >30% above 1998–2007 mean concentrations within the central archipelago. The increases coincide with coldest temperatures and the much larger increases within the archipelago as compared to those of 95°W indicate that TIW induced upwelling over the island platform itself brought more iron-enriched upwelling waters into the euphotic zone. DA - 2009/8// PY - 2009/8// DO - 10.1016/j.dsr.2009.02.005 VL - 56 IS - 8 SP - 1217-1229 SN - 1879-0119 KW - Tropical instability waves KW - Upwelling KW - Eastern equatorial pacific KW - Galapagos KW - Chlorophyll ER - TY - JOUR TI - Three Experimental Systems to Evaluate Phosphorus Supply from Enhanced Granulated Manure Ash AU - Crozier, C. R. AU - Havlin, J. L. AU - Hoyt, G. D. AU - Rideout, J. W. AU - McDaniel, R. T2 - AGRONOMY JOURNAL AB - Three experimental systems were used to evaluate a new P fertilizer since residual P levels at typical farm sites may make response detection unlikely. The systems were (i) greenhouse with low P soil, (ii) long‐term research sites with preexisting soil P gradients, and (iii) agricultural fields with prior P fertilization based on agronomic recommendations. The new fertilizer (animal waste by‐product, AWP: 5% N, 28% P 2 O 5 , 4% K 2 O, and 1% S) is an enhanced granulated manure ash. Corn ( Zea mays L.), wheat ( Triticum aestivum L.), and soybean [ Glycine max (L.) Merr.] growth, P uptake, and residual soil Mehlich‐3 P were measured with agronomic rates of AWP or triple superphosphate (TSP). Greenhouse corn and wheat P uptake, and soil Mehlich‐3 P increased similarly with either fertilizer at rates equivalent to 0, 10, 20, 40, and 80 kg P ha −1 . In long‐term research sites, grain yield increased with P fertilization in 8 of 12 tests, and was greater with TSP than with AWP in 3 of 12 tests. Plant P uptake increased in all 12 tests, and was greater with TSP in 1 of 12 tests. In previously fertilized agricultural fields, soil Mehlich‐3 P, but not yield, increased due to P fertilization. Fertilizer source differences were infrequent and relatively minor, but possibly due to lower water soluble P content of the AWP (70% versus 78% for TSP). Evaluation of such products requires an appropriate experimental system with low P soils that may be difficult to find on typical North Carolina farms. DA - 2009/// PY - 2009/// DO - 10.2134/agronj2008.0187x VL - 101 IS - 4 SP - 880-888 SN - 0002-1962 ER - TY - JOUR TI - Sorghum sudangrass as a summer cover and hay crop for organic fall cabbage production AU - Finney, Denise M. AU - Creamer, Nancy G. AU - Schultheis, Jonathan R. AU - Wagger, Michael G. AU - Brownie, Cavell T2 - RENEWABLE AGRICULTURE AND FOOD SYSTEMS AB - Abstract No-tillage (NT) organic vegetable production presents several economic opportunities for growers in the southeastern United States while promoting natural resource conservation. This study was conducted to determine if removal of sorghum sudangrass (SS) cover crop biomass as hay, frequency at which the cover crop is mowed, and tillage affect weed suppression and head weight of transplanted organic cabbage. Sorghum sudangrass [ Sorghum bicolor (L.) Moench× Sorgum sudanense (Piper) Staph.] was planted in May 2004 at Reidsville and Goldsboro, NC, preceding the planting of organic ‘Bravo’ cabbage ( Brassica oleracea L. Capitata group) in August and September 2004, respectively. SS management systems included: low-frequency mowing with hay removed following the first mowing operation (LFM-H), low-frequency mowing with hay not removed (LFM), high-frequency mowing with hay not removed (HFM) and a no cover crop control. Two tillage treatments were applied within each management system: conventional tillage (CT) and NT. Under NT conditions, SS mulch generated by LFM offered broadleaf weed control in cabbage similar to that achieved under CT, regardless of whether cover crop biomass was removed as hay. Mowing with higher frequency reduced SS cover crop biomass by 18–33% and reduced weed suppression in NT cabbage. Mowing frequency did not influence the quantity of SS that re-grew in the cabbage crop. SS re-growth contributed to lower head weight in NT compared to CT cabbage in Goldsboro, and crop failure of NT cabbage in Reidsville. Cabbage head weight was highest when the crop was not preceded by SS in both CT and NT systems (1.6 as opposed to 1.3–1.4 kg head −1 ). Our findings suggest that the potential for growers to manage a cover crop also as a hay crop does exist; however, SS may not be a compatible cover crop species for organic fall cabbage production due to high amounts of re-growth. DA - 2009/9// PY - 2009/9// DO - 10.1017/S174217050999007X VL - 24 IS - 3 SP - 225-233 SN - 1742-1713 KW - Sorghum bicolor x Sorghum sudanense KW - Brassica oleracea KW - no-tillage KW - conservation tillage KW - organic vegetable production KW - cover cropping KW - weed management ER - TY - JOUR TI - Soil Organic Matter Changes in Turfgrass Systems Affect Binding and Biodegradation of Simazine AU - Hixson, Adam C. AU - Shi, Wei AU - Weber, Jerome B. AU - Yelverton, Fred H. AU - Rufty, Thomas W. T2 - CROP SCIENCE AB - Concern about pesticide losses from maintained turfgrass areas led us to examine the fate of the triazine herbicide simazine in turfgrass systems and, specifically, interactions between simazine binding to soil organic matter and biodegradation. Soil samples were removed from turfgrass systems of different ages, placed in microcosms, conditioned as sterile or nonsterile, and exposed to 14 C‐simazine. At seven sampling intervals, the soil was extracted and 14 C was separated into three pools; bound, extractable, and CO 2 With sterilized surface soil (0–5 cm), 52, 70, and 71% of applied 14 C‐simazine was bound to soil from the 4‐, 21‐, and 99‐yr‐old turfgrass systems, respectively, after 16 wk. With nonsterile conditions, biodegradation became dominant, as 60 to 80% of the 14 C was recovered in the CO 2 fraction and binding was held at ∼20%. Among all soils evaluated, bound 14 C and 14 CO 2 production was lower in subsurface soil (5–15 cm) from the 4‐ and 21‐yr‐old turfgrass systems. 14 C‐simazine disappearance time (DT 50 ) values under nonsterile conditions ranged from 0.9 to 5.8 wk. Results indicate that turfgrass systems have a relatively low amount of simazine available for leaching as the systems age due to a large capacity for biodegradation and binding to organic matter. DA - 2009/// PY - 2009/// DO - 10.2135/cropsci2008.09.0541 VL - 49 IS - 4 SP - 1481-1488 SN - 0011-183X ER - TY - JOUR TI - Sequential Applications for Mesosulfuron and Nitrogen Needed in Wheat AU - Sosnoskie, Lynn M. AU - Culpepper, A. Stanley AU - York, Alan C. AU - Beam, Josh B. AU - MacRae, Andrew W. T2 - WEED TECHNOLOGY AB - Mesosulfuron is often applied to wheat at a time of year when top-dress nitrogen is also applied. Current labeling for mesosulfuron cautions against applying nitrogen within 14 d of herbicide application. Soft red winter wheat response to mesosulfuron and urea ammonium nitrate (UAN) applied sequentially and in mixtures was determined at three locations in North Carolina and Georgia during 2005 and 2006. Mesosulfuron at 0, 15, and 30 g ai/ha was applied in water to wheat at Feekes growth stage (GS) 3 followed by UAN at 280 L/ha 2 h, 7 d, 14 d, and 21 d after mesosulfuron. Mesosulfuron applied in UAN was also evaluated in 2006. Mesosulfuron injured wheat 6 to 9% in 2005 and 12 to 23% in 2006 when UAN was applied 2 h or 7 d after the herbicide. Wheat injury did not exceed 8% when UAN was applied 14 or 21 d after the herbicide. Greatest injury, 35 to 40%, was noted when mesosulfuron and UAN were combined. Wheat yield was unaffected by mesosulfuron or time of UAN application in 2005. In 2006, yield was affected by the timing of UAN application relative to mesosulfuron; wheat yield increased as the interval, in days, between UAN and herbicide applications increased. To avoid crop injury and possible yield reduction, mesosulfuron and UAN applications should be separated by at least 7 to 14 d. These findings are consistent with precautions on the mesosulfuron label. DA - 2009/// PY - 2009/// DO - 10.1614/WT-09-019.1 VL - 23 IS - 3 SP - 404-407 SN - 1550-2740 KW - Crop injury KW - herbicide-fertilizer interaction KW - herbicide and fertilizer mixtures KW - nitrogen carrier for herbicide KW - urea ammonium nitrate ER - TY - JOUR TI - Identification and Mapping of New Sources of Resistance to Aflatoxin Accumulation in Maize AU - Warburton, Marilyn L. AU - Brooks, Thomas. D. AU - Krakowsky, Matthew D. AU - Shan, Xueyan AU - Windham, Gary L. AU - Williams, W. Paul T2 - CROP SCIENCE AB - Maize ( Zea mays L.) susceptibility to ear rot and aflatoxin accumulation by Aspergillus flavus (Link:Fr) has caused significant economic losses for farmers in the U.S. over the past 30 years. Aflatoxin outbreaks are generally associated with high temperatures and low moisture levels common to the southern U.S. To identify aflatoxin accumulation resistance quantitative trait loci (QTL) and linked markers for marker‐assisted breeding (MAB), a genetic mapping population of F 2:3 family genotypes, increased by sib‐mating, was developed from Mp717, a maize inbred resistant to aflatoxin accumulation, and NC300, a southern‐adapted inbred with low levels of resistance and desirable agronomic traits. Replicated trials of the mapping population were subjected to A. flavus inoculation in Tifton, GA and Starkville, MS in 2004 and 2005. Quantitative trait loci on all chromosomes, except chromosomes 4, 6, and 9, were identified, and individual QTL explained from less than 1% to a maximum of 11% of the phenotypic variance in aflatoxin accumulation in grain. Both Mp717 and NC300 were found to contribute resistance to aflatoxin accumulation in the F 2:3 families and overall QTL effects differed because of environmental conditions. Many of these loci were distinct from previously identified QTL, which confirmed Mp717 as a novel source of aflatoxin resistance. DA - 2009/// PY - 2009/// DO - 10.2135/cropsci2008.12.0696 VL - 49 IS - 4 SP - 1403-1408 SN - 1435-0653 ER - TY - JOUR TI - Growth and reproductive performance of beef heifers grazing endophyte-free, endophyte-infected and novel endophyte-infected tall fescue AU - Drewnoski, M. E. AU - Oliphant, E. J. AU - Poore, M. H. AU - Green, J. T. AU - Hockett, M. E. T2 - Livestock Science AB - A three-year study was conducted to investigate the effects of endophyte-free (E−), endophyte-infected (E+) and novel endophyte-infected (EN) tall fescue on the growth and pregnancy rate of beef heifers during the spring. Each year, 48 beef heifers were strip-grazed on stockpiled fescue from December through February, fed fescue hay during late February to early April and then rotationally grazed on spring growth of fescue until June. At the end of the trial, heifers had been maintained on E+, E− or EN (pasture or hay) for a total of 152, 188 and 191 d in years 1, 2, and 3, respectively. In late March, heifers were synchronized using a controlled intravaginal drug-releasing device, (CIDR®) for 7 d followed by injection with PGF2α (Lutalyse®). Heatmount detectors (Kamar®) and observation for behavioral estrus were used to detect estrus for 63 d. Heifers were artificially inseminated 8 to12 h after the onset of standing estrus. Conception was determined by transrectal ultrasonography at approximately 30, 60 and 90 d after synchronization. Reproductive performance did not differ among treatments (P ≥ 0.20). Pregnancy rate was 54, 65, and 65% for E+, E− and EN, respectively. However, during the spring, growth and prolactin were decreased (P < 0.01) for heifers on E+. Gains on spring pasture were 0.24, 0.75, and 0.71 kg/d (SEM ± 0.03) for E+, E− and EN, respectively. Based on these results, the wild type endophyte-infected fescue can be used in production systems as a source of winter forage but producers should consider placing heifers on alternative forage (such as the novel endophyte-infected fescue) in the spring. DA - 2009/// PY - 2009/// DO - 10.1016/j.livsci.2009.05.003 VL - 125 IS - 2-3 SP - 254-260 ER - TY - JOUR TI - Effects of Preplant and Postplant Rotary Hoe Use on Weed Control, Soybean Pod Position, and Soybean Yield AU - Place, George T. AU - Reberg-Horton, S. Chris AU - Burton, Michael G. T2 - WEED SCIENCE AB - Demand for organic food products has consistently increased for more than 20 yr. The largest obstacle to organic soybean production in the southeastern United States is weed management. Current organic soybean production relies on mechanical weed control, including multiple postplant rotary hoe uses. Although postplant rotary hoe use is effective at the weed germination stage, its efficacy is severely compromised by delays due to weather. Preplant rotary hoeing is also a practice that has been utilized for weed control but the effectiveness of this practice to reduce the need for multiple postplant rotary hoeing for organic soybean production in the southeastern United States has not been investigated. Preplant rotary hoe treatments included a weekly rotary hoeing 4 wk before planting, 2 wk before planting, and none. Postplant rotary hoe treatments consisted of zero, one, two, three, and four postplant rotary hoe uses. Weed control was increased with preplant rotary hoeing at Plymouth in 2006 and 2007 but this effect disappeared with the first postplant rotary hoeing. Multiple postplant rotary hoe uses decreased soybean plant populations, decreased soybean canopy height, lowered soybean pod position, and decreased soybean yield. Plant mapping revealed that the percentage of total nodes and pods below 30 cm was increased by increased frequency of postplant rotary hoe use. DA - 2009/// PY - 2009/// DO - 10.1614/WS-08-132.1 VL - 57 IS - 3 SP - 290-295 SN - 1550-2759 KW - Organic weed management KW - organic farming KW - stale seedbed KW - mechanical weed control ER - TY - JOUR TI - Effectiveness of an Innovative Prototype Subtracted Diversity Array (SDA) for Fingerprinting Plant Species of Medicinal Importance AU - Jayasinghe, Ruchira AU - Niu, Lin Hai AU - Coram, Tristan E. AU - Kong, Stephan AU - Kaganovitch, Janna AU - Xue, Charlie C. L. AU - Li, Chun G. AU - Pang, Edwin C. K. T2 - PLANTA MEDICA AB - The accurate identification of medicinal plants is becoming increasingly important due to reported concerns about purity, quality and safety. The previously developed prototype subtracted diversity array (SDA) had been validated for the ability to distinguish clade-level targets in a phylogenetically accurate manner. This study represents the rigorous investigation of the SDA for genotyping capabilities, including the genotyping of plant species not included during the construction of the SDA, as well as to lower classification levels including family and species. The results show that the SDA, in its current form, has the ability to accurately genotype species not included during SDA development to clade level. Additionally, for those species that were included during SDA development, genotyping is successful to the family level, and to the species level with minor exceptions. Twenty polymorphic SDA features were sequenced in a first attempt to characterize the polymorphic DNA between species, which showed that transposon-like sequences may be valuable as polymorphic features to differentiate angiosperm families and species. Future refinements of the SDA to allow more sensitive genotyping are discussed with the overall goal of accurate medicinal plant identification in mind. DA - 2009/8// PY - 2009/8// DO - 10.1055/s-0029-1185484 VL - 75 IS - 10 SP - 1180-1185 SN - 1439-0221 KW - genotyping KW - microarray KW - diversity KW - phylogenetics KW - angiosperms ER - TY - JOUR TI - Correlation between Temperature and Oleic Acid Seed Content in Three Segregating Soybean Populations AU - Bachlava, Eleni AU - Cardinal, Andrea J. T2 - CROP SCIENCE AB - The development of high‐oleate soybean [ Glycine max (L.) Merr.] germplasm, currently in demand due to its nutritional value and oxidative stability, may be hampered by the instability of fatty acid composition across environments, which is largely attributed to temperature changes and its effects on fatty acid biosynthesis during the period of oil deposition. In the present study, we evaluated three soybean populations that segregated for oleate content and maturity at multiple environments in North Carolina. Oleate content was positively correlated with daily temperatures, averaged over the seed‐filling stage, for the experimental lines of the late‐maturing population but was negatively correlated for the lines of the early‐maturing populations. Oil content was positively correlated with the average daily temperature during seed filling in all three populations, regardless of their early‐ or late‐maturity profile. Negative correlations between oleate content and temperature during the period of oil deposition have not been previously reported. Moreover, in contrast to previous reports, maximum, minimum, and average daily temperatures were highly correlated during seed filling in all environments of this study. We conclude that cautious interpretation of these findings is necessary due to the correlation between temperature and photoperiod during the period of oil deposition. DA - 2009/// PY - 2009/// DO - 10.2135/cropsci2008.11.0660 VL - 49 IS - 4 SP - 