TY - RPRT TI - How much water does a golf course operator need? AU - Miller, G.L. AU - Pressler, N. AU - Mitchell, M. DA - 2004/// PY - 2004/// SP - 15 ER - TY - SOUND TI - Reducing residential irrigation water use in Florida AU - Dukes, M.D. AU - Haley, M.B. AU - Miller, G.L. DA - 2004/11/14/ PY - 2004/11/14/ ER - TY - SOUND TI - Comparison of irrigation uniformity by soil moisture to catch can test AU - Baum, M.C. AU - Dukes, M.D. AU - Miller, G.L. DA - 2004/6/2/ PY - 2004/6/2/ ER - TY - RPRT TI - Athletic field use capacity AU - Miller, G.L. A3 - University of Florida DA - 2004/// PY - 2004/// M1 - ENH-991 M3 - University of Florida IFAS Extension Publication PB - University of Florida SN - ENH-991 ER - TY - RPRT TI - Comparison of irrigation uniformity by soil moisture to catch-can test AU - Baum, M.C. AU - Dukes, M.D. AU - Miller, G.L. A3 - American Society of Agricultural Engineers DA - 2004/// PY - 2004/// M1 - FL04-1011 M3 - ASAE Paper PB - American Society of Agricultural Engineers SN - FL04-1011 ER - TY - SOUND TI - Comparison of turfgrass culture of Italy and Florida AU - Miller, G.L. DA - 2004/5/3/ PY - 2004/5/3/ ER - TY - SOUND TI - Reducing residential irrigation water use in Florida AU - Dukes, M.D. AU - Baum, M.C. AU - Miller, G.L. DA - 2004/11/14/ PY - 2004/11/14/ ER - TY - SOUND TI - Turf and Sports AU - Miller, G.L. DA - 2004/10/25/ PY - 2004/10/25/ ER - TY - SOUND TI - Management of Baseball fields AU - Miller, G.L. DA - 2004/10/7/ PY - 2004/10/7/ M3 - guest lecture ER - TY - SOUND TI - Turf and Sports AU - Miller, G.L. DA - 2004/7/27/ PY - 2004/7/27/ ER - TY - SOUND TI - Managing Grasses for Landscape and Recreational Uses AU - Miller, G.L. DA - 2004/2/17/ PY - 2004/2/17/ ER - TY - SOUND TI - Turf and Sports AU - Miller, G.L. DA - 2004/1/22/ PY - 2004/1/22/ ER - TY - SOUND TI - Giving Professional Presentations AU - Miller, G.L. DA - 2004/12// PY - 2004/12// ER - TY - SOUND TI - Cultural Practices for Athletic Fields AU - Miller, Grady DA - 2004/6/11/ PY - 2004/6/11/ ER - TY - SOUND TI - Envirotron Research Update AU - Miller, Grady DA - 2004/7/22/ PY - 2004/7/22/ ER - TY - SOUND TI - How to get the most bang for the buck: Proper Calibration of Equipment AU - Miller, Grady DA - 2004/4/28/ PY - 2004/4/28/ ER - TY - SOUND TI - Transitioning Athletic Fields AU - Miller, Grady L. DA - 2004/8/17/ PY - 2004/8/17/ ER - TY - SOUND TI - Sports Field Construction AU - Miller, Grady DA - 2004/3/25/ PY - 2004/3/25/ ER - TY - SOUND TI - Basic Weed ID and Control in athletic fields. AU - Miller, Grady DA - 2004/3/25/ PY - 2004/3/25/ ER - TY - SOUND TI - Influence of Field Aerification on Weed Control AU - Miller, Grady DA - 2004/1/5/ PY - 2004/1/5/ ER - TY - SOUND TI - An evaluation of Olympic Stadium AU - Miller, G.L. DA - 2004/5/5/ PY - 2004/5/5/ ER - TY - JOUR TI - Tips on pesticide efficacy, formulations, and application equipment AU - Buss, E.A. AU - Miller, G.L. T2 - Golf Advantage DA - 2004/// PY - 2004/// VL - 2 IS - 2 SP - 20-21 ER - TY - JOUR TI - Make safety a priority: what you should know about personal protection equipment and post application AU - Miller, G.L. AU - Buss, E.A. T2 - Golf Advantage DA - 2004/// PY - 2004/// VL - 2 IS - 1 SP - 27-28 ER - TY - JOUR TI - The Doctor of Plant Medicine program takes root in UF/IFAS AU - Stiles, C.M. AU - Miller, G.L. AU - McGovern, R.J. T2 - Florida Turf Digest DA - 2004/// PY - 2004/// VL - 21 IS - 5 SP - 22-24 ER - TY - JOUR TI - Overseeding trials in Gainesville AU - Miller, G.L. T2 - Florida Turf Digest DA - 2004/// PY - 2004/// VL - 21 IS - 5 SP - 10-12 ER - TY - JOUR TI - Turf team gains one, loses two AU - Miller, G.L. T2 - Florida Turf Digest DA - 2004/// PY - 2004/// VL - 21 IS - 4 SP - 25 ER - TY - JOUR TI - Irrigation scheduling and uniformity AU - Miller, G.L. AU - Pressler, N. T2 - Florida Turf Digest DA - 2004/// PY - 2004/// VL - 21 IS - 2 SP - 20-22 ER - TY - JOUR TI - IFAS adds plant pathologist for extension, research AU - Stiles, C.M. AU - Miller, G.L. T2 - Florida Turf Digest DA - 2004/// PY - 2004/// VL - 21 IS - 1 SP - 22–23 ER - TY - SOUND TI - Water use on Florida’s Golf Courses AU - Miller, Grady DA - 2004/5/28/ PY - 2004/5/28/ ER - TY - CONF TI - Student Recruitment and Involvement Beyond the Classroom AU - Liu, H. AU - Miller, G.L. T2 - Southern Extension and Research Association Meeting C2 - 2004/6/8/ CY - Pensacola Beach, FL DA - 2004/6/8/ PY - 2004/6/8/ ER - TY - SOUND TI - Plant Nutrition and Fertilization AU - Miller, G.L. AU - Frank, K. DA - 2004/11/10/ PY - 2004/11/10/ ER - TY - CONF TI - Wear and Tear Mapping AU - Miller, Grady T2 - Alabama Turfgrass Conference C2 - 2004/10/27/ CY - Auburn, AL DA - 2004/10/27/ PY - 2004/10/27/ ER - TY - CONF TI - Transitioning Overseeded Bermudagrass AU - Miller, G.L. T2 - SEC Sports Turf Managers Conference C2 - 2004/6/18/ CY - Athens, GA DA - 2004/6/18/ PY - 2004/6/18/ ER - TY - SOUND TI - Transitioning Overseeded Bermudagrass AU - Miller, G.L. DA - 2004/6/18/ PY - 2004/6/18/ ER - TY - CONF TI - Plant Nutrition and Fertilizers: Part 2 AU - Miller, G.L. AU - Rieke, P.E. T2 - 75th Annual International Golf Course Conference and Show C2 - 2004/2/12/ CY - San Diego, CA DA - 2004/2/12/ PY - 2004/2/12/ ER - TY - CONF TI - Plant Nutrition and Fertilizers: Part 1 AU - Miller, G.L. AU - Rieke, P.E. T2 - 75th Annual International Golf Course Conference and Show C2 - 2004/2/11/ CY - San Diego, CA DA - 2004/2/11/ PY - 2004/2/11/ ER - TY - CONF TI - Use of bermudagrass in Mediterranean climates [Specie macroterme per tappeti erbosi sportivi] AU - Miller, G.L. T2 - Special conference on athletic field management C2 - 2004/5/8/ CY - Lecce, Italy DA - 2004/5/8/ PY - 2004/5/8/ ER - TY - JOUR TI - Finally, physics class is useful AU - Miller, G.L. T2 - SportsTurf DA - 2004/// PY - 2004/// VL - 12 IS - 12 SP - 42 ER - TY - JOUR TI - Establishing bermudagrass AU - Miller, G.L. T2 - SportsTurf DA - 2004/// PY - 2004/// VL - 20 IS - 8 SP - 42 ER - TY - JOUR TI - Changing your spots AU - Miller, G.L. T2 - SportsTurf DA - 2004/// PY - 2004/// VL - 20 IS - 6 SP - 46 ER - TY - JOUR TI - Ryegrass on southern athletic fields AU - Miller, G.L. T2 - SportsTurf DA - 2004/// PY - 2004/// VL - 20 IS - 2 SP - 46 ER - TY - SOUND TI - Modern Turfgrass Culture in the US AU - Miller, G.L. DA - 2004/// PY - 2004/// PB - University of Pisa ER - TY - SOUND TI - Turfgrass Research in Florida AU - Miller, G.L. DA - 2004/// PY - 2004/// ER - TY - SOUND TI - Evaluation of sensor-based control of irrigation in Bermudagrass AU - Miller, G DA - 2004/7/22/ PY - 2004/7/22/ ER - TY - SOUND TI - Determination of residential irrigation water use in Florida. AU - Miller, Grady DA - 2004/7/22/ PY - 2004/7/22/ ER - TY - JOUR TI - Revegetation of Waste Fly Ash Landfills in a Semiarid Environment AU - Pierzynski, Gary M. AU - Heitman, Joshua L. AU - Kulakow, Peter A. AU - Kluitenberg, Gerard J. AU - Carlson, James T2 - Journal of Range Management DA - 2004/5// PY - 2004/5// DO - 10.2307/4003801 VL - 57 IS - 3 SP - 312 J2 - Journal of Range Management OP - SN - 0022-409X UR - http://dx.doi.org/10.2307/4003801 DB - Crossref KW - salinity KW - plant nutrients KW - germination KW - available water capacity ER - TY - CONF TI - Determination of Residential Irrigation Water Use in Florida AU - Dukes, Michael D. AU - Baum, Melissa C. AU - Miller, Grady L. T2 - World Water and Environmental Resources Congress 2004 AB - Residential irrigation water use is a large component of total water use in Florida. With one of the largest state populations in the U.S. that is rapidly growing, competition between urban, agricultural, and other water users is increasing. This project measured residential irrigation water use and irrigation system uniformities in central Florida. Three treatments were established as follows: typical irrigation practices (T1), irrigation based on historical evapotranspiration (T2), and water wise landscape plus irrigation designed to minimize water use (T3). T1 homes averaged 143 mm of irrigation per month in 2003 while T2 and T3 averaged 103 and 74 mm, respectively. This corresponds to a 28 and 48% reduction in irrigation water use compared to the typical practices, respectively. Distribution uniformity (DU1q) of homes tested averaged 0.40–0.50 which was statistically lower than irrigation heads tested under controlled conditions and also lower than industry standards. The preliminary results indicate that design for uniform application of water is difficult in small non-uniform areas of residential yards with current commercially available equipment and that irrigation water use can be reduced by proper scheduling and with landscapes that are designed to minimize irrigation. C2 - 2004/6/25/ C3 - Critical Transitions in Water and Environmental Resources Management CY - Salt Lake City, UT DA - 2004/6/25/ PY - 2004/6/27/ DO - 10.1061/40737(2004)225 PB - American Society of Civil Engineers SN - 9780784407370 UR - http://dx.doi.org/10.1061/40737(2004)225 DB - Crossref ER - TY - JOUR TI - Estrogen Content of Dairy and Swine Wastes AU - Raman, D. Raj AU - Williams, Elizabeth L. AU - Layton, Alice C. AU - Burns, Robert T. AU - Easter, James P. AU - Daugherty, Adam S. AU - Mullen, Michael D. AU - Sayler, Gary S. T2 - Environmental Science & Technology AB - Naturally occurring estrogens in animal wastes may cause negative environmental impacts, yet their abundance in animal waste treatment and storage structures is poorly documented. To better quantify estrogen concentrations in animal wastes, multiple waste samples were collected from treatment and storage structures at dairy and swine facilities and analyzed for concentrations of 17beta-estradiol (E2), estrone (E1), and 17alpha-estradiol by gas chromatography-mass spectroscopy and by enzyme linked immunosorbent assay (E2 only). Mass ratios of each estrogen to the macronutrients nitrogen, phosphorus, and potassium were also determined. Because manure application rates are typically macronutrient-based, estrogen to macronutrient ratios are proportional to areal mass application rates of estrogen to fields. Swine farrowing waste (from farrowing sows and piglets) had the highest ratios of E2 to macronutrients. Mean ratios in swine farrowing waste were roughly twice those in swine finishing waste (from growing male and nonpregnant female animals) and more than four times higher than those in dairy waste (from lactating cows in various stages of their reproductive cycles); these differences were statistically significant (alpha = 0.05). Estrone followed a similar trend. In contrast, ratios of 17alpha-estradiol to macronutrients were highest in dairy operations. These results can be used to better predict estrogen loading rates on fields receiving swine and dairy wastes. DA - 2004/7// PY - 2004/7// DO - 10.1021/es0353208 VL - 38 IS - 13 SP - 3567-3573 J2 - Environ. Sci. Technol. LA - en OP - SN - 0013-936X 1520-5851 UR - http://dx.doi.org/10.1021/es0353208 DB - Crossref ER - TY - JOUR TI - Role of molecular oxygen in the dissolution of siderite and rhodochrosite AU - Duckworth, Owen W AU - Martin, Scot T T2 - Geochimica et Cosmochimica Acta AB - The dissolution of siderite (FeCO3) and rhodochrosite (MnCO3) under oxic and anoxic conditions is investigated at 298 K. The anoxic dissolution rate of siderite is 10−8.65 mol m−2 s−1 for 5.5 < pH < 12 and increases as [H+]0.75 for pH < 5.5. The pH dependence is consistent with parallel proton-promoted and water hydrolysis dissolution pathways. Atomic force microscopy (AFM) reveals a change in pit morphology from rhombohedral pits for pH > 4 to pits elongated at one vertex for pH < 4. Under oxic conditions the dissolution rate decreases to below the detection limit of 10−10 mol m−2 s−1 for 6.0 < pH < 10.3, and hillock precipitation preferential to steps is observed in concurrent AFM micrographs. X-ray photoelectron spectroscopy (XPS) and thermodynamic analysis identify the precipitate as ferrihydrite. At pH > 10.3, the oxic dissolution rate is as high as 10−7.5 mol m−2 s−1, which is greater than under the corresponding anoxic conditions. A fast electron transfer reaction between solution O2 or [Fe3+(OH)4]− species and surficial >FeII hydroxyl groups is hypothesized to explain the dissolution kinetics. AFM micrographs do not show precipitation under these conditions. Anoxic dissolution of rhodochrosite is physically observed as rhombohedral pit expansion for 3.7 < pH < 10.3 and is chemically explained by parallel proton- and water-promoted pathways. The dissolution rate law is 10−4.93[H+] + 10−8.45 mol m−2 s−1. For 5.8 < pH < 7.7 under oxic conditions, the AFM micrographs show a tabular precipitate growing by preferential expansion along the a-axis, though the macroscopic dissolution rate is apparently unaffected. For pH > 7.7 under oxic conditions, the dissolution rate decreases from 10−8.45 to 10−9.0 mol m−2 s−1. Flattened hillock precipitates grow across the entire surface without apparent morphological influence by the underlying rhodochrosite surface. XPS spectra and thermodynamic calculations implicate the precipitate as bixbyite for 5.8 < pH < 7.7 and MnOOH (possibly feitnkechtite) for pH >7.7. DA - 2004/2// PY - 2004/2// DO - 10.1016/S0016-7037(03)00464-2 VL - 68 IS - 3 SP - 607-621 J2 - Geochimica et Cosmochimica Acta LA - en OP - SN - 0016-7037 UR - http://dx.doi.org/10.1016/S0016-7037(03)00464-2 DB - Crossref ER - TY - JOUR TI - Weed control and potato (Solanum tuberosum) tolerance with dimethenamid isomers and other herbicides AU - Richardson, Robert J. AU - Whaley, Cory M. AU - Wilson, Henry P. AU - Hines, Thomas E. T2 - American Journal of Potato Research DA - 2004/9// PY - 2004/9// DO - 10.1007/bf02870175 VL - 81 IS - 5 SP - 299-304 J2 - Am. J. Pot Res LA - en OP - SN - 1099-209X 1874-9380 UR - http://dx.doi.org/10.1007/bf02870175 DB - Crossref KW - common lambsquarters KW - common ragweed KW - goosegrass KW - large crabgrass KW - weed control ER - TY - CONF TI - Effect of graywater on soil hydraulic properties AU - Amoozegar, A. AU - Warren, S. AU - Niewoehner, C. AU - Robarge, W. AU - Hoover, M. AU - Hesterberg, D. AU - Rubin, R. C2 - 2004/// C3 - Proceedings of the 10th National Symposium on Individual and Small Community Sewage Systems - On-Site Wastewater Treatment X DA - 2004/// SP - 231-240 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-27944473100&partnerID=MN8TOARS ER - TY - JOUR TI - Examination of backfill materials for high-level waste repository AU - McKinney, D.S. AU - Yim, M.