1328-1335 SN - 1435-0653 ER - TY - JOUR TI - Characterization of eversion syndrome in captive Scyphomedusa jellyfish AU - Freeman, Kate S. AU - Lewbart, Gregory A. AU - Robarge, Wayne P. AU - Harms, Craig A. AU - Law, J. Mchugh AU - Stoskopf, Michael K. T2 - AMERICAN JOURNAL OF VETERINARY RESEARCH AB - Abstract Objective —To determine whether Scyphomedusa jellyfish with eversion syndrome had alterations in husbandry conditions, elemental content, or histologic appearance, compared with unaffected jellyfish. Animals —123 jellyfish (44 with eversion syndrome and 79 without) at 6 institutions. Procedures —Elemental analyses were performed on 24 jellyfish with eversion syndrome and 49 without, and histologic examinations were performed on 20 jellyfish with eversion syndrome and 30 without. A questionnaire distributed to 39 institutions with Scyphomedusa jellyfish was used to gather information about husbandry, environmental conditions, and prevalence of eversion syndrome. Results —For the 39 institutions that responded to the questionnaire, prevalence of eversion syndrome ranged from 0% to 30%. For Aurelia aurita , eversion was more common at institutions with only captive-raised and no wild-caught jellyfish. Eversion was most common among young (approx 1- to 2-month-old) growing jellyfish and older (> 6-month-old) jellyfish. Elemental analysis revealed only minor differences between affected and unaffected jellyfish, with great variation among jellyfish from the same institution and among jellyfish from different institutions. Striated muscle degeneration and necrosis and extracellular matrix (mesoglea) degeneration were evident on histologic examination of affected jellyfish. Conclusions and Clinical Relevance —Results suggested that eversion syndrome is a complex phenomenon associated with degenerative changes of the bell matrix. DA - 2009/9// PY - 2009/9// DO - 10.2460/ajvr.70.9.1087 VL - 70 IS - 9 SP - 1087-1093 SN - 0002-9645 ER - TY - JOUR TI - Asymmetric Responses of Paspalum Species to a Soil Moisture Gradient AU - Henry, Gerald M. AU - Yelverton, Fred H. AU - Burton, Michael G. T2 - CROP SCIENCE AB - Anecdotal evidence suggests that dallisgrass ( Paspalum dilatatum Poir.) and bahiagrass ( Paspalum notatum Flueggé), two of the most troublesome weed species in managed turfgrass, are both drought and flood tolerant. Water table depth gradient tanks were employed to identify habitat specialization and competitive differences between dallisgrass and bahiagrass. Shoot and rhizome final biomass and survival were used as metrics for plants grown in monoculture or competition with hybrid bermudagrass ( Cynodon transvaalensis Burtt Davy × C. dactylon (L.) Pers. ‘Tifway 419’) in sand or sandy loam soil. Shoot and rhizome growth of dallisgrass was greatest at the levels of highest soil moisture within each gradient tank regardless of soil type or competition. Percent survival of dallisgrass decreased to a low of 50% as depth to water table increased when grown as a monoculture and 12.5% when grown in competition with hybrid bermudagrass. Percent survival of bahiagrass was 100% regardless of water table depth, soil type, or competition. Shoot and rhizome growth of bahiagrass was greatest as depth to water table increased when grown in sandy loam soil. The opposite trend was observed when grown in sandy soil. Results suggest that dallisgrass may be more competitive with hybrid bermudagrass when volumetric soil moisture is high, while bahiagrass may be more competitive when volumetric soil moisture is low. DA - 2009/// PY - 2009/// DO - 10.2135/cropsci2008.08.0506 VL - 49 IS - 4 SP - 1473-1480 SN - 0011-183X ER - TY - JOUR TI - A technique for assessing environmental impact risks of agricultural systems AU - Sydorovych, Olha AU - Raczkowski, Charles W. AU - Wossink, Ada AU - Mueller, J. Paul AU - Creamer, Nancy G. AU - Hu, Shuijin AU - Bell, Melissa AU - Tu, Cong T2 - RENEWABLE AGRICULTURE AND FOOD SYSTEMS AB - Abstract Conventional agriculture often aims to achieve high returns without allowing for sustainable natural resource management. To prevent environmental degradation, agricultural systems must be assessed and environmental standards need to be developed. This study used a multi-factor approach to assess the potential environmental impact risk of six diverse systems: five production systems and a successional system or abandoned agronomic field. Assessment factors were soil quality status, amount of pesticide and fertilizer applied and tillage intensity. The assessment identified the best management practices (BMP)–conventional tillage system as a high-risk system mostly because of extensive tillage. The certified organic system was also extensively tilled and was characterized by P build-up in the soil, but performed well based on other assessment factors. Conversely, the BMP–no tillage and the crop–animal integrated system were characterized as low risk mainly because of reduced tillage. The paper discusses assessment strengths and weaknesses, ways to improve indicators used, and the need for additional indicators. We concluded that with further development the technique will become a resourceful tool to promote agricultural sustainability and environmental stewardship and assist policy-making processes. DA - 2009/9// PY - 2009/9// DO - 10.1017/S174217050999010X VL - 24 IS - 3 SP - 234-243 SN - 1742-1713 KW - environmental impact assessment KW - environmental risk indicators KW - agricultural production systems KW - soil quality KW - large-scale systems experiment KW - best management practices KW - farming systems ER - TY - JOUR TI - Status of the USA cotton germplasm collection and crop vulnerability AU - Wallace, T. P. AU - Bowman, D. AU - Campbell, B. T. AU - Chee, P. AU - Gutierrez, O. A. AU - Kohel, R. J. AU - McCarty, J. AU - Myers, G. AU - Percy, R. AU - Robinson, F. AU - Smith, W. AU - Stelly, D. M. AU - Stewart, J. M. AU - Thaxton, P. AU - Ulloa, M. AU - Weaver, D. B. T2 - GENETIC RESOURCES AND CROP EVOLUTION DA - 2009/6// PY - 2009/6// DO - 10.1007/s10722-008-9382-2 VL - 56 IS - 4 SP - 507-532 SN - 1573-5109 KW - Cotton KW - Crop vulnerability KW - Germplasm collection and evaluation KW - Gossypium KW - National plant germplasm system KW - Taxonomy ER - TY - JOUR TI - Robustness of risk maps and survey networks to knowledge gaps about a new invasive pest AU - Smith, W. D. T2 - Risk Analysis DA - 2009/// PY - 2009/// ER - TY - JOUR TI - Registration of 'N8101' Small-Seeded Soybean AU - Carter, T. E., Jr. AU - Burton, J. W. AU - Rzewnicki, P. E. AU - Villagarcia, M. R. AU - Fountain, M. O. AU - Bowman, D. T. AU - Taliercio, Earl T2 - JOURNAL OF PLANT REGISTRATIONS AB - ‘N8101’ soybean [ Glycine max (L.) Merr.] (Reg. No. CV‐498, PI 654355) was cooperatively developed and released by the USDA‐ARS and the North Carolina Agricultural Research Service in February 2008 as a small‐seeded Maturity Group VIII conventional cultivar. N8101 is the first publicly released small‐seeded soybean cultivar in its maturity group and has potential use in the Japanese soyfoods market. It was derived from the cross of small‐seeded germplasm NC114 and a small‐seeded cultivar N7101. N8101 is adapted to the southeastern United States between 30 and 36° N latitude. In 22 USDA regional trials, N8101 exhibited a 100‐seed weight of 7.3 g, 5.4 g less than that of control variety, ‘Prichard RR’. Yield of N8101 was approximately 92% of that produced by Prichard RR (2712 kg ha −1 ). Over seven additional trials in North Carolina, N8101 had a 100‐seed weight of 6.5 g, 1.4 g less than that of small‐seeded Maturity Group VII cultivar N7103. Seed protein content was similar to that of Prichard RR, and seed carbohydrate composition was similar to that of N7103. N8101 is resistant to shattering, Soybean mosaic virus , frogeye leaf spot ( Cercospora sojina Hara), and bacterial pustule [ Xanthomonas campestris pv. glycines (Nakano) Dye]. The reduced yield of N8101 compared with commodity‐type cultivars limits its use to specialty purposes. DA - 2009/1// PY - 2009/1// DO - 10.3198/jpr2008.05.0259crc VL - 3 IS - 1 SP - 22-27 SN - 1940-3496 ER - TY - JOUR TI - German Cockroach Allergen Levels in North Carolina Schools: Comparison of Integrated Pest Management and Conventional Cockroach Control AU - Nalyanya, Godfrey AU - Gore, J. Chad AU - Linker, H. Michael AU - Schal, Coby T2 - JOURNAL OF MEDICAL ENTOMOLOGY AB - Cockroach suppression is fundamental to cockroach allergen mitigation in infested homes. The effects of various cockroach control strategies on cockroach populations and allergen concentration have not been examined in schools. This study was conducted to compare the effectiveness of integrated pest management (IPM) and conventional pest control in controlling German cockroach (Blattella germanica L.) infestations and concentrations of the cockroach allergen Bla g 1 in public school buildings. Two school districts included six schools that used conventional pest control and one district included seven schools that used IPM to control pests. Cockroach traps were deployed to assess the level of infestation, settled dust samples were collected in food service areas, classrooms, and other school areas, and the Bla g 1 allergen was quantified by ELISA. Both cockroach counts and Bla g 1 concentrations were dependent on the pest control approach, with highly significant differences between IPM-treated schools and conventionally treated schools in both the cockroach mean trap counts (0 versus 82.6 +/- 17.3 cockroaches/trap/wk, respectively) and in the amount of Bla g 1 in dust samples (2.8 +/- 0.3 versus 30.6 +/- 3.4 U/g dust). Cockroaches and Bla g 1 were primarily associated with food preparation and food service areas and much less with classrooms and offices. Our data extend recent findings from studies in homes, showing that cockroach allergens can be reduced by cockroach elimination alone or by integrating several tactics including education, cleaning, and pest control. IPM is not only effective at controlling cockroaches but also can lead to long-term reductions in cockroach allergen concentrations, resulting in a healthier environment for students and school personnel. DA - 2009/5// PY - 2009/5// DO - 10.1603/033.046.0302 VL - 46 IS - 3 SP - 420-427 SN - 1938-2928 KW - cockroaches KW - cockroach allergen KW - Bla g.1 KW - integrated pest management KW - schools ER - TY - JOUR TI - Gene-specific markers for the wheat gene Lr34/Yr18/Pm38 which confers resistance to multiple fungal pathogens AU - Lagudah, Evans S. AU - Krattinger, Simon G. AU - Herrera-Foessel, Sybil AU - Singh, Ravi P. AU - Huerta-Espino, Julio AU - Spielmeyer, Wolfgang AU - Brown-Guedira, Gina AU - Selter, Liselotte L. AU - Keller, Beat T2 - THEORETICAL AND APPLIED GENETICS AB - The locus Lr34/Yr18/Pm38 confers partial and durable resistance against the devastating fungal pathogens leaf rust, stripe rust, and powdery mildew. In previous studies, this broad-spectrum resistance was shown to be controlled by a single gene which encodes a putative ATP-binding cassette transporter. Alleles of resistant and susceptible cultivars differed by only three sequence polymorphisms and the same resistance haplotype was found in the three independent breeding lineages of Lr34/Yr18/Pm38. Hence, we used these conserved sequence polymorphisms as templates to develop diagnostic molecular markers that will assist selection for durable multi-pathogen resistance in breeding programs. Five allele-specific markers (cssfr1-cssfr5) were developed based on a 3 bp deletion in exon 11 of the Lr34-gene, and one marker (cssfr6) was derived from a single nucleotide polymorphism in exon 12. Validation of reference genotypes, well characterized for the presence or absence of the Lr34/Yr18/Pm38 resistance locus, demonstrated perfect diagnostic values for the newly developed markers. By testing the new markers on a larger set of wheat cultivars, a third Lr34 haplotype, not described so far, was discovered in some European winter wheat and spelt material. Some cultivars with uncertain Lr34 status were re-assessed using the newly derived markers. Unambiguous identification of the Lr34 gene aided by the new markers has revealed that some wheat cultivars incorrectly postulated as having Lr34 may possess as yet uncharacterised loci for adult plant leaf and stripe rust resistance. DA - 2009/9// PY - 2009/9// DO - 10.1007/s00122-009-1097-z VL - 119 IS - 5 SP - 889-898 SN - 1432-2242 ER - TY - JOUR TI - Estimating Genetic Coefficients for the CSM-CERES-Maize Model in North Carolina Environments AU - Yang, Zhengyu AU - Wilkerson, Gail G. AU - Buol, Gregory S. AU - Bowman, Daryl T. AU - Heiniger, Ronnie W. T2 - AGRONOMY JOURNAL AB - CSM‐CERES‐Maize has been extensively used worldwide to simulate corn growth and grain production, but has not been evaluated for use in North Carolina. The objectives of this study were to calibrate CSM‐CERES‐Maize soil parameters and genetic coefficients using official variety trial data, evaluate model performance in North Carolina, and determine the suitability of the fitting technique using variety trial data for model calibration. The study used yield data for 53 maize genotypes collected from multiple locations over a 10‐yr period. A stepwise calibration procedure was utilized: (i) two genetic coefficients which determine anthesis and physiological maturity dates were adjusted based on growing degree day requirements for each hybrid; and (ii) plant available soil water and rooting profile were adjusted iteratively with two other genetic coefficients affecting yield. Cross validation was used to evaluate the suitability of this approach for estimating soil and genetic coefficients. The root mean squared errors of prediction (RMSEPs) were similar to fitting errors. Results indicate that CSM‐CERES‐Maize can be used in North Carolina to simulate corn growth under nonlimiting N conditions and variety trial data can be used for estimating genetic coefficients. Hybrid average simulated yields matched measured yields well across a wide range of environments, and simulated hybrid yield rankings were in close agreement with rankings based on measured yields. Data from several site‐years could not be used in fitting genetic coefficients due to large root mean squared errors. In some cases, this could be attributed to a weather event, such as a late‐season hurricane. DA - 2009/// PY - 2009/// DO - 10.2134/agronj2008.0234x VL - 101 IS - 5 SP - 1276-1285 SN - 1435-0645 ER - TY - JOUR TI - Bioenergy from Coastal bermudagrass receiving subsurface drip irrigation with advance-treated swine wastewater AU - Cantrell, Keri B. AU - Stone, Kenneth C. AU - Hunt, Patrick G. AU - Ro, Kyoung S. AU - Vanotti, Matias B. AU - Burns, Joseph C. T2 - BIORESOURCE TECHNOLOGY AB - Coastal bermudagrass (Cynodon dactylon L.) may be a potentially important source of bio-based energy in the southern US due to its vast acreage. It is often produced as part of a waste management plan with varying nutrient composition and energy characteristics on fields irrigated with livestock wastewater. The objective of this study was to determine the effect of subsurface drip irrigation with treated swine wastewater on both the quantity and quality of bermudagrass bioenergy. The treated wastewater was recycled from an advanced treatment system and used for irrigation of bermudagrass in two crop seasons. The experiment had nine water and drip line spacing treatments arrayed in a randomized complete block-design with four replicates. The bermudagrass was analyzed for calorific and mineral contents. Bermudagrass energy yields for 2004 and 2005 ranged from 127.4 to 251.4MJ ha(-1). Compared to irrigation with commercial nitrogen fertilizer, the least biomass energy density was associated with bermudagrass receiving treated swine wastewater. Yet, in 2004 the wastewater irrigated bermudagrass had greater hay yields leading to greater energy yield per ha. This decrease in energy density of wastewater irrigated bermudagrass was associated with increased concentrations of K, Ca, and Na. After thermal conversion, these compounds are known to remain in the ash portion thereby decreasing the energy density. Nonetheless, the loss of energy density using treated effluent via SDI may be offset by the positive influence of these three elements for their catalytic properties in downstream thermal conversion processes such as promoting a lesser char yield and greater combustible gas formation. DA - 2009/7// PY - 2009/7// DO - 10.1016/j.biortech.2009.01.070 VL - 100 IS - 13 SP - 3285-3292 SN - 0960-8524 KW - Animal manure KW - Manure management KW - Plant nutrients KW - Water resources KW - Thermochemical conversion ER - TY - JOUR TI - XANES Speciation of P in Environmental Samples: An Assessment of Filter Media for on-Site Wastewater Treatment AU - Eveborn, David AU - Gustafsson, Jon Petter AU - Hesterberg, Dean AU - Hillier, Stephen T2 - ENVIRONMENTAL SCIENCE & TECHNOLOGY AB - X-ray absorption near edge structure (XANES) spectroscopy is a useful technique for characterization of chemical species of phosphorus in complex environmental samples. To develop and evaluate bed filters as sustainable on-site wastewater treatment solutions, our objective in this study was to determine the chemical forms of accumulated phosphorus in a selection of promising filter