-S. AU - Hesterberg, D. T2 - Technology DA - 2004/// PY - 2004/// VL - 9 IS - 4 SP - 187-194 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-4544384119&partnerID=MN8TOARS ER - TY - JOUR TI - Analysis of soccer field surface hardness AU - Miller, G.L. T2 - Acta Horticulturae DA - 2004/11// PY - 2004/11// DO - 10.17660/actahortic.2004.661.36 VL - 661 IS - 661 SP - 287-294 SN - 0567-7572 2406-6168 UR - http://dx.doi.org/10.17660/actahortic.2004.661.36 KW - spatial analysis KW - uniformity KW - statistics KW - geostatistics KW - semivariance KW - kriging ER - TY - JOUR TI - Factors affecting seed germination of tropical signalgrass (Urochloa subquadripara) AU - Teuton, Travis C. AU - Brecke, Barry J. AU - Unruh, J. Bryan AU - MacDonald, Greg E. AU - Miller, Grady L. AU - Ducar, Joyce Tredaway T2 - Weed Science AB - Tropical signalgrass is one of the dominant weeds in the Florida turfgrass industry and is potentially troublesome for the southeastern turfgrass industry. Tropical signalgrass is especially problematic for St. Augustinegrass sod producers because of lack of control options. The objectives of our research were to determine the effect of light, pH, temperature, water potential, and planting depth on tropical signalgrass germination and emergence. Tropical signalgrass germination does not require light and is optimum at pH 5 to 6, temperature 25 C, and water potentials greater than − 0.4 MPa. Tropical signalgrass shoots emerged from depths of 0 to 7 cm, with maximum germination when placed on the soil surface. Tropical signalgrass seedlings emerged in the field during the second week of March in Ft. Lonesome, FL. Weekly mean soil and ambient air temperatures at the time of emergence were 20 C. Tropical signalgrass emergence was first observed at 118 and 73 growing degree-days (GDD) (13 C base temperature), with a peak emergence period at 222 and 156 GDD for 2001 and 2002, respectively. DA - 2004/5// PY - 2004/5// DO - 10.1614/ws-03-121r1 VL - 52 IS - 3 SP - 376-381 J2 - Weed Science LA - en OP - SN - 0043-1745 1550-2759 UR - http://dx.doi.org/10.1614/ws-03-121r1 DB - Crossref KW - seed germination KW - emergence KW - light KW - pH KW - temperature KW - depth of emergence KW - time of emergence ER - TY - JOUR TI - St. Augustinegrass Response to Plant Growth Retardants AU - McCarty, Lambert B. AU - Weinbrecht, Jan S. AU - Toler, Joe E. AU - Miller, Grady L. T2 - Crop Science AB - St. Augustinegrass [( Stenotaphrum secundatum (Walt.) Kuntz.] is the preferred warm‐season turfgrass for Florida's commercial and residential landscapes with an estimated 0.7 million hectare under growth and management. Limited published information is available on St. Augustinegrass response to plant growth retardants (PGRs). A 2‐yr study was implemented to monitor St. Augustinegrass turf quality, lateral stolon growth, percent cover, mowing frequency, cumulative turfgrass clippings, and seedhead suppression following PGR application. Treatments were applied on 23 June 1995 and 22 June 1996 as a single application (SIA) at label use rate (LUR) or as twin split applications (TSA) at half LUR each: the sequential application was only used when mowing interval equaled the untreated. The PGRs and rates were flurprimidol [α‐(1‐methylethyl)‐α‐[4‐(trifluoro‐methoxy)phenyl]‐5‐pyrimidine‐methanol] and paclobutrazol [(+/−)‐(R*,R*)‐β‐[(4‐chloro‐phenyl)methyl]‐α‐(1,1‐dimethylethyl)‐1 H ‐1,2,4‐triazole‐1‐ethanol] at 1.12 kg ha −1 for SIA and 0.56 kg ha −1 for TSA, trinexapac‐ethyl [4‐(cyclopropyl‐α‐hydroxymethylene)‐3,5‐dioxocyclohexane carboxylic acid ethylester] and mefluidide [ N ‐[2,4‐dimethyl‐5‐[[trifluoromethyl)sulfonyl]amino]phenyl]acetamide] at 0.28 kg ha −1 for SIA and 0.14 kg ha −1 for TSA, and imazapic [(±)‐2‐[4,5‐dihydrol‐4‐methyl‐4‐(1‐methylethyl)‐5‐oxo‐1 H ‐imidazol‐2‐yl]‐5‐methyl‐3‐pyridine‐carboxylic acid] at 0.028 kg ha −1 for SIA and 0.014 kg ha −1 for TSA. Responses were observed for a 12‐wk period following initial application, and turf quality was acceptable (>7) for all PGRs. Turf quality for imazapic was generally better than the untreated for Weeks 6 to 10. Greatest control of lateral stolon growth 10 wk after initial application was achieved with TSA of imazapic (68%) and mefluidide (61%). Percent cover 12 wk after initial application was lowest for SIA and TSA imazapic (66 and 53%, respectively). Greatest reduction in mowing frequency was provided by trinexapac‐ethyl (50%), while flurprimidol and mefluidide reduced mowing frequency by 26 and 20%, respectively. The only PGR that reduced cumulative turfgrass clippings (CTC) was trinexapac‐ethyl (63%). Greatest seedhead inhibition during peak production (about 35%) was provided by imazapic and mefluidide. The two most effective PGRs were trinexapac‐ethyl (reduced mowing frequency and CTC) and imazapic (controlled lateral stolon growth and seedhead production), while mefluidide demonstrated some potential. Combinations of these products could be examined in future studies. DA - 2004/// PY - 2004/// DO - 10.2135/cropsci2004.1323 VL - 44 IS - 4 SP - 1323 LA - en OP - SN - 1435-0653 UR - http://dx.doi.org/10.2135/cropsci2004.1323 DB - Crossref ER - TY - JOUR TI - Tropical Signalgrass (Urochloa subquadripara) Control with Preemergence- and Postemergence-Applied Herbicides AU - Teuton, Travis C. AU - Unruh, J. Bryan AU - Brecke, Barry J. AU - Macdonald, Greg E. AU - Miller, Grady L. AU - Ducar, Joyce Tredaway T2 - Weed Technology AB - Tropical signalgrass is one of the most serious weed problems in the St. Augustinegrass sod production in Florida, and its presence increases production costs and lowers turfgrass quality. The objectives of our research were to: (1) evaluate herbicides preemergence and postemergence for control of tropical signalgrass and (2) compare control of tropical signalgrass and other problem weeds (torpedograss, blanket crabgrass, and India crabgrass) with postemergence herbicides. In preemergence herbicide field trials, only benefin + oryzalin, imazapic, imazapic + 2,4-D, and oryzalin provided ≥75% tropical signalgrass control 8 wk after application (WAA). By 11 WAA, only benefin + oryzalin and imazapic + 2,4-D provided ≥75% tropical signalgrass control. In greenhouse experiments, eight herbicide treatments were applied postemergence to tropical signalgrass seedlings at the two-, four-, six-, and eight-leaf stages. Asulam and CGA 362622 provided ≥89% tropical signalgrass control at all application timings. Imazaquin controlled tropical signalgrass ≥98% when applied before the eight-leaf stage. However, in field trials with mature tropical signalgrass (>20 cm stolons), none of the 20 herbicide treatments applied postemergence provided acceptable control. DA - 2004/6// PY - 2004/6// DO - 10.1614/wt-03-155r1 VL - 18 IS - 02 SP - 419-425 J2 - Weed technol. LA - en OP - SN - 0890-037X 1550-2740 UR - http://dx.doi.org/10.1614/wt-03-155r1 DB - Crossref KW - BRASU KW - DIGLO KW - DIGSO KW - PANRE ER - TY - CONF TI - Identification of molecular markers associated with tomato spotted wilt virus in a genetic linkage map of Arachis kuhlmannii x A. diogoi AU - Milla, S.R. AU - Tallury, S.P. AU - Stalker, H.T. AU - Isleib, T.G. C2 - 2004/// C3 - Proceedings of the American Peanut Research and Education Society DA - 2004/// VL - 36 SP - 27 ER - TY - CONF TI - Molecular and genetic characterization of N. glutinosa chromosome segments in tobacco mosaic virus (TMV)-resistant tobacco accessions AU - Milla, S.R. AU - Lewis, R.S. T2 - 2004 CORESTA Conference C2 - 2004/// DA - 2004/// SP - 11 ER - TY - CONF TI - Utilización de marcadores AFLP para el estudio de diversidad genética del maní y especies relacionadas AU - Milla, S.R. AU - Isleib, T.G. AU - Stalker, H.T. C2 - 2004/// C3 - Libro de Resúmenes del III Encuentro Científico Internacional de Invierno DA - 2004/// SP - 16 ER - TY - SOUND TI - Chromosome regions associated with TSWV resistance in the peanut wild relative Arachis diogoi Hoehne AU - Milla, S.R. AU - Stalker, H.T. AU - Tallury, S.P. AU - Isleib, T.G. DA - 2004/10/31/ PY - 2004/10/31/ ER - TY - CONF TI - A program of selection for multiple disease resistance AU - Isleib, T.G. AU - Milla, S.R. AU - Copeland, S.C. AU - Graeber, J.B. C2 - 2004/// C3 - Proceedings of the American Peanut Research and Education Society DA - 2004/// VL - 36 SP - 34 ER - TY - CONF TI - Breeding for increased rye allelopathy AU - Reberg-Horton, S.C. AU - Creamer, N.G. AU - Murphy, J.P. C2 - 2004/// C3 - Proceedings of the Annual Meeting - Northeastern Weed Science Society DA - 2004/// VL - 58 SP - 157 ER - TY - NEWS TI - Organic no-till forages for Maine T2 - Maine Organic Milk Producers Newsletter PY - 2004/// ET - Fall SP - 4–6 ER - TY - JOUR TI - Effect of temperature on the germination of common waterhemp (Amaranthus tuberculatus), giant foxtail (Setaria faberi), and velvetleaf (Abutilon theophrasti) AU - Leon, R.G. AU - Knapp, A.D. AU - Owen, M.D.K. T2 - Weed Science AB - Common waterhemp, giant foxtail, and velvetleaf seed germination in response to temperature was studied with a two-way thermogradient plate. Seeds were maintained under dark and wet conditions at 4 C for 12 wk, and velvetleaf seeds were scarified before the experiments were conducted. The seeds were germinated at 25 different temperature treatments. Minimum and optimum temperatures for velvetleaf germination were approximately 8 and 24 C, respectively. Temperature alternation did not affect the germination of this species. The minimum germination temperature was 10 C for common waterhemp and 14 C for giant foxtail. The optimum germination of giant foxtail occurred at approximately 24 C, but common waterhemp optimum germination was variable depending on temperature alternation. Increased amplitude of the diurnal temperature alternation increased percent germination of these two species, and this was more evident at lower temperatures. In the case of common waterhemp, the temperature required to reach specific germination percentages was reduced by increasing the amplitude of the temperature alternation. DA - 2004/// PY - 2004/// DO - 10.1614/p2002-172 VL - 52 IS - 01 SP - 67-73 KW - germination KW - dormancy KW - seed KW - weed KW - temperature alternation KW - temperature fluctuation ER - TY - JOUR TI - Artificial and natural seed banks differ in seedling emergence patterns AU - Leon, R.G. AU - Owen, M.K.D. T2 - Weed Science AB - Artificial weed seed banks are practical for studying seed bank depletion and weed seedling emergence because the number, depth, and species composition of seed banks can be managed. However, no studies have determined whether artificial seed banks are representative of natural seed banks. We compared the emergence of velvetleaf, giant foxtail, and common waterhemp in a natural seed bank, an artificial seed bank with stratified seeds, and an artificial seed bank with nonstratified seeds. Velvetleaf seedling emergence was higher in the nonstratified seed bank in 2001, but no differences were observed in 2002. The number of viable velvetleaf seeds at the end of the experiment was lower in the natural seed bank than in the artificial seed banks in 2002. Velvetleaf emergence occurred earlier in the natural seed bank than in the artificial seed banks. Giant foxtail emergence was higher in the artificial seed banks (58 to 82%) than in the natural seed bank (5 to 23%). Common waterhemp emergence ranged from 7 to 65% in the artificial seed banks and from 1 to 5% in the natural seed bank. In general, the distribution of emergence with time differed in the natural seed bank compared with the artificial seed banks. These differences were attributed to differences in soil temperature and soil bulk density between the natural and artificial seed banks. Artificial seed banks showed lower soil bulk density and greater temperature fluctuation than the natural seed bank. However, there was no consistent relationship between growing degree days and emergence timing in the three treatments for any of the species studied. DA - 2004/// PY - 2004/// DO - 10.1614/ws-03-048r2 VL - 52 IS - 04 SP - 531–537 ER - TY - JOUR TI - Role of molecular oxygen in the dissolution of siderite and rhodochrosite AU - Duckworth, O.W. AU - Martin, S.T. T2 - Geochimica et Cosmochimica Acta DA - 2004/// PY - 2004/// DO - 10.1016/S0016-7037(00)00464-2 VL - 68 IS - 3 SP - 607-621 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0742322779&partnerID=MN8TOARS ER - TY - JOUR TI - Linear free energy relationships between dissolution rates and molecular modeling energies of rhombohedral carbonates AU - Duckworth, O.W. AU - Cygan, R.T. AU - Martin, S.T. T2 - Langmuir AB - Bulk and surface energies are calculated for endmembers of the isostructural rhombohedral carbonate mineral family, including Ca, Cd, Co, Fe, Mg, Mn, Ni, and Zn compositions. The calculations for the bulk agree with the densities, bond distances, bond angles, and lattice enthalpies reported in the literature. The calculated energies also correlate with measured dissolution rates: the lattice energies show a log-linear relationship to the macroscopic dissolution rates at circumneutral pH. Moreover, the energies of ion pairs translated along surface steps are calculated and found to predict experimentally observed microscopic step retreat velocities. Finally, pit formation excess energies decrease with increasing pit size, which is consistent with the nonlinear dissolution kinetics hypothesized for the initial stages of pit formation. DA - 2004/// PY - 2004/// DO - 10.1021/la035348x VL - 20 IS - 7 SP - 2938-2946 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-1842741155&partnerID=MN8TOARS ER - TY - JOUR TI - Effects of the biologically produced polymer alginic acid on macroscopic and microscopic calcite dissolution rates T2 - Environmental Science and Technology AB - Dissolution of carbonate minerals has significant environmental effects. Microorganisms affect carbonate dissolution rates by producing extracellular metabolites, including complex polysaccharides such as alginic acid. Using a combined atomic force microscopy (AFM)/flow-through reactor apparatus, we investigated the effects of alginic acid