materials: Filtralite P, Filtra P, Polonite, Absol, blast furnace slag, and wollastonite. Full-scale operational wastewater-treatment systems were sampled and in addition, filter samples collected from laboratory studies provided access to additional media and complementary samples. Phosphorus species were characterized using phosphorus K-edge XANES spectroscopy, complemented by X-ray powder diffraction (XRPD) and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR). No systematic differences could be seen in the results between laboratory- and full-scale samples. All six filter media contained significant amounts of crystalline calcium phosphates. Some samples also contained amorphous calcium phosphate (>60% of total P in Absol). In Filtralite P and blast furnace slag, more than 35% of the accumulated phosphorus was associated with Fe or Al. Both the power and shortcomings of XANES analysis for characterizing P species in these filter media are discussed. DA - 2009/9/1/ PY - 2009/9/1/ DO - 10.1021/es901084z VL - 43 IS - 17 SP - 6515-6521 SN - 0013-936X UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-69549090592&partnerID=MN8TOARS ER - TY - JOUR TI - Weed Management Using Reduced Rate Combinations of Diclosulam, Flumioxazin, and Imazapic in Peanut AU - Ducar, J. Tredaway AU - Clewis, S. B. AU - Wilcut, J. W. AU - Jordan, D. L. AU - Brecke, B. J. AU - Grichar, W. J. AU - Johnson, W. C., III AU - Wehtje, G. R. T2 - WEED TECHNOLOGY AB - Experiments were conducted during 2000 and 2001 at a total of 13 locations throughout Alabama, Georgia, Florida, North Carolina, and Texas to evaluate efficacy of herbicides at or below the manufacturer's suggested use rate. Herbicide applications included diclosulam and flumioxazin applied PRE alone or followed by imazapic applied early postemergence (EPOST). All possible combinations of diclosulam at 0, 13.5, or 27 g ai/ha and flumioxazin at 0, 53, or 105 g ai/ha applied PRE were included. Imazapic was applied at 35 g ai/ha. Ivyleaf morningglory was controlled more than 87% when imazapic was applied EPOST regardless of PRE herbicide. Pitted morningglory control > 67% was observed with applications of diclosulam (27 g/ha) followed by imazapic, diclosulam (13.5 g/ha) plus flumioxazin (53 g/ha), diclosulam (13.5 g/ha) plus flumioxazin (105 g/ha), and diclosulam (27 g/ha) plus flumioxazin (105 g/ha). Sicklepod was controlled more than 74% with flumioxazin (53 g/ha) followed by imazapic and diclosulam (27 g/ha) plus flumioxazin (105 g/ha) followed by imazapic. Florida beggarweed was controlled more than 84% by all PRE herbicide combinations except flumioxazin (53 g/ha) alone or diclosulam (27 g/ha) alone or with imazapic. Yellow nutsedge was controlled at least 90% with diclosulam at either rate followed by imazapic and by diclosulam plus flumioxazin followed by imazapic regardless of rate. Pod yield was generally higher when herbicides were applied regardless of herbicide combination or rate. Peanut yield was maximized with the lowest rates of flumioxazin or diclosulam PRE followed by imazapic EPOST. DA - 2009/// PY - 2009/// DO - 10.1614/WT-07-180.1 VL - 23 IS - 2 SP - 236-242 SN - 1550-2740 KW - Herbicide rate KW - Florida beggarweed KW - ivyleaf morningglory KW - peanut KW - pitted morningglory KW - sicklepod KW - yellow nutsedge ER - TY - JOUR TI - US Farmer Awareness of Glyphosate-Resistant Weeds and Resistance Management Strategies AU - Johnson, William G. AU - Owen, Micheal D. K. AU - Kruger, Greg R. AU - Young, Bryan G. AU - Shaw, David R. AU - Wilson, Robert G. AU - Wilcut, John W. AU - Jordan, David L. AU - Weller, Stephen C. T2 - WEED TECHNOLOGY AB - A survey of farmers from six U.S. states (Indiana, Illinois, Iowa, Nebraska, Mississippi, and North Carolina) was conducted to assess the farmers' views on glyphosate-resistant (GR) weeds and tactics used to prevent or manage GR weed populations in genetically engineered (GE) GR crops. Only 30% of farmers thought GR weeds were a serious issue. Few farmers thought field tillage and/or using a non-GR crop in rotation with GR crops would be an effective strategy. Most farmers did not recognize the role that the recurrent use of an herbicide plays in evolution of resistance. A substantial number of farmers underestimated the potential for GR weed populations to evolve in an agroecosystem dominated by glyphosate as the weed control tactic. These results indicate there are major challenges that the agriculture and weed science communities must face to implement long-term sustainable GE GR-based cropping systems within the agroecosystem. DA - 2009/// PY - 2009/// DO - 10.1614/WT-08-181.1 VL - 23 IS - 2 SP - 308-312 SN - 1550-2740 KW - Genetically engineered crops KW - glyphosate-resistant crops KW - herbicide resistance KW - perceptions KW - surveys ER - TY - JOUR TI - The major threshability genes soft glume (sog) and tenacious glume (Tg), of diploid and polyploid wheat, trace their origin to independent mutations at non-orthologous loci AU - Sood, Shilpa AU - Kuraparthy, Vasu AU - Bai, Guihua AU - Gill, Bikram S. T2 - THEORETICAL AND APPLIED GENETICS DA - 2009/7// PY - 2009/7// DO - 10.1007/s00122-009-1043-0 VL - 119 IS - 2 SP - 341-351 SN - 1432-2242 ER - TY - JOUR TI - Taking Measure of Biofuel Limits AU - Sinclair, Thomas R. T2 - AMERICAN SCIENTIST DA - 2009/// PY - 2009/// DO - 10.1511/2009.80.1 VL - 97 IS - 5 SP - 400-407 SN - 1545-2786 ER - TY - JOUR TI - Rapid Microwave Processing of Winter Cereals for Histology Allows Identification of Separate Zones of Freezing Injury in the Crown AU - Livingston, D. P., III AU - Tuong, T. D. AU - Haigler, C. H. AU - Avci, U. AU - Tallury, S. P. T2 - Crop Science AB - ABSTRACT In histological studies, microwave processing of tissue considerably shortens the time required to prepare samples for observation under light and electron microscopy. However, plant tissues from different species and different regions of the plant respond differently to microwave processing, making it impossible to use a single protocol for all plant tissue. The crown of winter cereals such as rye ( Secale cereale L.), wheat ( Triticum aestivum L.), barley ( Hordeum vulgare L.), and oats ( Avena sativa L.) is the below‐ground portion of the stem that overwinters. It is composed of numerous types of cells with an organizational pattern that is similar to other grasses. When we used microwave protocols that were developed for other plant tissues, winter cereal crown tissue shattered and crumbled when sectioned. This study reports a procedure developed to process winter cereal crowns for histological observations. Using this microwave protocol, samples were prepared in 1 d as compared to 2 wk using traditional protocols. This enabled many more samples to be processed and allowed us to identify four overlapping zones of response to freezing within the crown. Results of varying time, temperature, and microwave wattage during fixing, dehydrating, and embedding in paraffin are described. High quality sections from the crowns of oat, barley, wheat, and rye indicate that this procedure is valid for all winter cereals. Since crown tissue is similar across all grass species, we predict that the protocol will be useful for other grasses as well. DA - 2009/9// PY - 2009/9// DO - 10.2135/cropsci2009.02.0077 VL - 49 IS - 5 SP - 1837-1842 J2 - Crop Sci. LA - en OP - SN - 0011-183X UR - http://dx.doi.org/10.2135/cropsci2009.02.0077 DB - Crossref ER - TY - JOUR TI - Population Genetic Analysis of an Eastern US Wheat Powdery Mildew Population Reveals Geographic Subdivision and Recent Common Ancestry with UK and Israeli Populations AU - Parks, Ryan AU - Carbone, Ignazio AU - Murphy, J. Paul AU - Cowger, Christina T2 - PHYTOPATHOLOGY AB - The structure of the U.S. wheat powdery mildew population (Blumeria graminis f. sp. tritici) has not been previously investigated, and the global evolutionary history of B. graminis f. sp. tritici is largely unknown. After gathering 141 single-ascosporic B. graminis f. sp. tritici isolates from 10 eastern U.S. locations, 34 isolates from the United Kingdom, and 28 isolates from Israel, we analyzed pathogen population structure using presumptively neutral markers. DNA was extracted from conidia, primers for 12 “housekeeping” genes were designed, and amplicons were examined for polymorphism. Four genes were found to contain a total of 12 single-nucleotide polymorphisms in the U.S. population and were also analyzed in the U.K. and Israeli populations. In total, 25 haplotypes were inferred from the four concatenated genes, with 2 haplotypes comprising over 70% of the U.S. population. Using Hudson's tests and analysis of molecular variance, we found the wheat mildew isolates subdivided into four groups corresponding to distinct regions: the mid-Atlantic United States, the southern United States, the United Kingdom, and Israel. Genotypic diversity was greatest in samples from the United Kingdom, Israel, Virginia, and Kinston, NC. Using rarefaction, a procedure that compensates for differing sample sizes when estimating population richness and diversity, we found that cooler locations with greater conduciveness to regular powdery mildew epidemics had the greatest haplotype richness. Our results suggest that the eastern U.S. B. graminis f. sp. tritici population is young, descended recently from Old World populations with isolation and genetic drift, and is currently subdivided into northern and southern subpopulations. DA - 2009/7// PY - 2009/7// DO - 10.1094/PHYTO-99-7-0840 VL - 99 IS - 7 SP - 840-849 SN - 1943-7684 ER - TY - JOUR TI - Polygenic inheritance of canopy wilting in soybean [Glycine max (L.) Merr.] AU - Charlson, Dirk V. AU - Bhatnagar, Sandeep AU - King, C. Andy AU - Ray, Jeffery D. AU - Sneller, Clay H. AU - Carter, Thomas E., Jr. AU - Purcell, Larry C. T2 - THEORETICAL AND APPLIED GENETICS DA - 2009/8// PY - 2009/8// DO - 10.1007/s00122-009-1068-4 VL - 119 IS - 4 SP - 587-594 SN - 1432-2242 ER - TY - JOUR TI - Peanut and Eclipta (Eclipta prostrata) Response to Flumioxazin AU - Jordan, David L. AU - Lancaster, Sarah H. AU - Lanier, James E. AU - Lassiter, Bridget R. AU - Johnson, P. Dewayne T2 - WEED TECHNOLOGY AB - Research was conducted in North Carolina to determine peanut response to flumioxazin as influenced by rate and timing of application and cultivar. Delaying application of flumioxazin from 1 d after planting until peanut emergence increased injury regardless of rate. The Virginia market-type cultivar ‘NC-V 11’ was injured more by flumioxazin than the cultivars ‘Gregory’ or ‘Perry’. However, pod yield was not affected by flumioxazin even though significant injury was observed early in the season regardless of flumioxazin rate, application timing, or cultivar. Diclosulam was more effective than flumioxazin in controlling eclipta when these herbicides were applied PRE with metolachlor or following pendimethalin PPI. However, control by flumioxazin prevented yield loss when compared with metolachlor alone. DA - 2009/// PY - 2009/// DO - 10.1614/WT-08-050.1 VL - 23 IS - 2 SP - 231-235 SN - 0890-037X KW - Crop injury KW - herbicide KW - peanut tolerance KW - weed management ER - TY - JOUR TI - Large-scale analysis of antisense transcription in wheat using the Affymetrix GeneChip Wheat Genome Array AU - Coram, Tristan E. AU - Settles, Matthew L. AU - Chen, Xianming T2 - BMC GENOMICS AB - Natural antisense transcripts (NATs) are transcripts of the opposite DNA strand to the sense-strand either at the same locus (cis-encoded) or a different locus (trans-encoded). They can affect gene expression at multiple stages including transcription, RNA processing and transport, and translation. NATs give rise to sense-antisense transcript pairs and the number of these identified has escalated greatly with the availability of DNA sequencing resources and public databases. Traditionally, NATs were identified by the alignment of full-length cDNAs or expressed sequence tags to genome sequences, but an alternative method for large-scale detection of sense-antisense transcript pairs involves the use of microarrays. In this study we developed a novel protocol to assay sense- and antisense-strand transcription on the 55 K Affymetrix GeneChip Wheat Genome Array, which is a 3' in vitro transcription (3'IVT) expression array. We selected five different tissue types for assay to enable maximum discovery, and used the 'Chinese Spring' wheat genotype because most of the wheat GeneChip probe sequences were based on its genomic sequence. This study is the first report of using a 3'IVT expression array to discover the expression of natural sense-antisense transcript pairs, and may be considered as proof-of-concept.By using alternative target preparation schemes, both the sense- and antisense-strand derived transcripts were labeled and hybridized to the Wheat GeneChip. Quality assurance verified that successful hybridization did occur in the antisense-strand assay. A stringent threshold for positive hybridization was applied, which resulted in the identification of 110 sense-antisense transcript pairs, as well as 80 potentially antisense-specific transcripts. Strand-specific RT-PCR validated the microarray observations, and showed that antisense transcription is likely to be tissue specific. For the annotated sense-antisense transcript pairs, analysis of the gene ontology terms showed a significant over-representation of transcripts involved in energy production. These included several representations of ATP synthase, photosystem proteins and RUBISCO, which indicated that photosynthesis is likely to be regulated by antisense transcripts.This study demonstrated the novel use of an adapted labeling protocol and a 3'IVT GeneChip array for large-scale identification of antisense transcription in wheat. The results show that antisense transcription is relatively abundant in wheat, and may affect the expression of valuable agronomic phenotypes. Future work should select potentially interesting transcript pairs for further functional characterization to determine biological activity. DA - 2009/5/29/ PY - 2009/5/29/ DO - 10.1186/1471-2164-10-253 VL - 10 SP - SN - 1471-2164 ER - TY - JOUR TI - Interactions between N fertilization, grass clipping addition and pH in turf ecosystems: Implications for soil enzyme activities and organic matter decomposition AU - Yao, Huaiying AU - Bowman, Daniel AU - Rufty, Thomas AU - Shi, Wei T2 - Soil Biology and Biochemistry AB - Turf has been acknowledged as an important ecosystem with potential for soil C sequestration. As a major process dictating soil C storage, organic matter decomposition has received little attention in turf systems. Given that soil enzyme-catalyzed biochemical reactions are the rate limiting steps of organic matter decomposition, we examined the activities of oxidative and hydrolytic soil enzymes and their relations with soluble organic compounds and soil C and N mineralization in two turf chronosequences with contrasting soil pH and in response to N fertilization and grass clipping addition. In comparison with turf ecosystems under acidic soil, phenol oxidase activity was about two-fold greater in turf ecosystems under alkaline soil and positively correlated to about two-fold differences in soluble phenolics and dissolved organic C between alkaline and acidic soils. However, the activities of hydrolytic enzymes including cellulase, chitinase, and glucosidase were lower in alkaline soil. It appears that the high concentration of soluble phenolics inhibited the activities of hydrolytic enzymes that in turn limited the decomposition of dissolved organic C and resulted in its accumulation in alkaline soil. Nitrogen mineralization was comparable between alkaline and acidic soils, but CO2 evolution was about two-fold greater in alkaline soil, possibly due to considerable abiotic carbonate dissolution. We observed that mineral N input at 60 mg N kg−1 soil had very minor negative effects on the activities of both phenol oxidase and hydrolytic enzymes. Grass clipping addition did not affect the activity of phenol oxidase, but increased the activities of soil chitinase, cellulase, glucosidase, and glucosaminidase by up to 20% and also soluble phenolics in soil by about 10%. Our results suggest that soil phenol oxidase might regulate the activities of hydrolytic soil enzymes via its control on soluble phenolics and function as an ‘enzymatic latch’ to hold soil organic C in highly managed turf ecosystems. While soil pH is important to affect phenol oxidase activity and therefore decomposition, management practices, i.e., N fertilization and grass clipping addition may indirectly affect the decomposition through enhancing turfgrass productivity and thus soil C input. DA - 2009/7// PY - 2009/7// DO - 10.1016/j.soilbio.2009.03.020 VL - 41 IS - 7 SP - 1425-1432 J2 - Soil Biology and Biochemistry LA - en OP - SN - 0038-0717 UR - http://dx.doi.org/10.1016/j.soilbio.2009.03.020 DB - Crossref KW - Carbon and N mineralization KW - Soil enzyme activity KW - Phenol oxidase KW - Soil phenolic compounds KW - Nitrogen fertilization KW - Turfgrass ER - TY - JOUR TI - Impact of Heterozygosity and Heterogeneity on Cotton Lint Yield Stability AU - Cole, C. B. AU - Bowman, D. T. AU - Bourland, F. M. AU - Caldwell, W. D. AU - Campbell, B. T. AU - Fraser, D. E. AU - Weaver, D. B. T2 - CROP SCIENCE AB - ABSTRACT In the last 8 yr, cotton ( Gossypium hirsutum L.) growers in North Carolina have experienced variations in the year‐to‐year lint yield averages that range from a 56% increase to a 49% decrease. This variability results in wild fluctuations in income and a desire for more stable yields. Genetic structure may contribute to stability. This study was conducted to determine the impact of heterozygosity and heterogeneity on lint yield stability. Lint yield was observed in 18 environments over 3 yr among four population types that included homozygous lines grown in pure stands, homozygous lines grown in blended stands, hybrids grown in pure stands, and hybrids grown in blended stands. Comparisons were made using trait means, standard deviations, and the coefficients of variation (CVs) calculated over environments. There was no significant difference between lines grown in pure stands and blended lines with respect to yield or stability. Hybrids had a lower CV (were more stable) than homozygous lines. This stability was attributed to the hybrids and blends of hybrids out‐yielding the homozygous lines and blends of homozygous lines in the low‐yielding environments, but having similar yields in the high‐yielding environments. These results do not support growing blends to increase stability or yield; however, growing hybrid cultivars could result in increased yields while reducing variability compared with current production practices. DA - 2009/// PY - 2009/// DO - 10.2135/cropsci2008.08.0450 VL - 49 IS - 5 SP - 1577-1585 SN - 1435-0653 ER - TY - JOUR TI - Genetic properties of the maize nested association mapping population AU - McMullen, M.D. AU - Kresovich, S. AU - Villeda, H.S. AU - Bradbury, P. AU - Li, H. AU - Sun, Q. AU - Flint-Garcia, S. AU - Thornsberry, J. AU - Acharya, C. AU - Bottoms, C. AU - Brown, P. AU - Browne, C. AU - Eller, M. AU - Guill, K. AU - Harjes, C. AU - Kroon, D. AU - Lepak, N. AU - Mitchell, S.E. AU - Peterson, B. AU - Pressoir, G. AU - Romero, S. AU - Rosas, M.O. AU - Salvo, S. AU - Yates, H. AU - Hanson, M. AU - Jones, E. AU - Smith, S. AU - Glaubitz, J.C. AU - Goodman, M. AU - Ware, D. AU - Holland, James AU - Buckler, E.S. T2 - Science AB - Codifying Maize Modifications Maize, one of our most important crop species, has been the target of genetic investigation and experimentation for more than 100 years. Crossing two inbred lines tends to result in “better” offspring, in a process known as heterosis. Attempts to map the genetic loci that control traits important for farming have been made, but few have been successful (see the Perspective by Mackay ). Buckler et al. (p. 714 ) and McMullen et al. (p. 737 ) produced a genomic map of maize that relates recombination to genome structure. Even tremendous adaptations in very diverse species were produced by numerous, small additive steps. Differences in flowering time in maize among inbred lines were not caused by a few genes with large effects, but by the cumulative effects of numerous quantitative trait loci—each of which has only a small impact on the trait. DA - 2009/// PY - 2009/// DO - 10.1126/science.1174320 VL - 325 IS - 5941 SP - 737-740 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-68449094455&partnerID=MN8TOARS ER - TY - JOUR TI - General soil-landscape distribution patterns in buffer zones of different order streams AU - Kang, Shujiang AU - Lin, Henry T2 - GEODERMA AB - Understanding landscape and soil distribution patterns in buffer zones along a stream network in a watershed can improve riparian zone management and the representation of soil-landscape parameters in watershed modeling. We analyzed landscape features and soil properties within a 300-m buffer zone of different order streams in a large agricultural watershed (the East Mahantango Creek Watershed) located in the Ridge and Valley Physiographic Province in Pennsylvania, USA. The mean elevation displays an obvious decreasing trend downstream, and increases gradually with the distance away from the streams. Within the buffer distance of approximately 75 m, buffer zone's mean slope shows a rapid increase regardless of stream order; however, it starts to decrease after 75 m in the 1st to 3rd order stream buffers, but continues to increase in a more gradual manner in the 4th and 5th order stream buffers. Agricultural land area percentage increases by 10–25% from near stream area to about 100 m buffer, and becomes nearly the same in 100–300 m buffer zone. The opposite trend holds for forested land area in all stream buffer zones. The 1st to 2nd order stream buffers have 12–28% greater agricultural land area percentage and 0.45–1 m shallower soil depth than the 3rd to 5th order stream buffers, suggesting that the headwater areas in the study watershed are important in preventing nonpoint source pollution due to the more intensive agricultural land use and potential erosion in headwater catchments. The distributions of soil properties in the buffer zones are consistent with the observed landscape patterns. The top two soil layers (approximately A and B horizons) in the 0–100 m buffer zones of the 1st and 2nd order streams generally display a greater clay content and a higher bulk density, but a lesser organic matter content and a lower available water capacity, than those in the similar buffer zones of the 3rd to 5th order streams. Beyond the 100 m buffer distance and in the third layer of the soil profiles (approximately C horizons), the soil properties examined in all stream buffer zones become less distinguishable. With a few exceptions, soil clay content and bulk density increase with increasing buffer distance (particularly within 0–100 m range), while organic matter content and available water capacity decrease with buffer distance. Such patterns reflect the impacts from the landscape features, fluvial processes, and land use in the Ridge and Valley Physiographic region. The results of this study, though maybe specific to the watershed studied, suggest that soil and landscape distribution patterns along stream networks are helpful to guide riparian zone management and nonpoint source pollution prevention in agricultural watersheds. DA - 2009/7/15/ PY - 2009/7/15/ DO - 10.1016/j.geoderma.2009.04.008 VL - 151 IS - 3-4 SP - 233-240 SN - 1872-6259 KW - Soil-landscape pattern KW - Buffer zone KW - Stream order KW - Agricultural watershed ER - TY - JOUR TI - Future directions for hydropedology: quantifying impacts of global change on land use AU - Vepraskas, M. J. AU - Heitman, J. L. AU - Austin, R. E. T2 - HYDROLOGY AND EARTH SYSTEM SCIENCES AB - Abstract. Hydropedology is well positioned to address contemporary issues resulting from climate change. We propose a six-step process by which digital, field-scale maps will be produced to show where climate change impacts will be greatest for two land uses: a) home sites using septic systems, and b) wetlands. State and federal laws have defined critical water table levels that can be used to determine where septic systems will function well or fail, and where wetlands are likely to occur. Hydrologic models along with historic rainfall and temperature data can be used to compute long records of water table data. However, it is difficult to extrapolate such data across land regions, because too little work has been done to test different ways for doing this reliably. The modeled water table data can be used to define soil drainage classes for individual mapping units, and the drainage classes used to extrapolate the data regionally using existing digital soil survey maps. Estimates of changes in precipitation and temperature can also be input into the models to compute changes to water table levels and drainage classes. To do this effectively, more work needs to be done on developing daily climate files from the monthly climate change predictions. Technology currently exists to use the NRCS Soil Survey Geographic (SSURGO) Database with hydrologic model predictions to develop maps within a GIS that show climate change impacts on septic system performance and wetland boundaries. By using these maps, planners will have the option to scale back development in sensitive areas, or simply monitor the water quality of these areas for pathogenic organisms. The calibrated models and prediction maps should be useful throughout the Coastal Plain region. Similar work for other climate-change and land-use issues can be a valuable contribution from hydropedologists. DA - 2009/// PY - 2009/// DO - 10.5194/hess-13-1427-2009 VL - 13 IS - 8 SP - 1427-1438 SN - 1607-7938 ER - TY - JOUR TI - Fructan and its relationship to abiotic stress tolerance in plants AU - Livingston, David P., III AU - Hincha, Dirk K. AU - Heyer, Arnd G. T2 - CELLULAR AND MOLECULAR LIFE SCIENCES AB - Numerous studies have been published that attempted to correlate fructan concentrations with freezing and drought tolerance. Studies investigating the effect of fructan on liposomes indicated that a direct interaction between membranes and fructan was possible. This new area of research began to move fructan and its association with stress beyond mere correlation by confirming that fructan has the capacity to stabilize membranes during drying by inserting at least part of the polysaccharide into the lipid headgroup region of the membrane. This helps prevent leakage when water is removed from the system either during freezing or drought. When plants were transformed with the ability to synthesize fructan, a concomitant increase in drought and/or freezing tolerance was confirmed. These experiments indicate that besides an indirect effect of supplying tissues with hexose sugars, fructan has a direct protective effect that can be demonstrated by both model systems and genetic transformation. DA - 2009/7// PY - 2009/7// DO - 10.1007/s00018-009-0002-x VL - 66 IS - 13 SP - 2007-2023 SN - 1420-9071 KW - Inulin KW - Levan KW - Cold acclimation KW - Subzero acclimation KW - Model systems KW - Liposomes KW - Membrane stabilization KW - Sugar glasses KW - Lipid phase transitions KW - Plant transformation ER - TY - JOUR TI - Environmental Effects on Oleic Acid in Soybean Seed Oil of Plant Introductions with Elevated Oleic Concentration AU - Lee, Jeong-Dong AU - Woolard, Melissa AU - Sleper, David A. AU - Smith, James R. AU - Pantalone, Vincent R. AU - Nyinyi, Catherine N. AU - Cardinal, Andrea AU - Shannon, J. Grover T2 - CROP SCIENCE AB - ABSTRACT Soybean [ Glycine max (L.) Merr.] oil with oleic acid (18:1) content >500 g kg −1 is desirable for a broader role in food and industrial uses. Seed oil in commercially grown soybean genotypes averages about 230 g kg −1 oleic acid. Some maturity group (MG) II to V plant introductions (PIs) have elevated oleic concentrations of 300 to 500 g kg −1 Temperature of the growing environment during the reproductive growth stage affects oleic concentration in soybean oil. The objective of this study was to evaluate stability of oleic acid content among 15 PIs with elevated 18:1 and three checks grown in 16 environments. Oleic acid concentration of the high 18:1 checks N98‐4445A and M23 ranged from 383 to 694 g kg −1 and 428 to 572 g kg −1 with averages of 575 g kg −1 and 508 g kg −1 , respectively. The PIs with the highest 18:1 were MG II to III, with most lines averaging >400 g kg −1 oleic acid concentration over 16 environments. Generally, PIs in MG II to III were less stable across environments than those in MG V. However, MG III PI 379559D ranged from 381 to 513 g kg −1 with an average 439 g kg −1 oleic acid concentration and was the most stable in oleic acid content of the 15 PIs studied. PI379559D was more stable than N98‐4445A or M23. PI417360 and PI506852 averaged highest in 18:1 (>330 g kg −1 ) among MG V PIs studied. Combining genes from these PIs and other sources with elevated 18:1 may be useful in developing higher oleic acid soybean genotypes. DA - 2009/// PY - 2009/// DO - 10.2135/cropsci2008.11.0663 VL - 49 IS - 5 SP - 1762-1768 SN - 1435-0653 ER - TY - JOUR TI - Elevated Atmospheric Carbon Dioxide and O-3 Differentially Alter Nitrogen Acquisition in Peanut AU - Tu, Cong AU - Booker, Fitzgerald L. AU - Burkey, Kent O. AU - Hu, Shuijin T2 - CROP SCIENCE AB - ABSTRACT Elevated atmospheric CO 2 and ozone (O 3 ) may affect productivity of legumes in part by altering symbiotic N 2 fixation. To investigate this possibility, measurements of plant biomass, N levels and natural 15 N abundance (δ 15 N) were used to examine the effects of elevated CO 2 and O 3 on N acquisition in field‐grown peanut ( Arachis hypogaea L.) using open‐top chambers. Seasonal 12‐h daily average CO 2 treatment concentrations were 376, 550, and 730 μmol mol −1 Carbon dioxide treatments were applied in reciprocal combinations with seasonal 12‐h daily average O 3 concentrations of 21, 49, and 79 nmol mol −1 At mid‐vegetative growth, elevated CO 2 significantly reduced leaf N concentrations by up to 44%, but not δ 15 N values. Elevated O 3 did not significantly affect N concentrations or δ 15 N values. At harvest, plant N concentrations were similar among treatments except for a 14% reduction in the highest‐level CO 2 –O 3 treatment. Plant N accumulation varied in proportion with treatment effects on biomass production, which was increased with elevated CO 2 when averaged over the O 3 treatments and suppressed by high‐level O 3 at ambient CO 2 Elevated CO 2 reduced plant δ 15 N values in low‐ and mid‐level O 3 treatments while mid‐ and high‐level O 3 increased them at ambient CO 2 The changes in δ 15 N values suggested that N 2 fixation activity was stimulated with elevated CO 2 and inhibited by elevated O 3 Elevated CO 2 ameliorated detrimental O 3 effects to varying extents depending on the concentrations of the two gases. These results indicated that interactions between CO 2 and O 3 on plant physiology can alter N acquisition processes, with impacts on peanut productivity likely dependent in part on these changes. DA - 2009/// PY - 2009/// DO - 10.2135/cropsci2008.10.0603 VL - 49 IS - 5 SP - 1827-1836 SN - 1435-0653 ER - TY - JOUR TI - Coupled biogeochemical cycling of iron and manganese as mediated by microbial siderophores AU - Duckworth, Owen W. AU - Bargar, John R. AU - Sposito, Garrison T2 - BIOMETALS DA - 2009/8// PY - 2009/8// DO - 10.1007/s10534-009-9220-9 VL - 22 IS - 4 SP - 605-613 SN - 1572-8773 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-67651242008&partnerID=MN8TOARS KW - Dissolution KW - Ligand exchange KW - Sorption KW - Siderophore KW - Iron KW - Manganese ER - TY - JOUR TI - Characterization of enterococci populations in livestock manure using BIOLOG AU - Graves, Alexandria AU - Weaver, R. W. AU - Entry, James T2 - MICROBIOLOGICAL RESEARCH AB - The BIOLOG system was used to generate knowledge of enterococci populations found in fresh and dry manure of livestock (cattle (Bos taurus), horse (Equus caballus), and sheep (Ovis aires)). Six-hundred and forty Enterococcus isolates from the host sources were observed as a combined fresh manure unit and a combined dry manure unit, E. casseliflavus and E. mundtii were predominant in fresh manure (36% and 35%, respectively) as well as in dry manure (51% and 28%, respectively). The other species were found at a frequency of less than 10%. A chi-square test of the two most predominant Enterococcus sp. indicated that there were some significant differences among the frequency of E. casseliflavus and E. mundtii in cattle and sheep, but not horse. Despite these differences, these two species were overwhelmingly predominant among all three livestock sources. DA - 2009/// PY - 2009/// DO - 10.1016/j.micres.2006.11.017 VL - 164 IS - 3 SP - 260-266 SN - 0944-5013 KW - BIOLOG KW - Enterococcus KW - Livestock KW - Manure ER - TY - JOUR TI - Biogeochemistry of iron oxidation in a circumneutral freshwater habitat AU - Duckworth, Owen W. AU - Holmstroem, Sara J. M. AU - Pena, Jasquelin AU - Sposito, Garrison T2 - CHEMICAL GEOLOGY AB - Iron(II) oxidation in natural waters at circumneutral pH, often regarded as an abiotic process, is frequently biologically mediated at iron-rich redox gradients. West Berry Creek, a small circumneutral tributary that flows through a mixed coniferous forest in Big Basin State Park, California, contains localized iron (hydr)oxide precipitates at points along its course where anoxic groundwater meets oxygenated creek water. These mixing zones establish redox gradients that may be exploited by microbes forming microbial mats that are intimately associated with iron (hydr)oxide precipitates. Water sampling revealed strong correlations between the concentrations of aqueous inorganic species, suggesting a rock-weathering source for most of these solutes. Liquid chromatography–electrospray ionization–mass spectrometry techniques detected significant concentrations of organic exudates, including low molecular mass organic acids and siderophores, indicating that active biogeochemical cycling of iron is occurring in the creek. X-ray diffraction and elemental analysis showed the precipitates to be amorphous, or possibly poorly crystalline, iron-rich minerals. Clone libraries developed from 16S rDNA sequences extracted from microbial mat communities associated with the precipitates revealed the presence of microorganisms related to the neutrophilic iron oxidizing bacteria Gallionella and