on calcite dissolution. Macroscopic dissolution rates, derived from the aqueous metal ion concentrations, are 10-5.5 mol m-2 s-1 for 5 < pH < 12 in the absence of alginic acid compared to 10-4.8 mol m-2 s-1 in its presence. The AFM images demonstrate that alginic acid preferentially attacks the obtuse steps of dissolution pits on the calcite surface. In pure water, the obtuse and acute steps retreat at similar rates, and the pits are nearly isotropic except under highly acidic conditions. In alginic acid, the acute step retreat rate is nearly unchanged in comparison to water, whereas the obtuse step retreat rate increases with decreasing pH values. As a result, the pits remain rhombohedral but propagate faster in the obtuse direction. To explain these observations, we propose that alginic acid preferentially forms dissolution active surface complexes with calcium atoms on the obtuse step, which results in anisotropic ligand-promoted dissolution. DA - 2004/// PY - 2004/// DO - 10.1021/es035299a VL - 38 IS - 11 SP - 3040-3046 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-2542420918&partnerID=MN8TOARS ER - TY - JOUR TI - Dissolution rates and pit morphologies of rhombohedral carbonate minerals AU - Duckworth, O.W. AU - Martin, S.T. T2 - American Mineralogist DA - 2004/// PY - 2004/// VL - 89 IS - 4 SP - 554-563 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-1942499445&partnerID=MN8TOARS ER - TY - CONF TI - Temporal pattern and spatial complexity of shallow groundwater nitrate in a coastal plain agricultural field AU - Hong, N. AU - White, J.G. AU - Gumpertz, M.L. AU - Weisz, R. A2 - Mulla, D.J. A2 - Swenson, J.A. C2 - 2004/7/25/ C3 - Proc. Int. Conf. Precision Agric. and other Precision Natural Resource Management, 7th, Bloomington, MN DA - 2004/7/25/ PB - ASA/SSSA/CSSA ER - TY - CONF TI - Remote sensing for precision N management in a corn-wheat-soybean rotation AU - Crozier, C.R. AU - White, J.G. AU - Weisz, R. AU - Heiniger, R. AU - Crouse, D.A. AU - Garoma, M. AU - Farrer, D. AU - Sripada, R.P. AU - Hong, N. AU - Williams, J. A2 - Mulla, D.J. A2 - Swenson, J.A. C2 - 2004/// C3 - Proc. Int. Conf. Precision Agric. and other Precision Natural Resource Management, 7th, Bloomington, MN DA - 2004/// PB - ASA/SSSA/CSSA ER - TY - CONF TI - Remote sensing based early and late in-season N management decisions in corn AU - Sripada, R.P. AU - Heiniger, R.W. AU - White, J.G. AU - Crozier, C.R. A2 - Mulla, D.J. A2 - Swenson, J.A. C2 - 2004/7/25/ C3 - Proc. Int. Conf. Precision Agric. and other Precision Natural Resource Management, 7th, Bloomington, MN DA - 2004/7/25/ PB - ASA/SSSA/CSSA ER - TY - CONF TI - Covariance model selection in spatial analysis of yield-monitor data in randomized complete blocks AU - Hong, N. AU - White, J.G. AU - Gumpertz, M.L. AU - Weisz, R. A2 - Mulla, D.J. A2 - Swenson, J.A. C2 - 2004/7// C3 - Proc. Int. Conf. Precision Agric. and other Precision Natural Resource Management, 7th, Bloomington, MN DA - 2004/7// PB - ASA/SSSA/CSSA ER - TY - BOOK TI - Environmental impact of fertilizer on soil and water AU - William L. Hall, editor AU - Wayne P. Robarge, editor AB - Ion chromatography (IC) has been approved for the analysis of inorganic anions in environmental waters since the mid-1980s, as described in EPA Method 300.0. Recent advances in instrumentation, columns and detection technology have expanded the scope of IC methods for analytes other than common anions, e.g., disinfection byproduct anions, chromate and perchlorate. In this paper, we review recent developments for the determination of low μg/L levels of anions and perchlorate in environmental samples by IC. The application of EPA Method 314.0 for the analysis of perchlorate in higher ionic strength samples, such as fertilizers, will be also be considered, in addition to the use of electrospray MS detection as a confirmatory technique for anion identification DA - 2004/// PY - 2004/// DO - 10.1021/bk-2004-0872 PB - Washington, DC: American Chemical Society ;|a[New York?]: distributed by Oxford University Press ER - TY - CONF TI - Microarray analysis of gene expression in OP pine families in field plantings AU - Whetten, R. W. AU - Li, Z. AU - McKeand, S. E. A2 - Li, B. A2 - McKeand, S. C2 - 2004/// C3 - Forest Genetics and Tree Breeding in the Age of Genomics: Progress and Future, IUFRO Joint Conference of Division 2, Conference Proceedings DA - 2004/// SP - 257-269 ER - TY - JOUR TI - Visual selection for yield in cotton breeding programs AU - Bowman, D. T. AU - Bourland, F. M. AU - Myers, G. O. AU - Wallace, T. P. AU - Caldwell, D. T2 - Journal of Cotton Science (Online) DA - 2004/// PY - 2004/// VL - 8 IS - 2 SP - 62 ER - TY - JOUR TI - Italian ryegrass (Lolium multiflorum) control in imidazolinone-resistant wheat AU - Clemmer, KC AU - York, AC AU - Brownie, C T2 - WEED TECHNOLOGY AB - Imazamox ammonium salt at 53 g ae/ha applied postemergence in the fall to imidazolinone-resistant wheat controlled Italian ryegrass 98 to 100% 10 wk after treatment (WAT). Control 22 WAT was 88 to 98% at two locations and 55% at a third location. Imazamox was more effective applied in fall to three- to four-leaf Italian ryegrass than when applied in spring to one- to three-tiller Italian ryegrass. Split applications, with 27 g/ha applied in fall and spring, were no more effective than 53 g/ha applied in fall. Pendimethalin preemergence in combination with fall-applied imazamox increased control 22 WAT 10 to 33 percentage points at two of three locations. Imazethapyr ammonium salt plus imazapyr isopropylamine salt applied at 47 plus 16 g ae/ha and imazamox at 44 or 53 g/ha were similarly effective, whereas imazethapyr at 70 g/ha was ineffective. Control by imazapic ammonium salt at 70 g ae/ha was equal to or greater than control by imazamox at 44 or 53 g/ha. Imazamox, imazethapyr plus imazapyr, and imazapic controlled diclofop-resistant and -susceptible Italian ryegrass. Thifensulfuron plus tribenuron mixed with imazamox increased Italian ryegrass control in field and greenhouse experiments, whereas dicamba reduced control compared with imazamox applied alone. Control by imazamox plus 2,4-D was similar to or greater than control by imazamox alone. DA - 2004/// PY - 2004/// DO - 10.1614/WT-03-017R VL - 18 IS - 3 SP - 481-489 SN - 1550-2740 KW - herbicide interactions KW - herbicide-resistant weeds KW - weed management ER - TY - JOUR TI - Drug use survey and evaluation of quality assurance training for meat goat producers AU - Anderson, K. L. AU - Brownie, C. AU - Luginbuhl, J. M. AU - Mobley, M. T2 - International Journal of Applied Research in Veterinary Medicine DA - 2004/// PY - 2004/// VL - 2 IS - 4 SP - 261 ER - TY - JOUR TI - Cynodon spp. management programs for the upper transition zone in the Southeastern United States AU - Bruneau, AH AU - Peacock, CH AU - Cooper, RJ AU - Erickson, EJ T2 - PROCEEDINGS OF THE 1ST INTERNATIONAL CONFERENCE ON TURFGRASS MANAGEMENT AND SCIENCE SPORTS FIELDS DA - 2004/// PY - 2004/// DO - 10.17660/actahortic.2004.661.75 IS - 661 SP - 551-557 SN - 0567-7572 KW - athletic field KW - bermudagrass KW - golf course KW - turfgrass ER - TY - JOUR TI - Changes