Sideroxydans. Sequences from these libraries also indicated the presence of significant populations of organisms related to bacteria in the genera Aquaspirillum, Pseudomonas, Sphingomonas, and Nitrospira. These geosymbiotic systems appear to be significant not only for the biogeochemical cycling of iron in the creek, but also for the cycling of organic species, inorganic nutrients, and trace metals. DA - 2009/3/30/ PY - 2009/3/30/ DO - 10.1016/j.chemgeo.2008.08.027 VL - 260 IS - 3-4 SP - 149-158 SN - 0009-2541 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-60749134694&partnerID=MN8TOARS KW - Iron oxide KW - Biomineral KW - Siderophores KW - Organic acids KW - Neutrophilic iron oxidizing bacteria KW - Circumneutral iron oxidation ER - TY - JOUR TI - The exceptionally stable cobalt(III)-desferrioxamine B complex AU - Duckworth, Owen W. AU - Bargar, John R. AU - Jarzecki, Andrzej A. AU - Oyerinde, Oyeyemi AU - Spiro, Thomas G. AU - Sposito, Garrison T2 - MARINE CHEMISTRY AB - The biogeochemistry of trivalent iron, manganese, and cobalt in the oceans is dominated by soluble complexes formed with high-affinity organic ligands that are believed to be microbial siderophores or similar biogenic chelating agents. Desferrioxamine B (DFOB), a trihydroxamate siderophore found in both terrestrial and marine environments, has served as a useful model for a large class of microbial siderophores in studies of 1:1 complexes formed with trivalent iron and manganese. However, no data exist concerning DFOB complexes with Co(III), which we hypothesize should be as strong as those with Fe(III) and Mn(III) if the current picture of the ocean biogeochemistry of the three trivalent metals is accurate. We investigated the complexation reaction between DFOB and Co(III) in aqueous solution at seawater pH using base and redox titrations, and then characterized the resulting 1:1 complex Co(III)HDFOB+ using X-ray absorption, resonance Raman spectroscopy, and quantum mechanical structural optimizations. We found that the complex stability constant for Co(III)HDFOB+ (log K [Co(III)HDFOB+] = 37.5 ± 0.4) is in fact five and seven orders of magnitude larger than that for Fe(III)HDFOB+ (log K[Fe(III)HDFOB+] = 32.02) and Mn(III)HDFOB+ (log K[Mn(III)HDFOB+] = 29.9), respectively. Spectroscopic data and the supporting theoretical structural optimizations elucidated the molecular basis for this exceptional stability. Although not definitive, our results nevertheless are consistent with the evolution of siderophores as a response by bacteria to oxygenation, not only because of sharply decreasing concentrations of Fe(III), but also of Co(III). DA - 2009/1/30/ PY - 2009/1/30/ DO - 10.1016/j.marchem.2009.01.003 VL - 113 IS - 1-2 SP - 114-122 SN - 1872-7581 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-60949105860&partnerID=MN8TOARS KW - Biogeochemistry KW - Cobalt KW - Iron KW - Chelates KW - Siderophores KW - Speciation ER - TY - JOUR TI - The Ozone Component of Global Change: Potential Effects on Agricultural and Horticultural Plant Yield, Product Quality and Interactions with Invasive Species AU - Booker, Fitzgerald AU - Muntifering, Russell AU - McGrath, Margaret AU - Burkey, Kent AU - Decoteau, Dennis AU - Fiscus, Edwin AU - Manning, William AU - Krupa, Sagar AU - Chappelka, Arthur AU - Grantz, David T2 - JOURNAL OF INTEGRATIVE PLANT BIOLOGY AB - The productivity, product quality and competitive ability of important agricultural and horticultural plants in many regions of the world may be adversely affected by current and anticipated concentrations of ground-level ozone (O3). Exposure to elevated O3 typically results in suppressed photosynthesis, accelerated senescence, decreased growth and lower yields. Various approaches used to evaluate O3 effects generally concur that current yield losses range from 5% to 15% among sensitive plants. There is, however, considerable genetic variability in plant responses to O3. To illustrate this, we show that ambient O3 concentrations in the eastern United States cause substantially different levels of damage to otherwise similar snap bean cultivars. Largely undesirable effects of O3 can also occur in seed and fruit chemistry as well as in forage nutritive value, with consequences for animal production. Ozone may alter herbicide efficacy and foster establishment of some invasive species. We conclude that current and projected levels of O3 in many regions worldwide are toxic to sensitive plants of agricultural and horticultural significance. Plant breeding that incorporates O3 sensitivity into selection strategies will be increasingly necessary to achieve sustainable production with changing atmospheric composition, while reductions in O3 precursor emissions will likely benefit world food production and reduce atmospheric concentrations of an important greenhouse gas. DA - 2009/4// PY - 2009/4// DO - 10.1111/j.1744-7909.2008.00805.x VL - 51 IS - 4 SP - 337-351 SN - 1744-7909 KW - climate change KW - crop KW - forage KW - horticultural plant KW - ozone KW - product quality KW - weed KW - yield ER - TY - JOUR TI - Foliar resistance to ozone injury in the genetic base of US and Canadian soybean and prediction of resistance in descendent cultivars using coefficient of parentage AU - Burkey, Kent O. AU - Carter, Thomas E., Jr. T2 - FIELD CROPS RESEARCH AB - Development of ozone (O3)-resistant cultivars is a potentially important approach for maintaining crop productivity under future climate scenarios in which tropospheric O3 pollution is projected to rise. A first step in the breeding of resistant cultivars for a crop such as soybean (Glycine max (L.) Merr.) is identification of sources of O3 resistance genes. Thirty ancestral lines of soybean were screened for differences in O3 foliar injury under greenhouse conditions. The ancestors represented 92% of the genetic base of North American soybean as determined by pedigree analysis. Injury among ancestors ranged from 5 to 50% of leaf area, based on response of the five oldest main stem leaves, indicating both the presence of substantial genetic variation for O3 injury among the ancestors as well as resistance levels greater than that of the standard control cultivar, resistant Essex (15% injury). Ancestral types Fiskeby 840-7-3 and Fiskeby III exhibited the greatest foliar resistance and PI 88788 the least. A subsequent field study confirmed the foliar resistance of the Fiskeby types. Resistant ancestors identified here are proposed for inheritance and DNA mapping studies to determine the genetic basis of foliar resistance. Because the presence of O3-resistant ancestors suggested that resistant descendents may exist in addition to the resistant control Essex, a method was developed to facilitate their identification. A predicted O3-resistance score was calculated for 247 publicly-released cultivars, based on pedigree analysis and ancestral response to ozone. Using this approach, the 32 public cultivars most closely related to resistant ancestors and, thus, most likely to be resistant were identified as priority candidates for future screening efforts. Predicted scores from the analysis suggested that cultivars from the Midwest may be more sensitive to foliar injury, on average, than Southern cultivars. DA - 2009/4/11/ PY - 2009/4/11/ DO - 10.1016/j.fcr.2008.12.005 VL - 111 IS - 3 SP - 207-217 SN - 0378-4290 KW - Ancestor KW - Coefficient of parentage KW - Foliar injury KW - Ozone tolerance KW - Soybean ER - TY - JOUR TI - Effect of a Chromosome Segment Marked by the Ph-p Gene for Resistance to Phytophthora nicotianae on Reproduction of Tobacco Cyst Nematodes AU - Johnson, C. S. AU - Wernsman, E. A. AU - LaMondia, J. A. T2 - PLANT DISEASE AB - Host resistance is an important strategy for managing Globodera tabacum subsp. solanacearum and G. tabacum subsp. tabacum, important nematode pests of flue-cured tobacco (Nicotiana tabacum) in Virginia, and cigar wrapper tobacco (N. tabacum) in Connecticut and Massachusetts, respectively. Field research from 1992 to 2005 evaluated reproduction of G. tabacum subsp. solanacearum on genotypes with and without a chromosome segment from N. plumbaginifolia containing a gene (Ph p ) that conferred resistance to race 0 of Phytophthora nicotianae (causal agent of tobacco black shank). Ratios of G. tabacum subsp. solanacearum eggs/500 cm 3 soil at the end versus the beginning of experiments (P f /P i ) were significantly lower in cultivars and breeding lines possessing the Ph p -containing chromosome segment from N. plumbaginifolia compared with genotypes without the segment. Numbers of vermiform G. tabacum subsp. solanacearum juveniles in roots were similar among genotypes but numbers of swollen and pyriform nematodes were significantly lower for the known G. tabacum subsp. solanacearum resistant cv. NC 567 and in genotypes possessing the Ph p gene compared with genotypes and cultivars without the gene. In a 2003 greenhouse test, the percentage of plants with visible G. tabacum subsp. tabacum cysts was also significantly lower for parental and progeny genotypes homozygous and heterozygous, respectively, for Ph p compared with similar lines without the gene. These results indicate a close linkage or association between a likely single, dominant gene (Ph p ) for resistance to P. nicotianae and suppressed reproduction by G. tabacum subsp. solanacearum and G. tabacum subsp. tabacum. Further research to accurately elucidate the relationships among these genes could lead to significant improvements in tobacco disease control. DA - 2009/3// PY - 2009/3// DO - 10.1094/PDIS-93-3-0309 VL - 93 IS - 3 SP - 309-315 SN - 1943-7692 ER - TY - JOUR TI - Mapping and Comparison of Quantitative Trait Loci for Oleic Acid Seed Content in Two Segregating Soybean Populations AU - Bachlava, Eleni AU - Dewey, Ralph E. AU - Burton, Joseph W. AU - Cardinal, Andrea J. T2 - CROP SCIENCE AB - Soybean [ Glycine max (L.) Merr.] produces 29.4% of the world's edible vegetable oil. An important determinant of the nutritional value and the oxidative stability of soybean oil is the oleic acid content. Elevation of the oleate content levels leads to the improvement of soybean oil quality. However, our knowledge of the genetic factors underlying oleate variation in soybean seeds remains incomplete, hampering the use of marker‐assisted selection in soybean breeding programs. We used a whole‐genome scan approach to identify oleate quantitative trait loci (QTLs) in a soybean population segregating for oleic acid content and a cognate segregating population to confirm oleate QTL. A novel oleate QTL with moderate effects was revealed on linkage group F in the proximity of the simple sequence repeat marker sat_309, which was confirmed in both populations across all environments tested. Furthermore, this study verified the existence of an oleate QTL with moderate effects in the proximity of FAD2‐1B isoform on linkage group I, which interacted epistatically with the oleate QTL on linkage group F. Oleate QTLs with moderate effects were also detected on linkage groups A2 and N only in one of the populations under study. Minor QTLs on linkage groups E, L, A1, and D2 confirmed previous mapping studies for oleate content in soybean. DA - 2009/// PY - 2009/// DO - 10.2135/cropsci2008.06.0324 VL - 49 IS - 2 SP - 433-442 SN - 1435-0653 ER - TY - JOUR TI - Downward Mobility of C-14-Labeled Simazine in a Bermudagrass System vs. a Fallow Soil System AU - Cummings, H. D. AU - Weber, J. B. AU - Yelverton, F. H. AU - Leidy, R. B. T2 - CROP SCIENCE AB - Pesticides applied to bermudagrass ( Cynodon dactylon L.) can be captured by the canopy, absorbed by the roots, or bound in the thatch layer, which reduces the amount available to leach compared with a fallow soil system where pesticides may be applied directly to soil. 14 C‐Simazine was applied to dormant bermudagrass and fallow soil in lysimeters in a cold growth chamber (5°C) (cold‐fallow soil) and to actively growing bermudagrass and fallow soil in lysimeters in a greenhouse (25°C) (warm‐fallow soil) in April. Following clipping collection, lysimeters were irrigated with 5 cm of water every 3–4 d, and leachate was collected. After 25 d, lysimeters were divided into 2‐cm increments from 0 to 10 cm, then 5‐cm increments from 10 to 30 cm. Because of evapotranspiration, actively growing bermudagrass and warm‐fallow soil yielded significantly less leachate than dormant bermudagrass and cold‐fallow soil indicating less moisture is available for downward movement during summer. After the addition of 31 cm of irrigation, the greatest quantities of 14 C‐simazine were in the 0‐ to 2‐cm increment for all treatments and decreased with depth. Although the greatest quantities of 14 C‐simazine in leachate occurred in dormant bermudagrass, the reached factor was greatest for cold‐fallow soil (0.20), followed by dormant bermudagrass (0.17), warm‐fallow soil (0.16), and actively growing bermudagrass (0.14). Therefore, simazine is least mobile in bermudagrass during summer and most mobile in fallow soil in winter. DA - 2009/// PY - 2009/// DO - 10.2135/cropsci2008.05.0297 VL - 49 IS - 2 SP - 704-713 SN - 1435-0653 ER - TY - JOUR TI - Changes in Genetic Diversity of US Flue-Cured Tobacco Germplasm over Seven Decades of Cultivar Development AU - Moon, H. S. AU - Nicholson, J. S. AU - Heineman, A. AU - Lion, K. AU - Hoeven, P. AU - Hayes, A. J. AU - Lewis, R. S. T2 - CROP SCIENCE AB - Plant breeding methodologies have been applied to flue‐cured tobacco ( Nicotiana tabacum L.) for approximately seven decades. As has been observed in several other crops, stringent quality requirements have resulted in use of conservative breeding strategies in the development of new cultivars. The impact of breeding practices on genetic diversity within U.S. flue‐cured tobacco germplasm has not been investigated. In this study, we genotyped 117 tobacco cultivars from eight sequential time periods with 71 microsatellite primer pairs. A total of 294 alleles were scored. Only a fraction (48%) of alleles present in the initial germplasm pool was represented in cultivars released during the 1990s and 2000s. Only 13 and 18 alleles were detected in the 1990s and 2000s, respectively, which were undetected in the initial gene pool. The overall trend was one of gradual reduction in allelic counts at microsatellite loci, indicating a reduction in diversity over time at the gene level. Average genetic similarity was highest among cultivars of the 1990s and 2000s, reflecting a reduction in genetic diversity at the population level. This observed narrowing of the U.S. flue‐cured tobacco germplasm base in combination with low rates of genetic gain for yield in the last 20 years may point to a need for diversification of parental materials used in future breeding crosses. Reported genetic relationships among the group of genotyped cultivars may be valuable for future strategic germplasm choices. DA - 2009/// PY - 2009/// DO - 10.2135/cropsci2008.05.0253 VL - 49 IS - 2 SP - 498-508 SN - 1435-0653 ER - TY - JOUR TI - Weed Management in Peanut with Herbicide Combinations Containing Imazapic and Other Pesticides AU - Jordan, David L. AU - Lancaster, Sarah H. AU - Lanier, James E. AU - Lassiter, Bridget R. AU - Johnson, P. Dewayne T2 - WEED TECHNOLOGY AB - Research was conducted in North Carolina to compare weed control by various rates of imazapic POST alone or following diclosulam PRE. In a second experiment, weed control by imazapic applied POST alone or with acifluoren, diclosulam, or 2,4-DB was compared. In a final experiment, yellow nutsedge control by imazapic alone and with the fungicides azoxystrobin, chlorothalonil, pyraclostrobin, and tebuconazole was compared. Large crabgrass was controlled more effectively by imazapic POST than diclosulam PRE. Common lambsquarters, common ragweed, and eclipta were controlled more effectively by diclosulam PRE than imazapic POST. Nodding spurge was controlled similarly by both herbicides. Few differences in control were noted when comparing imazapic rates after diclosulam PRE. Applying either diclosulam PRE or imazapic POST alone or in combination increased peanut yield over nontreated peanut in five of six experiments. Few differences in pod yield were noted when comparing imazapic rates. Acifluorfen, diclosulam, and 2,4-DB did not affect entireleaf morningglory, large crabgrass, nodding spurge, pitted morningglory, and yellow nutsedge control by imazapic. Eclipta control by coapplication of imazapic and diclosulam exceeded control by imazapic alone. The fungicides azoxystrobin, chlorothalonil, pyraclostrobin, and tebuconazole did not affect yellow nutsedge control by imazapic. DA - 2009/// PY - 2009/// DO - 10.1614/WT-08-041.1 VL - 23 IS - 1 SP - 6-10 SN - 1550-2740 KW - Pesticide compatibility KW - weed management ER - TY - JOUR TI - Virginia Creeper (Parthenocissus quinquefolia) and Wild Grape (Vitis spp.) Control in Fraser Fir AU - Richardson, Robert J. AU - Marshall, Michael W. AU - Uhlig, Robert E. AU - Zandstra, Bernard H. T2 - WEED TECHNOLOGY AB - Virginia creeper and wild grape are troublesome perennial vines that often infest Christmas tree plantations. Field studies were conducted to evaluate Fraser fir injury and Virginia creeper and wild grape control with directed applications of triclopyr (1,680 g ai/ha) alone and in combination with 2,4-D (1,120 g