in physical properties of coir dust substrates during crop production AU - Nelson, PV AU - Oh, YM AU - Cassel, DK T2 - PROCEEDINGS OF THE INTERNATIONAL SYMPOSIUM ON GROWING MEDIA & HYDROPONICS DA - 2004/// PY - 2004/// DO - 10.17660/actahortic.2004.644.35 IS - 644 SP - 261-268 SN - 2406-6168 KW - container capacity KW - air space KW - available water KW - bulk density KW - shrinkage KW - impatiens wallerana L. ER - TY - JOUR TI - Response of strip-tilled cotton to preplant applications of dicamba and 2,4-D AU - York, A. C. AU - Culpepper, A. S. AU - Stewart, A. M. T2 - Journal of Cotton Science (Online) DA - 2004/// PY - 2004/// VL - 8 IS - 3 SP - 213 ER - TY - JOUR TI - Performance of glyphosate-tolerant cotton cultivars in official cultivar trials AU - York, A. C. AU - Culpepper, A. S. AU - Bowman, D. T. AU - May, O. L. T2 - Journal of Cotton Science (Online) DA - 2004/// PY - 2004/// VL - 8 IS - 4 SP - 261 ER - TY - JOUR TI - Hybridization and backcrossing between transgenic oilseed rape and two related weed species under field conditions AU - Halfhill, M. D. AU - Zhu Bin, Warwick S. I. AU - Raymer, P. L. AU - Millwood, R. J. AU - Weissinger, A. K. AU - Stewart, C. N. T2 - Environmental Biosafety Research AB - Determining the frequency of crop-wild transgene flow under field conditions is a necessity for the development of regulatory strategies to manage transgenic hybrids. Gene flow of green fluorescent protein (GFP) and Bacillus thuringiensis (Bt) transgenes was quantified in three field experiments using eleven independent transformed Brassica napus L. lines and the wild relatives, B. rapa L. and Raphanus raphanistrum L. Under a high crop to wild relative ratio (600:1), hybridization frequency with B. rapa differed among the individual transformed B. napus lines (ranging from ca. 4% to 22%), however, this difference could be caused by the insertion events or other factors, e.g., differences in the hybridization frequencies among the B. rapa plants. The average hybridization frequency over all transformed lines was close to 10%. No hybridization with R. raphanistrum was detected. Under a lower crop to wild relative ratio (180:1), hybridization frequency with B. rapa was consistent among the transformed B. napus lines at ca. 2%. Interspecific hybridization was higher when B. rapa occurred within the B. napus plot (ca. 37.2%) compared with plot margins (ca. 5.2%). No significant differences were detected among marginal plants grown at 1, 2, and 3 m from the field plot. Transgene backcrossing frequency between B. rapa and transgenic hybrids was determined in two field experiments in which the wild relative to transgenic hybrid ratio was 5-15 plants of B. rapa to 1 transgenic hybrid. As expected, ca. 50% of the seeds produced were transgenic backcrosses when the transgenic hybrid plants served as the maternal parent. When B. rapa plants served as the maternal parent, transgene backcrossing frequencies were 0.088% and 0.060%. Results show that transgene flow from many independent transformed lines of B. napus to B. rapa can occur under a range of field conditions, and that transgenic hybrids have a high potential to produce transgenic seeds in backcrosses. DA - 2004/// PY - 2004/// DO - 10.1051/ebr:2004007 VL - 3 IS - 2 SP - 73 ER - TY - JOUR TI - Effects of salinity on six bermudagrass turf cultivars AU - Peacock, CH AU - Lee, DJ AU - Reynolds, WC AU - Gregg, JP AU - Cooper, RJ AU - Bruneau, AH T2 - PROCEEDINGS OF THE 1ST INTERNATIONAL CONFERENCE ON TURFGRASS MANAGEMENT AND SCIENCE SPORTS FIELDS DA - 2004/// PY - 2004/// DO - 10.17660/actahortic.2004.661.24 IS - 661 SP - 193-197 SN - 0567-7572 KW - bermudagrass KW - Cynodon spp. KW - salinity tolerance ER - TY - JOUR TI - Dose and concentration responses of common nursery weeds to Gallery, Surflan and Treflan AU - Judge, C. A. AU - Neal, J. C. AU - Weber, J. B. T2 - Journal of Environmental Horticulture DA - 2004/// PY - 2004/// VL - 22 IS - 2 SP - 106 ER - TY - JOUR TI - Roles of microtubules and cellulose microfibril assembly in the localization of secondary-cell-wall deposition in developing tracheary elements AU - Roberts, AW AU - Frost, AO AU - Roberts, EM AU - Haigler, CH T2 - PROTOPLASMA DA - 2004/12// PY - 2004/12// DO - 10.1007/s00709-004-0064-4 VL - 224 IS - 3-4 SP - 217-229 SN - 0033-183X KW - amiprophosmethyl KW - cellulose microfibril assembly KW - Congo Red KW - cortical microtubule KW - Evans Blue KW - xylogenic suspension culture ER - TY - BOOK TI - A systematic evaluation of polyacrylamide for sediment and turbidity control AU - McLaughlin, R. A. DA - 2004/// PY - 2004/// PB - Raleigh, NC: Water Resources Research Institute of the University of North Carolina ER - TY - JOUR TI - Nitrification options for pig wastewater treatment AU - Szogi, A. A. AU - Vanotti, M. B. AU - Rice, J. M. AU - Humenik, F. J. AU - Hunt, P. G. T2 - New Zealand Journal of Agricultural Research AB - Abstract Nitrification is a necessary and often limiting process in animal waste treatment for removal of nitrogen as N2 through biological nitrification/denitrification systems. We evaluated three technologies for enhancing nitrification of pig lagoon wastewater prior to denitrification: overland flow, trickling filter, and a bioreactor using nitrifying pellets. The overland flow system consisted of a 4 × 20‐m plot with 2% slope with a subsurface impermeable barrier receiving a total N loading rate of 64–99 kg N ha−1 day−1. Total N removal efficiency ranged from 36 to 42%, and 7% of the total N application was recovered in the effluent as nitrate. The trickling filter consisted of a 1‐m3 tank filled with marl gravel media which supported a nitrifying biofilm. Lagoon wastewater was applied as a fine spray on the surface at hydraulic loading rates of 684 litres m−3 day−1 and total N loading rates of 249 g m−3 day−1. The media filter treatment transformed up to 57% of the inflow total N into nitrate when wastewater was supplemented with lime. The nitrifying pellets technology used acclimated nitrifying cells immobilised in 3–5 mm polymer pellets. Pig wastewater was treated in an aerated fluidised reactor unit with a 15% (w/v) pellet concentration. Nitrification efficiencies of more than 90% were obtained in continuous flow treatment using total N loading rates of 438 g N m−3 day−1 and hydraulic residence time of 12 h. Two conclusions are suggested from this research: (1) that substantial nitrification of pig lagoon wastewater can be attained particularly using aerobic treatments with enriched nitrifying populations, and (2) that large mass removal of N from pig wastewater may be possible by sequencing nitrification and denitrification unit processes. DA - 2004/// PY - 2004/// DO - 10.1080/00288233.2004.9513612 VL - 47 IS - 4 SP - 439-448 ER - TY - JOUR TI - Construction of platinum-tipped redox probes for determining soil redox potential AU - Wafer, CC AU - Richards, JB AU - Osmond, DL T2 - JOURNAL OF ENVIRONMENTAL QUALITY AB - ABSTRACT Redox probes are typically constructed by soldering Pt wire to a metal wire or rod, such as copper or brass. The junction between the Pt and wire or rod is often sealed with an epoxy resin and