ai/ha), clopyralid (280 g ai/ha), and halosulfuron (36 g ai/ha). Additional treatments included 2,4-D, clopyralid, glyphosate (1,120 g ai/ha), halosulfuron, hexazinone (560 g ai/ha), mesotrione (105 g ai/ha), and sulfometuron (71 g ai/ha) applied alone; and a mixture of hexazinone plus mesotrione. In the triclopyr-containing treatments, Fraser fir injury ranged from 6 to 13% at 1 mo after treatment (MAT) and was 4 to 8% at 11 MAT. Leader growth was not impacted by the herbicide treatments. At 11 MAT, all triclopyr-containing treatments controlled Virginia creeper 93 to 98% and wild grape 98 to 100%, which was greater than the control observed with glyphosate at 63 and 59%, respectively. Virginia creeper and wild grape control with 2,4-D was 88 to 90%. Clopyralid, halosulfuron, hexazinone, hexazinone plus mesotrione, mesotrione, and sulfometuron provided less than 66% control of both perennial vines. Directed applications of triclopyr-containing treatments or 2,4-D were effective management tools for selective removal of wild grape and Virginia creeper from Fraser fir Christmas tree plantations. Additional research is needed on the potential sensitivity of other commonly grown Christmas tree species to triclopyr-containing treatments. DA - 2009/// PY - 2009/// DO - 10.1614/WT-08-028.1 VL - 23 IS - 1 SP - 184-187 SN - 0890-037X KW - Perennial vines KW - silviculture KW - Christmas trees KW - conifer KW - competition KW - plantation ER - TY - JOUR TI - Using a Grower Survey to Assess the Benefits and Challenges of Glyphosate-Resistant Cropping Systems for Weed Management in US Corn, Cotton, and Soybean AU - Shaw, David R. AU - Givens, Wade A. AU - Farno, Luke A. AU - Gerard, Patrick D. AU - Jordan, David AU - Johnson, William G. AU - Weller, Stephen C. AU - Young, Bryan G. AU - Wilson, Robert G. AU - Owen, Michael D. K. T2 - WEED TECHNOLOGY AB - Over 175 growers in each of six states (Illinois, Indiana, Iowa, Mississippi, Nebraska, and North Carolina) were surveyed by telephone to assess their perceptions of the benefits of utilizing the glyphosate-resistant (GR) crop trait in corn, cotton, and soybean. The survey was also used to determine the weed management challenges growers were facing after using this trait for a minimum of 4 yr. This survey allowed the development of baseline information on how weed management and crop production practices have changed since the introduction of the trait. It provided useful information on common weed management issues that should be addressed through applied research and extension efforts. The survey also allowed an assessment of the perceived levels of concern among growers about glyphosate resistance in weeds and whether they believed they had experienced glyphosate resistance on their farms. Across the six states surveyed, producers reported 38, 97, and 96% of their corn, cotton, and soybean hectarage planted in a GR cultivar. The most widely adopted GR cropping system was a GR soybean/non-GR crop rotation system; second most common was a GR soybean/GR corn crop rotation system. The non-GR crop component varied widely, with the most common crops being non-GR corn or rice. A large range in farm size for the respondents was observed, with North Carolina having the smallest farms in all three crops. A large majority of corn and soybean growers reported using some type of crop rotation system, whereas very few cotton growers rotated out of cotton. Overall, rotations were much more common in Midwestern states than in Southern states. This is important information as weed scientists assist growers in developing and using best management practices to minimize the development of glyphosate resistance. DA - 2009/// PY - 2009/// DO - 10.1614/WT-08-042.1 VL - 23 IS - 1 SP - 134-149 SN - 1550-2740 KW - Crop diversity KW - crop rotation KW - glyphosate-resistant crops KW - resistance management KW - survey ER - TY - JOUR TI - US Grower Views on Problematic Weeds and Changes in Weed Pressure in Glyphosate-Resistant Corn, Cotton, and Soybean Cropping Systems AU - Kruger, Greg R. AU - Johnson, William G. AU - Weller, Stephen C. AU - Owen, Micheal D. K. AU - Shaw, David R. AU - Wilcut, John W. AU - Jordan, David L. AU - Wilson, Robert G. AU - Bernards, Mark L. AU - Young, Bryan G. T2 - WEED TECHNOLOGY AB - Corn and soybean growers in Illinois, Indiana, Iowa, Mississippi, Nebraska, and North Carolina, as well as cotton growers in Mississippi and North Carolina, were surveyed about their views on changes in problematic weeds and weed pressure in cropping systems based on a glyphosate-resistant (GR) crop. No growers using a GR cropping system for more than 5 yr reported heavy weed pressure. Over all cropping systems investigated (continuous GR soybean, continuous GR cotton, GR corn/GR soybean, GR soybean/non-GR crop, and GR corn/non-GR crop), 0 to 7% of survey respondents reported greater weed pressure after implementing rotations using GR crops, whereas 31 to 57% felt weed pressure was similar and 36 to 70% indicated that weed pressure was less. Pigweed, morningglory, johnsongrass, ragweed, foxtail, and velvetleaf were mentioned as their most problematic weeds, depending on the state and cropping system. Systems using GR crops improved weed management compared with the technologies used before the adoption of GR crops. However, the long-term success of managing problematic weeds in GR cropping systems will require the development of multifaceted integrated weed management programs that include glyphosate as well as other weed management tactics. DA - 2009/// PY - 2009/// DO - 10.1614/WT-08-040.1 VL - 23 IS - 1 SP - 162-166 SN - 1550-2740 KW - Crop rotation KW - glyphosate-resistant crops KW - glyphosate-resistant weeds KW - survey KW - weed shifts ER - TY - JOUR TI - The influence of chemistry, production and community composition on leaf litter decomposition under elevated atmospheric CO2 and tropospheric O-3 in a northern hardwood ecosystem AU - Liu, L. L. AU - King, J. S. AU - Giardina, C. P. AU - Booker, F. L. T2 - Ecosystems DA - 2009/// PY - 2009/// DO - 10.1007/s10021-009-9231-y VL - 12 IS - 3 SP - 401-416 ER - TY - JOUR TI - Survey of Tillage Trends Following the Adoption of Glyphosate-Resistant Crops AU - Givens, Wade A. AU - Shaw, David R. AU - Kruger, Greg R. AU - Johnson, William G. AU - Weller, Stephen C. AU - Young, Bryan G. AU - Wilson, Robert G. AU - Owen, Micheal D. K. AU - Jordan, David T2 - WEED TECHNOLOGY AB - A phone survey was administered to 1,195 growers in six states (Illinois, Indiana, Iowa, Mississippi, Nebraska, and North Carolina). The survey measured producers' crop history, perception of glyphosate-resistant (GR) weeds, past and present weed pressure, tillage practices, and herbicide use as affected by the adoption of GR crops. This article describes the changes in tillage practice reported in the survey. The adoption of a GR cropping system resulted in a large increase in the percentage of growers using no-till and reduced-till systems. Tillage intensity declined more in continuous GR cotton and GR soybean (45 and 23%, respectively) than in rotations that included GR corn or non-GR crops. Tillage intensity declined more in the states of Mississippi and North Carolina than in the other states, with 33% of the growers in these states shifting to more conservative tillage practices after the adoption of a GR crop. This was primarily due to the lower amount of conservation tillage adoption in these states before GR crop availability. Adoption rates of no-till and reduced-till systems increased as farm size decreased. Overall, producers in a crop rotation that included a GR crop shifted from a relatively more tillage-intense system to reduced-till or no-till systems after implementing a GR crop into their production system. DA - 2009/// PY - 2009/// DO - 10.1614/WT-08-038.1 VL - 23 IS - 1 SP - 150-155 SN - 1550-2740 KW - Tillage system KW - glyphosate KW - farmer survey ER - TY - JOUR TI - Shoot regeneration of dwarf dogwood (Cornus canadensis L.) and morphological characterization of the regenerated plants AU - Feng, Chun-Miao AU - Qu, Rongda AU - Zhou, Li-Li AU - Xie, De-Yu AU - Xiang, Qiu-Yun T2 - PLANT CELL TISSUE AND ORGAN CULTURE DA - 2009/4// PY - 2009/4// DO - 10.1007/s11240-009-9495-0 VL - 97 IS - 1 SP - 27-37 SN - 1573-5044 KW - Cornus canadensis KW - Organogenesis KW - Regeneration KW - Rhizomes KW - Tissue culture ER - TY - JOUR TI - Improving construction site runoff quality with fiber check dams and polyacrylamide AU - McLaughlin, R. A. AU - King, S. E. AU - Jennings, G. D. T2 - JOURNAL OF SOIL AND WATER CONSERVATION AB - Sediment and turbidity are among the most common pollutants affecting surface waters, resulting in reduced reservoir capacity, degradation of aquatic organism habitat, and decreased aesthetic value. Construction activities, including roadway projects, can be significant contributors to sediment loading in streams and lakes. We studied water quality in stormwater runoff from three systems for erosion and sediment control on two roadway projects in the North Carolina mountains. The first roadway project was divided into three experimental sections, each with one the following treatments installed in the adjacent drainage ditch: (1) the standard best management practice (BMP) consisting of narrow sediment traps in the ditch along with rock check dams, (2) fiber check dams (FCDs) consisting of a mix of straw wattles and coir logs, or (3) FCDs with granulated, anionic polyacrylamide (PAM) added to each. The second project was smaller and included only two of the experimental sections described above: (1) the standard BMPs and (2) FCDs with PAM. Significant reductions in turbidity and total suspended solids were obtained using the FCDs, particularly those with PAM added. At site 1, from June 2006 to March 2007, the average turbidity values for the stormwater runoff were 3,813 nephelometric turbidity units (NTU) for the standard BMPs, 202 NTU for the FCDs-only, and 34 NTU for the FCDs with PAM. Average turbidity in discharges at site 2 was reduced from 867 NTU for the standard BMPs to 115 NTU for the FCDs with PAM. Sediment loading at both sites was similarly reduced with the use of FCDs. At site 1, the standard BMPs lost an average of 428 kg (944 lb) of sediment per storm event compared to just 2.1 kg (4.6 lb) for the FCDs-only and 0.9 kg (2.0 lb) for the FCDs with PAM. At site 2, the standard BMPs lost an average of 3.3 kg (7.3 lb) per storm event compared with 0.8 kg (1.8 lb) for the FCDs with PAM. A conservative economic analysis suggests that the costs of the FCDs are lower than the standard BMPs. This study suggests that the use of FCDs with PAM can bring discharges from similar linear construction projects much closer to the regulatory guidelines for non-point source discharges than the current standard practices. DA - 2009/// PY - 2009/// DO - 10.2489/jswc.64.2.144 VL - 64 IS - 2 SP - 144-154 SN - 1941-3300 KW - check dams KW - erosion control KW - polyacrylamide (PAM) KW - sediment loading KW - turbidity reduction KW - wattles ER - TY - JOUR TI - Hydroxamate siderophore-promoted reactions between iron(II) and nitroaromatic groundwater contaminants AU - Kim, Dongwook AU - Duckworth, Owen W. AU - Strathmann, Timothy J. T2 - GEOCHIMICA ET COSMOCHIMICA ACTA AB - Recent studies show that ferrous iron (FeII), which is often abundant in anaerobic soil and groundwater, is capable of abiotically reducing many subsurface contaminants. However, studies also demonstrate that FeII redox reactivity in geochemical systems is heavily dependent upon metal speciation. This contribution examines the influence of hydroxamate ligands, including the trihydroxamate siderophore desferrioxamine B (DFOB), on FeII reactions with nitroaromatic groundwater contaminants (NACs). Experimental results demonstrate that ring-substituted NACs are reduced to the corresponding aniline products in aqueous solutions containing FeII complexes with DFOB and two monohydroxamate ligands (acetohydroxamic acid and salicylhydroxamic acid). Reaction rates are heavily dependent upon solution conditions and the identities of both the FeII–complexing hydroxamate ligand and the target NAC. Trends in the observed pseudo-first-order rate constants for reduction of 4-chloronitrobenzene (kobs, s−1) are quantitatively linked to the formation of FeII species with standard one-electron reduction potentials, EH0 (FeIII/FeII), below −0.3 V. Linear free energy relationships correlate reaction rates with the EH0 (FeIII/FeII) values of different electron-donating FeII complexes and with the apparent one-electron reduction potentials of different electron-accepting NACs, EH1′(ArNO2). Experiments describing a redox auto-decomposition mechanism for FeII–DFOB complexes that occurs at neutral pH and has implications for the stability of hydroxamate siderophores in anaerobic environments are also presented. Results from this study indicate that hydroxamates and other FeIII-stabilizing organic ligands can form highly redox-active FeII complexes that may contribute to the natural attenuation and remediation of subsurface contaminants. DA - 2009/3/1/ PY - 2009/3/1/ DO - 10.1016/j.gca.2008.11.039 VL - 73 IS - 5 SP - 1297-1311 SN - 1872-9533 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-59649115651&partnerID=MN8TOARS ER - TY - JOUR TI - Heterogeneous distribution of weedy Paspalum species and edaphic variables in turfgrass AU - Henry, G. M. AU - Burton, M. G. AU - Yelverton, F. H. T2 - HortScience DA - 2009/// PY - 2009/// VL - 44 IS - 2 SP - 447-451 ER - TY - CHAP TI - Genomics of cotton fiber secondary wall deposition and cellulose biogenesis AU - Haigler, Candace H. AU - Singh, B. AU - Wang, G.-R. AU - Zhang, D. T2 - Genetics and genomics of cotton AB - The deposition of > 90% cellulose in the cotton fiber secondary wall makes this unique cell powerful for understanding cellulose biogenesis, a process with great importance in nature and industry. This chapter provides an overview of cellulose biogenesis, summarizes how cotton fiber has previously facilitated unique insights in this field, and explains how cellulose is important in terms of cotton fiber physical properties. The nature of the cotton fiber secondary wall transcriptome is discussed, including comparisons to primary-wall-stage fiber and the Arabidopsis proteome. Microarray data, including validation by quantitative reverse transcription PCR, are described to show that transcriptomes for secondary wall deposition in cotton fiber and xylem are similar. The functional context of selected genes that are up-regulated for secondary wall deposition is discussed. PY - 2009/// DO - 10.1007/978-0-387-70810-2_16 SP - 385–417 PB - New York: Springer Science & Business Media SN - 9780387708096 ER - TY - JOUR TI - A Grower Survey of Herbicide Use Patterns in Glyphosate-Resistant Cropping Systems AU - Givens, Wade A. AU - Shaw, David R. AU - Johnson, William G. AU - Weller, Stephen C. AU - Young, Bryan G. AU - Wilson, Robert G. AU - Owen, Micheal D. K. AU - Jordan, David T2 - WEED TECHNOLOGY AB - A telephone survey was conducted with growers in Iowa, Illinois, Indiana, Nebraska, Mississippi, and North Carolina to discern the utilization of the glyphosate-resistant (GR) trait in crop rotations, weed pressure, tillage practices, herbicide use, and perception of GR weeds. This paper focuses on survey results regarding herbicide decisions made during the 2005 cropping season. Less than 20% of the respondents made fall herbicide applications. The most frequently used herbicides for fall applications were 2,4-D and glyphosate, and these herbicides were also the most frequently used for preplant burndown weed control in the spring. Atrazine and acetochlor were frequently used in rotations containing GR corn. As expected, crop rotations using a GR crop had a high percentage of respondents that made one to three POST applications of glyphosate per year. GR corn, GR cotton, and non-GR crops had the highest percentage of growers applying non-glyphosate herbicides during the 2005 growing season. A crop rotation containing GR soybean had the greatest negative impact on non-glyphosate use. Overall, glyphosate use has continued to increase, with concomitant decreases in utilization of other herbicides. DA - 2009/// PY - 2009/// DO - 10.1614/WT-08-039.1 VL - 23 IS - 1 SP - 156-161 SN - 1550-2740 KW - Postemergence KW - preemergence KW - preplant burndown KW - soil residual herbicides KW - tank mixtures KW - weed management ER - TY - JOUR TI - Use of selection with recurrent backcrossing and QTL mapping to identify loci contributing to southern leaf blight resistance in a highly resistant maize line AU - Zwonitzer, John C. AU - Bubeck, David M. AU - Bhattramakki, Dinakar AU - Goodman, Major M. AU - Arellano, Consuelo AU - Balint-Kurti, Peter J. T2 - THEORETICAL AND APPLIED GENETICS DA - 2009/3// PY - 2009/3// DO - 10.1007/s00122-008-0949-2 VL - 118 IS - 5 SP - 911-925 SN - 1432-2242 ER - TY - JOUR TI - Radiation Interception and Yield Response to Increased Leaflet Number in Early-Maturing Soybean Genotypes AU - Seversike, Thomas M. AU - Purcell, Larry C. AU - Gbur, Edward AU - Chen, Pengyin AU - Scott, Roy T2 - CROP SCIENCE AB - ABSTRACT Early‐maturing soybean [ Glycine max (L.) Merr.] cultivars require less irrigation than full‐season cultivars and may mature before