hardener or with heat‐shrink tubing. Microcracks (small cracks invisible to the unaided eye) can form in the hardened resin and result in incorrect readings. The hardened resin is not easily removed, making repairs difficult. Heat‐shrink tubing is thin, lacks rigidity, and can be damaged in the soil. The method described in this paper used a thick‐walled, adhesive‐lined terminal insulator to seal the junction. The terminal insulators were easily applied and removed, which made faulty probes easy to repair. Two‐hundred forty probes were made with this method and eight were made with a marine epoxy resin. The probes were tested with a redox buffer solution (Light Solution) and were usable if they read +476 ± 10 mV. The probes were installed 0.76 and 1.5 m deep in the soil. The ability of the probes to provide reliable redox readings was examined by testing selected probes after 10 mo of use and testing all of the probes after completion of the study (19 mo). Ten of the twelve probes tested after 10 mo worked satisfactorily, while the other two clearly malfunctioned before testing. After the study was completed, 236 of the 240 of the probes worked satisfactorily. These results indicate that the construction method presented produces reliable, long‐lasting probes. DA - 2004/// PY - 2004/// DO - 10.2134/jeq2004.2375 VL - 33 IS - 6 SP - 2375-2379 SN - 1537-2537 ER - TY - JOUR TI - Physiological behavior of root-absorbed flumioxazin in peanut, ivyleaf morningglory (Ipomoea hederacea), and sicklepod (Senna obtusifolia) AU - Price, AJ AU - Wilcut, JW AU - Cranmer, , JR T2 - WEED SCIENCE AB - Previous research has shown that flumioxazin has the potential to cause peanut injury. In response to this concern, laboratory and greenhouse experiments were conducted to investigate the influence of temperature on germination of flumioxazin-treated peanut seed and the effect of interval between flumioxazin application and irrigation on peanut emergence and injury. Laboratory experiments using 14C-flumioxazin were also conducted to investigate differential tolerance exhibited by peanut, ivyleaf morningglory, and sicklepod to flumioxazin. Flumioxazin treatments containing either water-dispersible granular or wettable powder formulation at 1.4 μmol L−1 did not influence germination compared with nontreated peanut across all temperature regimes (15 to 40 C). Peanut treated with either formulations of flumioxazin preemergence and receiving irrigation at emergence and 2 and 4 d after emergence were injured between 40 and 60%. Peanut treated at 8 and 12 d after emergence were injured between 25 and 15%, respectively. Total 14C absorbed by ivyleaf mornigglory was 57% of applied whereas sicklepod absorbed 46%, 72 h after treatment (HAT). Peanut absorbed > 74% of applied 14C 72 HAT. The majority of absorbed 14C remained in roots of sicklepod, ivyleaf morningglory, and peanut at all harvest times. Ivyleaf morningglory contained 41% of the parent herbicide 72 HAT whereas sicklepod and peanut contained only 24 and 11% parent compound, respectively. Regression slopes indicated slower flumioxazin metabolism by ivyleaf morningglory (a susceptible species) compared with sicklepod and peanut (tolerant species). DA - 2004/// PY - 2004/// DO - 10.1614/WS-04-017R VL - 52 IS - 5 SP - 718-724 SN - 0043-1745 KW - absorption KW - translocation KW - metabolism ER - TY - JOUR TI - Moving beyond the winter hardiness plateau in US oat germplasm AU - Livingston, DP AU - Elwinger, GF AU - Murphy, JP T2 - CROP SCIENCE AB - Progress has been slow in the development of winter-hardy oat (Avena sativa L.) cultivars. No cultivar released in the last 40 yr has better freezing tolerance than the cultivar Norline, which was released in 1960. However, in an analysis of 65 yr of field testing, Norline was not more winter hardy than ‘Wintok’, which was released in 1940. An analysis of individual location–year combinations of Wintok and Norline suggested that progeny from a cross of these two cultivars might contain germplasm that was transgressive for freezing tolerance. The objective of this research was to use mass selection in controlled environment freeze tests on successive segregating generations of the cross between Wintok and Norline to identify inbred progenies with significantly greater winter hardiness than either parent. Following three generations of seed increase and three generations of selection for freezing tolerance in controlled freeze tests, several F7 genotypes were identified with greater freezing tolerance than both parents. In the F9 generation, two of the lines exhibited a higher level of freezing tolerance than either parent, and both were slightly more freezing tolerant than the moderately winter-hardy barley, Hordeum vulgare ‘Trebi’. DA - 2004/// PY - 2004/// DO - 10.2135/cropsci2004.1966 VL - 44 IS - 6 SP - 1966-1969 SN - 0011-183X ER - TY - JOUR TI - Glyphosate negatively affects pollen viability but not pollination and seed set in glyphosate-resistant corn AU - Thomas, WE AU - Pline-Srnic, WA AU - Thomas, JF AU - Edmisten, KL AU - Wells, R AU - Wilcut, JW T2 - WEED SCIENCE AB - Experiments were conducted in the North Carolina State University Phytotron greenhouse and field locations in Clayton, Rocky Mount, and Lewiston-Woodville, NC, in 2002 to determine the effect of glyphosate on pollen viability and seed set in glyphosate-resistant (GR) corn. Varieties representing both currently commercial GR corn events, GA21 and NK603, were used in phytotron and field studies. All glyphosate treatments were applied at 1.12 kg ai ha−1 at various growth stages. Regardless of hybrid, pollen viability was reduced in phytotron and field studies with glyphosate treatments applied at the V6 stage or later. Scanning electron microscopy of pollen from affected treatments showed distinct morphological alterations correlating with reduced pollen viability as determined by Alexander stain. Transmission electron microscopy showed pollen anatomy alterations including large vacuoles and lower starch accumulation with these same glyphosate treatments. Although pollen viability and pollen production were reduced in glyphosate treatments after V6, no effect on kernel set or yield was found among any of the reciprocal crosses in the phytotron or field studies. There were also no yield differences among any of the hand self-pollinated (nontreated male × nontreated female, etc.) crosses. Using enzyme-linked immunosorbent assay to examine CP4-5-enolpyruvlshikimate-3-phosphate synthase expression in DKC 64-10RR (NK603) at anthesis, we found the highest expression in pollen with progressively less in brace roots, ear leaf, anthers, roots, ovaries, silks, stem, flag leaf, and husk. DA - 2004/// PY - 2004/// DO - 10.1614/WS-03-134R VL - 52 IS - 5 SP - 725-734 SN - 1550-2759 KW - Alexander stain KW - fluorochromatic reaction KW - pollen viability KW - GA21 KW - NK603 KW - mEPSPS KW - CP4-EPSPS KW - ELISA ER - TY - JOUR TI - Factors affecting the realized niche of common sunflower (Helianthus annuus) in ridge-tillage corn AU - Burton, MG AU - Mortensen, DA AU - Marx, DB AU - Lindquist, JL T2 - WEED SCIENCE AB - Because soil