drought periods most often occur in the midsouthern United States. These cultivars require high plant‐population densities for radiation interception and acceptable yields, which increase costs. We hypothesized that seven‐leaflet genotypes would have greater leaf area per plant, resulting in more radiation interception and higher yield than near‐isogenic three‐leaflet genotypes at similar populations. Near‐isogenic lines from maturity groups 00 to 1.8 were seeded at rates from 4 to 80 m −2 The fraction of photosynthetically active radiation (PAR) intercepted by plots was measured using digital imagery and used to estimate cumulative intercepted PAR (CIPAR). Although seven‐leaflet isolines had greater leaf area per leaf than three‐leaflet isolines, leaf area per plant was similar between three‐ and seven‐leaflet isolines because the three‐leaflet isolines had a slightly greater number of main‐stem leaves than seven‐leaflet isolines. Generally, seven‐leaflet isolines had 10 to 21% greater CIPAR at populations ≤40 m −2 compared to three‐leaflet isolines. At populations ≤20 m −2 , seven‐leaflet isolines generally had higher yields than three‐leaflet isolines, but yields at these low populations were inherently low and agronomically unacceptable. DA - 2009/// PY - 2009/// DO - 10.2135/cropsci2007.08.0472 VL - 49 IS - 1 SP - 281-289 SN - 1435-0653 ER - TY - JOUR TI - Performance of growing cattle grazing stockpiled Jesup tall fescue with varying endophyte status AU - Drewnoski, M. E. AU - Oliphant, E. J. AU - Marshall, B. T. AU - Poore, M. H. AU - Green, J. T. AU - Hockett, M. E. T2 - JOURNAL OF ANIMAL SCIENCE AB - The objective of this study was to evaluate the performance of growing cattle when intensively grazing stockpiled endophyte-infected (E+), endophyte-free (E-), and nontoxic endophyte-infected (EN) tall fescue during the winter. The experiment was conducted over 5 consecutive winters. In each year, plots (1 ha each, 4 per treatment) were harvested for hay in August, fertilized in September, and forage was allowed to accumulate until grazing was initiated in early December. Each year, 48 Angus-cross tester cattle (4 per plot) were given a daily allotment of forage, under strip-grazing (frontal grazing) management, with a target residual height of 5 cm. Steers were used the first year, and heifers were used in subsequent years. The grazing periods for determination of pasture ADG were 86 d (yr 1), 70 d (yr 2), 86 d (yr 3), 72 d (yr 4), and 56 d (yr 5). Pasture ADG of cattle did not differ among treatments (P = 0.13) and were 0.51, 0.59, and 0.56 kg/d (SEM 0.03) for E+, E-, and EN, respectively. Serum prolactin concentrations of heifers grazing E+ were less (P < 0.05) than those grazing E- and EN during all years except yr 2. In yr 2, E+ and E- did not differ (P = 0.11). Serum prolactin of heifers grazing E- and EN did not differ (P > 0.20) except in yr 4. During yr 4, serum prolactin of heifers grazing E- was greater (P = 0.05) than that of heifers grazing EN. Serum urea-N concentrations (SUN) tended to differ among treatments (P = 0.10) and there was a treatment x year interaction (P = 0.05). During yr 1 through 3, SUN did not differ (P > 0.15) among treatments. However, as the stands aged, E- had a greater invasion of other plant species, which increased the CP content of the sward, thus causing heifers grazing E- during yr 5 to have greater (P < 0.01) SUN than heifers grazing E+ and EN, which did not differ (P = 0.89). Forage disappearance (DM basis) did not differ (P = 0.75) among treatments and was 4.7, 4.7, and 5.0 kg/animal daily (SEM 0.27) for E+, E-, and EN, respectively. Body weight gain per hectare was greater (P = 0.04) for E+ (257 kg) than for E- (220 kg) or EN (228 kg). In most years, animal grazing days on E+ were greater than those on E- or EN. However, in yr 5, animal grazing days did not differ (P > 0.20) among treatments. The use of stockpiled E+ as a source of low-cost winter feed is a viable option for producers, whereas grazing of EN may be more beneficial during the spring and fall, when more severe negative effects of ergot alkaloids have been observed. DA - 2009/3// PY - 2009/3// DO - 10.2527/jas.2008-0977 VL - 87 IS - 3 SP - 1034-1041 SN - 1525-3163 KW - endophyte status KW - growing cattle KW - stockpiling KW - tall fescue ER - TY - JOUR TI - Animal and Pasture Productivity of 'Coastal' and 'Tifton 44' Bermudagrass at Three Nitrogen Rates and Associated Soil Nitrogen Status AU - Burns, J. C. AU - Wagger, M. G. AU - Fisher, D. S. T2 - AGRONOMY JOURNAL AB - ‘Coastal’ and ‘Tifton 44’ (T44) bermudagrass [ Cynodon dactylon (L.) Pers.] are well adapted across the lower southern United States, but the grazing response of (T44) to N application in the Piedmont of the upper South warrants further evaluation. This 3‐yr experiment compared animal and pasture productivity of Coastal and T44 with three annual N rates of 101, 202, and 303 kg of N ha −1 on a Cecil clay loam (fine, kaolinitic thermic Typic Kanhapludult) soil typical of the Piedmont. Herbage mass differed for Coastal and T44 (3.5 and 3.0 Mg ha −1 respectively, P < 0.01), but not among N rates. The canopy of T44 was leafier (20.6 vs. 14.5% of dry matter) than Coastal and greater for in vitro true organic matter disappearance (IVTOD) (522 vs. 498 g kg −1 ) and CP (107 vs. 84 g kg −1 ) and lesser in NDF (596 vs. 605 g kg −1 ). The diet selected from T44 was greater in IVTOD (764 vs. 743 g kg −1 ) and lesser in NDF (596 vs. 605 g kg −1 ) giving greater steer average daily gain (0.63 kg vs. 0.57 kg; P < 0.01) which increased ( P = 0.05) with N rate. Weight gain ha −1 (884 kg) and effective feed units (EFU) (4735 kg ha −1 ) were similar, and N rate linearly increased gain from 723 to 1073 kg ha −1 and EFU from 3978 to 5523 kg ha −1 . Soil inorganic N was similar between cultivars but differed among soil depths. Tifton 44 pasture was greater in nutritive value, hence steer performance, and as productive as Coastal in the Piedmont. DA - 2009/// PY - 2009/// DO - 10.2134/agronj2008.0006x VL - 101 IS - 1 SP - 32-40 SN - 0002-1962 ER - TY - JOUR TI - TIMING, LOCATION AND CROP SPECIES INFLUENCE THE MAGNITUDE OF AMELIORATION OF ALUMINUM TOXICITY BY MAGNESIUM AU - Silva, Ivo Ribeiro AU - Cortes Correa, Tarcisio Fernando AU - Novais, Roberto Ferreira AU - Smyth, T. Jot AU - Rufty, Thomas AU - Silva, Eulene Francisco AU - Gebrim, Fabricio Oliveira AU - Nunes, Flancer Novais T2 - REVISTA BRASILEIRA DE CIENCIA DO SOLO AB - The protective effect of cations, especially Ca and Mg, against aluminum (Al) rhizotoxicity has been extensively investigated in the last decades. The mechanisms by which the process occurs are however only beginning to be elucidated. Six experiments were carried out here to characterize the protective effect of Mg application in relation to timing, location and crop specificity: Experiment 1 - Protective effect of Mg compared to Ca; Experiment 2 - Protective effect of Mg on distinct root classes of 15 soybean genotypes; Experiment 3 - Effect of timing of Mg supply on the response of soybean cvs. to Al; Experiment 4 - Investigating whether the Mg protective effect is apoplastic or simplastic using a split-root system; Experiment 5 - Protective effect of Mg supplied in solution or foliar spraying, and Experiment 6 - Protective effect of Mg on Al rhizotoxicity in other crops. It was found that the addition of 50 mmol L-1 Mg to solutions containing toxic Al increased Al tolerance in 15 soybean cultivars. This caused soybean cultivars known as Al-sensitive to behave as if they were tolerant. The protective action of Mg seems to require constant Mg supply in the external medium. Supplying Mg up to 6 h after root exposition to Al was sufficient to maintain normal soybean root growth, but root growth was not recovered by Mg addition 12 h after Al treatments. Mg application to half of the root system not exposed to Al was not sufficient to prevent Al toxicity on the other half exposed to Al without Mg in rooting medium, indicating the existence of an external protection mechanism of Mg. Foliar spraying with Mg also failed to decrease Al toxicity, indicating a possible apoplastic role of Mg. The protective effect of Mg appeared to be soybean-specific since Mg supply did not substantially improve root elongation in sorghum, wheat, corn, cotton, rice, or snap bean when grown in the presence of toxic Al concentrations. DA - 2009/// PY - 2009/// DO - 10.1590/s0100-06832009000100007 VL - 33 IS - 1 SP - 65-76 SN - 0100-0683 KW - soybean KW - cations KW - calcium KW - rhizotoxicity KW - soil acidity ER - TY - JOUR TI - Soil Organic Matter Effects on Phosphorus Sorption: A Path Analysis AU - Kang, Jihoon AU - Hesterberg, Dean AU - Osmond, Deanna L. T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - While P sorption in mineral soils has been extensively studied, P sorption behavior in organic‐rich soils is less known. This study was conducted to determine the relationships between Langmuir P sorption maxima ( S max ) and selected physicochemical properties of soils, with particular emphasis on organic matter (OM) content. The S max values were determined for 72 soil samples from the North Carolina Coastal Plain, along with pH, clay and OM contents, oxalate‐extractable P (P ox ), Al (Al ox ), and Fe (Fe ox ), and Mehlich 3 extractable P (P M3 ), Al (Al M3 ), and Fe (Fe M3 ). Path analysis was used to examine direct and indirect effects of soil properties on S max In the oxalate path analysis, the direct effects of clay, Al ox , and Fe ox on S max were significant in the order Al ox > clay > Fe ox ( P < 0.05). The S max was highly influenced by the indirect effect of Al ox and Fe ox through OM content. A two‐piece segmented linear relationship existed between S max and OM and the regression slope in soils with OM ≤ 49 g kg −1 was 10‐fold greater than that for soils with OM > 49 g kg −1 This finding suggested that noncrystalline or organically bound Al and Fe in the soils with OM > 49 g kg −1 is less effective for P sorption than in the soils with lower OM content. In the Mehlich 3 path analysis, the direct effects of clay, OM, and Al M3 on S max were significant in the order Al M3 > OM > clay ( P < 0.05) while the direct effect of Fe M3 on S max was not significant. Oxalate may be better suited than Mehlich 3 as an extractant for predicting P sorption capacity in the Coastal Plain soils. DA - 2009/// PY - 2009/// DO - 10.2136/sssaj2008.0113 VL - 73 IS - 2 SP - 360-366 SN - 1435-0661 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-62549111344&partnerID=MN8TOARS ER - TY - JOUR TI - Post-Anthesis Moisture Increased Fusarium Head Blight and Deoxynivalenol Levels in North Carolina Winter Wheat AU - Cowger, Christina AU - Patton-Ozkurt, Jennifer AU - Brown-Guedira, Gina AU - Perugini, Leandro T2 - PHYTOPATHOLOGY AB - Current models for forecasting Fusarium head blight (FHB) and deoxynivalenol (DON) levels in wheat are based on weather near anthesis, and breeding for resistance to FHB pathogens often relies on irrigation before and shortly after anthesis to encourage disease development. The effects of post-anthesis environmental conditions on FHB are poorly understood. We performed a field experiment at Kinston, NC, to explore the effects of increasing duration of post-anthesis moisture on disease incidence, disease severity, Fusarium-damaged kernels (FDK), percent infected kernels, and DON. The experiment had a split-plot design, and one trial was conducted in each of two successive years. Main plots consisted of post-anthesis mist durations of 0, 10, 20, or 30 days. Subplots were of eight cultivars in the first year and seven in the second year, two being susceptible to FHB and the remainder each with varying degrees of apparent type I and type II resistance. Plots were inoculated by spraying Fusarium graminearum macroconidia at mid-anthesis. Averaging across years and cultivars, 10 or 20 days of post-anthesis mist had the same effect (P ≥ 0.198) and were associated with an approximately fourfold increase in mean disease incidence and eightfold increase in disease severity compared with 0 days of mist (P ≤ 0.0002). In both years, mean FDK percentages at 0 and 10 days post-anthesis mist were the same and significantly lower than FDK percentages under 20 or 30 days of post-anthesis mist. Mist duration had a significant effect on percent kernels infected with Fusarium spp. as detected by a selective medium assay of 2007 samples. Averaging across all cultivars, in both years, DON levels increased significantly for 10 days compared with 0 days of mist, and increased again with 20 days of mist (P ≤ 0.04). This is the first investigation to show that extended post-flowering moisture can have a significant enhancing effect on FHB, FDK, DON, and percent infected kernels of wheat. For all disease and toxin assays, cultivar rankings were significantly noncorrelated among mist durations in at least 1 year, suggesting that FHB screening programs might rank genotypes differently under extended post-anthesis moisture than without it. Our findings also imply that accurate forecasts of DON in small grains must take account of post-anthesis weather conditions. DA - 2009/4// PY - 2009/4// DO - 10.1094/PHYTO-99-4-0320 VL - 99 IS - 4 SP - 320-327 SN - 0031-949X KW - Gibberella zeae ER - TY - JOUR TI - Effects of total nonstructural carbohydrates and nitrogen balance on voluntary intake of goats and digestibility of gamagrass hay harvested at sunrise and sunset AU - Sauve, A. K. AU - Huntington, G. B. AU - Burns, J. C. T2 - ANIMAL FEED SCIENCE AND TECHNOLOGY AB - Abstract We evaluated differences in composition of Iuka gamagrass ( Tripsacum dactyloides L.) hay harvested at 06:00 (AM harvest) or 18:00 h (PM harvest), and measured how protein supplementation and time of harvest interact to affect the voluntary intake, digestibility, and N balance of goats. Boer cross wethers ( n  = 28; 24 kg) were randomly assigned to be fed supplement (310 g/kg of crude protein (CP), fed at 110 g/kg of dry matter (DM) intake, 14 goats) or no supplement (14 goats). Within supplemented or not supplemented groups, goats were randomly assigned to a crossover design of AM harvest (seven goats) or PM harvest (seven goats), and housed individually in metabolism crates with free access to water and mineral blocks. They were fed twice daily, with supplement offered 30 min prior to the morning feedings. After a 7-d adaptation, voluntary intake (goats were offered 1100 g/kg of previous day's intake) was measured for 14 d, followed by a 4-d adjustment phase to equalize DM offered between periods, and finally a 5-d digestion and balance phase. After Period 1, goats were switched to their new hay harvest times, and the protocol was repeated. Compared to the AM harvest, the PM harvest had higher (P versus 59.0 g/kg DM), monosaccharides (37.0 g/kg DM versus 28.6 g/kg DM), di- and polysaccharides (18.5 g/kg DM versus 15.4 g/kg DM) and less neutral detergent fiber (NDF, 700 g/kg versus 710 g/kg). Crude protein (79 g/kg DM) and starch (15.2 g/kg DM) were similar for the PM and AM harvest. Dry matter digestibility was higher (P versus AM harvests (555 g/kg DM versus 531 g/kg DM) and for supplemented versus not supplemented (563 g/kg DM versus 522 g/kg DM). Voluntary gamagrass DM intake (550 g/d versus 548 g/d) and calculated total digestible DM intake (327 g/d versus 313 g/d) were similar for the PM and AM harvest. However, total digestible DM intake during the digestion and balance phase was higher (P versus AM harvest (317 g/d versus 299 g/d). Time of harvest did not affect N intake, digestion, or calculated retention. Compared to no supplementation, the supplement improved (P versus 3.7 g/d) and retention (2.2 g/d versus 1.1 g/d). The PM harvest increased DM digested, largely TNC and digestible DM intake by goats due to increased TNC and not because of a 2% increase in DM intake. Providing a protein supplement had very limited effects on intake and digestibility of gamagrass. DA - 2009/1/16/ PY - 2009/1/16/ DO - 10.1016/j.anifeedsci.2008.03.001 VL - 148 IS - 2-4 SP - 93-106 SN - 1873-2216 KW - Goats KW - Gamagrass hay KW - Nonstructural carbohydrates KW - N metabolism ER - TY - JOUR TI - Urea metabolism in beef steers fed tall fescue, orchardgrass, or gamagrass hays AU - Huntington, G. B. AU - Magee, K. AU - Matthews, A. AU - Poore, M. AU - Burns, J. T2 - JOURNAL OF ANIMAL SCIENCE AB - Two experiments were conducted to assess effects of endophyte treatments (Exp. 1), forage species (Exp. 2), and supplementation (Exp. 2) on urea production, excretion, and recycling in beef steers. Infusion of 15,15N-urea and enrichment of urea in urine samples were used to calculate urea-N entry and recycling to the gut. Acceptably stable enrichment of 15N-urea in urine was obtained after 50 h of intrajugular infusion of 15,15N-urea, indicating that valid data on urea metabolism can be obtained from steers fed forages twice daily. After adjustment by covariance for differences in N intake among treatments in Exp. 1, steers fed endophyte-infected tall fescue had less (P < 0.10) urea-N entry, recycling to the gut, and return of recycled urea-N to the ornithine cycle than those fed endophyte-free or novel endophyte-infected tall fescue. However, urea-N urinary excretion or return to the gut was similar among endophyte treatments when expressed as a proportion of urea-N entry. Urea-N entry and return to the gut in Exp. 2 was similar in steers fed gamagrass or orchardgrass hay after adjustment by covariance for differences in N intake. Less (P < 0.01) urinary excretion, expressed as grams per day or as a proportion of urea-N entry, with gamagrass than with orchardgrass was associated with faster in vitro NDF-N digestion with gamagrass. Supplementation of gamagrass or orchardgrass with 1.76 kg/d of readily fermentable fiber and starch decreased urea entry (P < 0.06) and urinary excretion of urea (P < 0.01). Interactions between hay source and supplement reflected a greater response to supplementation for steers fed orchardgrass than for those fed gamagrass. After adjustment for differences among treatments in N supply, results of both experiments support the concept of improved N use in response to increased carbohydrate fermentability in the rumen, due either to inherent differences in forage fiber or to supplementation with readily fermentable carbohydrate (starch or fiber). Closer coordination of ruminal fermentation of carbohydrate and N sources provided greater and more efficient capture of dietary N as tissue protein in forage-fed steers. DA - 2009/4// PY - 2009/4// DO - 10.2527/jas.2008-1444 VL - 87 IS - 4 SP - 1346-1353 SN - 1525-3163 KW - fescue KW - gamagrass KW - orchardgrass KW - steer KW - urea metabolism ER - TY - JOUR TI - Protamine-mediated DNA coating remarkably improves bombardment transformation efficiency in plant cells AU - Sivamani, Elumalai AU - DeLong, Robert K. AU - Qu, Rongda T2 - PLANT CELL REPORTS DA - 2009/2// PY - 2009/2// DO - 10.1007/s00299-008-0636-4 VL - 28 IS - 2 SP - 213-221 SN - 1432-203X KW - DNA coating KW - DNA delivery KW - GUS KW - Plant transformation KW - Particle bombardment KW - Protamine ER - TY - JOUR TI - A new model of bi-directional ammonia exchange between the atmosphere and biosphere: Ammonia stomatal compensation point AU - Wu, Yihua AU - Walker, John AU - Schwede, Donna AU - Peters-Lidard, Christa AU - Dennis, Robin AU - Robarge, Wayne T2 - AGRICULTURAL AND FOREST METEOROLOGY AB - A new multi-layer canopy resistance model of bi-directional NH3 exchange is presented. This new model, which is based on the Multi-Layer BioChemical deposition (MLBC) model [Wu, Y., Brashers, B., Finkelstein, P.L., Pleim, J.E., 2003a. A multiplayer biochemical dry deposition model. I. Model formulation. J. Geophys. Res. 108, D1; Wu, Y., Brashers, B., Finkelstein, P.L., Pleim, J.E., 2003b. A multiplayer biochemical dry deposition model. II. Model evaluation. J. Geophys. Res. 108, D1], incorporates a parameterization for the ammonia stomatal compensation point that is theoretically derived to consider the effects of leaf temperature and apoplastic concentrations of NH4+ and H+. The new ammonia stomatal compensation point scheme accounts for the effects of deposition, emission and leaf temperature on the dynamics of apoplast [NH4+] and [H+]. The new model is evaluated against bidirectional NH3 fluxes measured over fertilized soybean. The general patterns of observed deposition and emission are successfully reproduced when the ammonia stomatal compensation point is included. Driven by the effects of deposition, emission and leaf temperature, modeled apoplastic [NH4+] and [H+] display significant diurnal variation when the buffer effect of the underlying metabolic processes generating or consuming NH4+ were ignored. Model predictive capability is improved slightly by incorporating the feedback into a dynamic stomatal compensation point. A simple implementation of the feedback mechanism in the current model provides opportunities for improvement. While the stomatal flux is shown to be an important process in the regulation of canopy-scale fluxes, it appears that exchange with leaf surface water and soil may also be important. DA - 2009/2// PY - 2009/2// DO - 10.1016/j.agrformet.2008.08.012 VL - 149 IS - 2 SP - 263-280 SN - 1873-2240 KW - Ammonia KW - Deposition KW - Emission KW - Compensation point KW - Modeling KW - Bi-directional flux KW - Soybean ER - TY - PCOMM TI - Simulation of winter wheat evapotranspiration in Texas and Henan using three models of differing complexity AU - Kang, Shujiang AU - Evett, Steven R. AU - Robinson, Clay A. AU - Stewart, Bobby A. AU - Payne, William A. AB - Crop evapotranspiration (ET) is an important component of simulation models with many practical applications related to the efficient management of crop water supply. The algorithms used by models to calculate ET are of various complexity and robustness, and often have to be modified for particular environments. We chose three crop models with different ET calculation strategies: CROPWAT with simple data inputs and no calibrations, MODWht for intensive inputs and limited calibrations, and CERES-Wheat with intensive inputs and more calibrations for parameters. The three crop models were used to calculate ET of winter wheat (Triticum aestivum L.) grown at two experimental sites of China and US during multiple growing seasons in which ET was measured using lysimeter or soil water balance techniques. None of the models calculated daily ET well at either Bushland or Zhengzhou as indicated by high mean absolute differences (MAD > 1.1 mm) and root mean squared errors (RMSE > 2.0 mm). The three models tended to overestimate daily ET when measured ET was small, and to underestimate daily ET when measured ET was large. The fitted values of daily crop coefficients (Kc), calculated from daily ET and reference ET (ETo), were very similar to those of Allen et al. (1998) [Allen, R.G., Pereira, S.L., Raes, D., Smith, M., 1998. Crop evapotranspiration guidelines for computing crop water requirements. Irrigation and drainage paper 56, Rome] although some Kc were overestimated (≥1.0). Leaf area index (LAI) was poorly calculated by MODWht and CERES-Wheat, especially when using the Priestley–Taylor method to estimate potential ET (PET). Poor overall ET calculation of three models was associated with poorly estimated values of PET or ETo, Kc and LAI as well as their interactions. Therefore, this suggested that considerable revisions and calibrations of ET algorithms of the three models are needed for the improvement of ET calculation. DA - 2009/1// PY - 2009/1// DO - 10.1016/j.agwat.2008.07.006 SP - 167-178 KW - Evapotranspiration KW - Crop model KW - Winter wheat ER - TY - JOUR TI - Mapping candidate genes for oleate biosynthesis and their association with unsaturated fatty acid seed content in soybean AU - Bachlava, Eleni AU - Dewey, Ralph E. AU - Burton, Joseph W. AU - Cardinal, Andrea J. T2 - MOLECULAR BREEDING DA - 2009/2// PY - 2009/2// DO - 10.1007/s11032-008-9246-7 VL - 23 IS - 2 SP - 337-347 SN - 1572-9788 KW - Soybean KW - Oleate biosynthesis KW - QTL mapping KW - Fatty acid content ER - TY - JOUR TI - Enhanced litter input rather than changes in litter chemistry drive soil carbon and nitrogen cycles under elevated CO2: a microcosm study AU - Liu, Lingli AU - King, John S. AU - Booker, Fitzgerald L. AU - Giardina, Christian P. AU - Allen, H. Lee AU - Hu, Shuijin T2 - GLOBAL CHANGE BIOLOGY AB - Abstract Elevated CO 2 has been shown to stimulate plant productivity and change litter chemistry. These changes in substrate availability may then alter soil microbial processes and possibly lead to feedback effects on N availability. However, the strength of this feedback, and even its direction, remains unknown. Further, uncertainty remains whether sustained increases in net primary productivity will lead to increased long‐term C storage in soil. To examine how changes in litter chemistry and productivity under elevated CO 2 influence microbial activity and soil C formation, we conducted a 230‐day microcosm incubation with five levels of litter addition rate that represented 0, 0.5, 1.0, 1.4 and 1.8 × litterfall rates observed in the field for aspen stand growing under control treatments at the Aspen FACE experiment in Rhinelander, WI, USA. Litter and soil samples were collected from the corresponding field control and elevated CO 2 treatment after trees were exposed to elevated CO 2 (560 ppm) for 7 years. We found that small decreases in litter [N] under elevated CO 2 had minor effects on microbial biomass carbon, microbial biomass nitrogen and dissolved inorganic nitrogen. Increasing litter addition rates resulted in linear increase in total C and new C (C from added litter) that accumulated in whole soil as well as in the high density soil fraction (HDF), despite higher cumulative C loss by respiration. Total N retained in whole soil and in HDF also increased with litter addition rate as did accumulation of new C per unit of accumulated N. Based on our microcosm comparisons and regression models, we expected that enhanced C inputs rather than changes in litter chemistry would be the dominant factor controlling soil C levels and turnover at the current level of litter production rate (230 g C m −2 yr −1 under ambient CO 2 ). However, our analysis also suggests that the effects of changes in biochemistry caused by elevated CO 2 could become significant at a higher level of litter production rate, with a trend of decreasing total C in HDF, new C in whole soil, as well as total N in whole soil and HDF. DA - 2009/2// PY - 2009/2// DO - 10.1111/j.1365-2486.2008.01747.x VL - 15 IS - 2 SP - 441-453 SN - 1365-2486 KW - delta C-13 KW - decomposition KW - DIN KW - EMMA KW - global change KW - MBC KW - MBN KW - new soil C KW - old soil C KW - stable isotope ER - TY - JOUR TI - Quantitative Structure-Activity Relationships for Aqueous Metal-Siderophore Complexes AU - Duckworth, Owen W. AU - Bargar, John R. AU - Sposito, Garrison T2 - ENVIRONMENTAL SCIENCE & TECHNOLOGY AB - Siderophores, biogenic chelating agents that facilitate the solubilization and uptake of ferric iron, form stable complexes with a wide range of nutrient and contaminant metals and thus may profoundly affect their fate, transport, and biogeochemical cycling. To understand more comprehensively the factors that control the stability and reactivity, as well as the potential for microbial uptake, of metal−siderophore complexes, we probed the structures of complexes formed between the trihydroxamate siderophore desferrioxamine B (DFOB) and Cu(II), Ga(III), Mn(II), Ni(II), and Zn(II) in solution by using extended X-ray absorption fine structure (EXAFS) spectroscopy. We find that all metals studied are dominantly in octahedral coordination, with significant Jahn−Teller distortion of the Cu(II)HDFOB0 complex. Additionally, log-transformed complex stability constants correlate not only with the charge-normalized interatomic distances within the complex, affirming and expanding existing predictive relationships, but also with the Debye−Waller parameter of the first coordination shell. The derived structure−activity relationships not only quantitatively relate the measured physical architecture of aqueous complexes to their observed stability but also allow for the prediction of siderophore−metal stability constants. DA - 2009/1/15/ PY - 2009/1/15/ DO - 10.1021/es802044y VL - 43 IS - 2 SP - 343-349 SN - 1520-5851 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-60949097462&partnerID=MN8TOARS ER - TY - JOUR TI - Isolation of expressed sequences from a specific chromosome of Thinopyrum intermedium infected by BYDV AU - Jiang, Shu-Mei AU - Yin, Wei-Bo AU - Hu, Jun AU - Shi, Rui AU - Zhou, Ruo-Nan AU - Chen, Yu-Hong AU - Zhou, Guang-He AU - Wang, Richard R. -C. AU - Song, Li-Ying AU - Hu, Zan-Min T2 - GENOME AB - To map important ESTs to specific chromosomes and (or) chromosomal regions is difficult in hexaploid wheat because of its large genome size and serious interference of homoeologous sequences. Large-scale EST sequencing and subsequent chromosome localization are both laborious and time-consuming. The wheat alien addition line TAi-27 contains a pair of chromosomes of Thinopyrum intermedium (Host) Barkworth & D.R. Dewey that carry the resistance gene against barley yellow dwarf virus. In this research, we developed a modified technique based on chromosome microdissection and hybridization-specific amplification to isolate expressed sequences from the alien chromosome of TAi-27 by hybridization between the DNA of the microdissected alien chromosome and cDNA of Th. intermedium infected by barley yellow dwarf virus. Twelve clones were selected, sequenced, and analyzed. Three of them were unknown genes without any hit in the GenBank database and the other nine were highly homologous with ESTs of wheat, barley, and (or) other plants in Gramineae induced by abiotic or biotic stress. The method used in this research to isolate expressed sequences from a specific chromosome has the following advantages: (i) the obtained expressed sequences are larger in size and have 3′ end information and (ii) the operation is less complicated. It would be an efficient improved method for genomics and functional genomics research of polyploid plants, especially for EST development and mapping. The obtained expressed sequence data are also informative in understanding the resistance genes on the alien chromosome of TAi-27. DA - 2009/1// PY - 2009/1// DO - 10.1139/G08-108 VL - 52 IS - 1 SP - 68-76 SN - 1480-3321 KW - TAi-27 KW - Thinopyrum intermedium KW - chromosome microdissection KW - hybridization-specific amplification (HSA) KW - expressed sequences KW - barley yellow dwarf virus (BYDV) ER - TY - JOUR TI - Freezing in non-acclimated oats. II: Thermal response and histology of recovery in gradual and rapidly frozen plants AU - Livingston, David P., III AU - Tallury, Shyamalrau P. T2 - THERMOCHIMICA ACTA AB - Freezing in winter cereals is a complex phenomenon that can affect various plant tissues differently. To better understand how freezing affects specific tissue in the over wintering organ (crown) of winter cereal crops, non-acclimated oats (Avena sativa L.) were gradually frozen to −3 °C and tissue damage during recovery was compared to plants that had been supercooled to −3 °C and then frozen suddenly. Percentage of total water frozen, was the same whether crowns were frozen suddenly or gradually although the rate of freezing was considerably different. For example, all available water froze within 3 h in suddenly frozen crowns but it took more than 15 h for all available water to freeze in gradually frozen crowns. When plants were suddenly frozen, cells in the apical meristem were disrupted and apparently killed. In these plants re-growth was limited or non-existent. In contrast, the apical region of plants that were slowly frozen appeared undamaged but extensive vessel plugging was observed in cells of the lower crown, possibly from accumulation of phenolics or from microbial proliferation. These histological observations along with the calorimetric analysis suggested that the apical region was killed by intracellular freezing when frozen suddenly while the crown core was damaged by a process, which either induced production of putative phenolic compounds by the plant and/or permitted what appeared to be microbial proliferation in metaxylem vessels. DA - 2009/1/5/ PY - 2009/1/5/ DO - 10.1016/j.tca.2008.09.024 VL - 481 IS - 1-2 SP - 20-27 SN - 1872-762X KW - Freezing tolerance KW - Oats KW - Avena sativa KW - Super cooling KW - Latent heat KW - Isothermal calorimeter KW - Histology KW - Triple stain KW - Paraffin embedding KW - Apical meristem KW - Crown core ER - TY - JOUR TI - Absorption, Translocation, and Metabolism of C-14-Glufosinate in Glufosinate-Resistant Corn, Goosegrass (Eleusine indica), Large Crabgrass (Digitaria sanguinalis), and Sicklepod (Senna obtusifolia) AU - Everman, Wesley J. AU - Mayhew, Cassandra R. AU - Burton, James D. AU - York, Alan C. AU - Wilcut, John W. T2 - WEED SCIENCE AB - Greenhouse studies were conducted to evaluate 14 C-glufosinate absorption, translocation, and metabolism in glufosinate-resistant corn, goosegrass, large crabgrass, and sicklepod. Glufosinate-resistant corn plants were treated at the four-leaf stage, whereas goosegrass, large crabgrass, and sicklepod were treated at 5, 7.5, and 10 cm, respectively. All plants were harvested at 1, 6, 24, 48, and 72 h after treatment (HAT). Absorption was less than 20% at all harvest intervals for glufosinate-resistant corn, whereas absorption in goosegrass and large crabgrass increased from approximately 20% 1 HAT to 50 and 76%, respectively, 72 HAT. Absorption of 14 C-glufosinate was greater than 90% 24 HAT in sicklepod. Significant levels of translocation were observed in glufosinate-resistant corn, with 14 C-glufosinate translocated to the region above the treated leaf and the roots up to 41 and 27%, respectively. No significant translocation was detected in any of the weed species at any harvest timing. Metabolites of 14 C-glufosinate were detected in glufosinate-resistant corn and all weed species. Seventy percent of 14 C was attributed to glufosinate metabolites 72 HAT in large crabgrass. Less metabolism was observed for sicklepod, goosegrass, and glufosinate-resistant corn, with metabolites composing less than 45% of detectable radioactivity 72 HAT. DA - 2009/// PY - 2009/// DO - 10.1614/WS-08-089.1 VL - 57 IS - 1 SP - 1-5 SN - 1550-2759 KW - Absorption KW - corn KW - glufosinate KW - metabolism KW - translocation ER -