characteristics and weed densities vary within agricultural landscapes, determining which subfield areas are most favorable to weed species may aid in their management. Field and greenhouse studies were conducted to determine whether subfield environments characterized by higher soil organic carbon (SOC), or ridge vs. furrow microsites, affect common sunflower seed germination after winter burial, seedling emergence, or the control afforded by a preemergence herbicide in a ridge-tillage corn production system. Among seeds buried in situ during winter months and germinated in the laboratory, no differences in common sunflower seed germination or mortality were detected between high-SOC (1.8% mean) and low-SOC (1.1% mean) locations. However, seeds buried at 5-cm depth had about 40% laboratory germination compared with about 10% for seeds stratified on the soil surface or under crop residues. In field emergence and survival experiments, the SOC main-plot effect indicated 25% greater seedling survival in high- than in low-SOC locations. In the absence of herbicide, both emergence and survival were ≥ 35% greater in the ridge than in the furrow microsite, and seedling survival was 48% greater in high- vs. low-SOC furrow environments. However, common sunflower seedling survival was similar between herbicide-treated high- and low-SOC ridges. Greenhouse studies indicated a 13 to 24% increase in common sunflower seedling biomass per 1% increase in SOC under three atrazine doses. Altered or additional weed management tactics should be considered for common sunflower in high-SOC environments to offset the greater potential for seedling survival and growth. DA - 2004/// PY - 2004/// DO - 10.1614/P2001-101 VL - 52 IS - 5 SP - 779-787 SN - 0043-1745 KW - atrazine KW - soil heterogeneity KW - soil organic matter KW - weed population dynamics ER - TY - JOUR TI - Efficacy of selected nematicides for management of Hoplolaimus columbus in cotton. AU - Koenning, S. R. AU - Morrison, D. E. AU - Edmisten, K. L. AU - Taylor, R. N. T2 - Nematropica DA - 2004/// PY - 2004/// VL - 34 IS - 2 SP - 211-218 ER - TY - JOUR TI - Dissolution of phosphate in a phosphorus-enriched ultisol as affected by microbial reduction AU - Hutchison, KJ AU - Hesterberg, D T2 - JOURNAL OF ENVIRONMENTAL QUALITY AB - Phosphorus dissolution often increases as soils become more reduced, but the mechanisms are not fully understood. The objectives of this research were to determine rates and mechanisms of P dissolution during microbial reduction of a surface soil from the North Carolina Coastal Plain. Duplicate suspensions of silt + clay fractions from a Cape Fear sandy clay loam (fine, mixed, semiactive, thermic Typic Umbraquult) were reduced in a continuously stirred redox reactor for 40 d. We studied the effects of three treatments on P dissolution: (i) 2 g dextrose kg(-1) solids added as a microbial carbon source at time 0 d; (ii) 2 g dextrose kg(-1) solids split into three additions at 0, 12, and 26 d; and (iii) no added dextrose. After 40 d of reduction, concentrations of dissolved reactive phosphorus (DRP) were similar for all treatments and increased up to sevenfold from 1.5 to 10 mg L(-1). The initial rate of reduction and dissolution of DRP was significantly greater for the 0-d treatment. A linear relationship (R(2) = 0.79) was found between DRP and dissolved organic carbon (DOC). Dissolved Fe and Al and pH increased, suggesting the formation of aqueous Fe- and Al-organic matter complexes. Separate batch experiments were performed to study the effects of increasing pH and citrate additions on PO(4) dissolution under aerobic conditions. Increasing additions of citrate increased concentrations of DRP, Fe, and Al, while increasing pH had no effect. Results indicated that increased dissolved organic matter (DOM) during soil reduction contributed to the increase in DRP, perhaps by competitive adsorption or formation of aqueous ternary DOM-Fe-PO(4) or DOM-Al-PO(4) complexes. DA - 2004/// PY - 2004/// DO - 10.2134/jeq2004.1793 VL - 33 IS - 5 SP - 1793-1802 SN - 1537-2537 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-4544353600&partnerID=MN8TOARS ER - TY - JOUR TI - DRAINWAT-based methods for estimating nitrogen transport in poorly drained watersheds AU - Amatya, D. M. AU - Chescheir, G. M. AU - Fernandez, G. P. AU - Skaggs, R. W. AU - Gilliam, J. W. T2 - Transactions of the ASAE AB - Methods are needed to quantify effects of land use and management practices on nutrient and sediment loads atthe watershed scale. Two methods were used to apply a DRAINMOD-based watershed-scale model (DRAINWAT) to estimatetotal nitrogen (N) transport from a poorly drained, forested watershed. In both methods, in-stream retention or losses of Nwere calculated with a lumped-parameter model, which assumes that N concentration decreases exponentially with residence(or travel) time in the canals. In the first method, daily field outflows predicted by DRAINWAT were multiplied by averageN concentrations to calculate daily loads at the field edge. Travel time from the field edge to the watershed outlet was computedfor each field for each day based on daily velocities predicted by DRAINWAT for each section of the canal-stream network.The second lumped-parameter method was similar but used predicted annual outflow to obtain annual load at the fieldedge. The load was transported to the watershed outlet, and the in-stream N loss was determined by using a constant averagevelocity (obtained by long-term DRAINWAT simulations), independent of season, for the entire canal-stream network. Themethods were applied on a 2,950 ha coastal forested watershed near Plymouth, North Carolina, to evaluate daily, monthly,and annual export of nitrogen for a five-year (1996-2000) period. Except for some late spring and hurricane events, predicteddaily flows were in good agreement with measured results for all five years (Nash-Sutcliffe coefficient, E = 0.71 to 0.85).Estimates of monthly total N load were in much better agreement (E = 0.76) with measured data than were the daily estimates(E = 0.19). Annual nitrogen load was predicted within 17% of the measured value, on average, and there was no difference(. = 0.05) between measured and estimated monthly and annual loads. The estimates of annual N loads using travel time witha daily velocity yielded better results than with the constant average velocity. The estimated delivery ratio (load at theoutlet/load at the field edge) for total N was shown to vary widely among individual fields depending on their location in thewatershed and distance from the outlet. Both of the methods investigated can potentially be used with GIS in predictingimpacts of land management practices on total N loads from poorly drained watersheds. DA - 2004/// PY - 2004/// DO - 10.13031/2013.16100 VL - 47 IS - 3 SP - 677-687 ER - TY - JOUR TI - Absorption, translocation and metabolism of halosulfuron and trifloxysulfuron in green kyllinga (Kyllinga brevifolia) and false-green kyllinga (K-gracillima) AU - McElroy, JS AU - Yelverton, FH AU - Burke, IC AU - Wilcut, JW T2 - WEED SCIENCE AB - Trifloxysulfuron controls green and false-green kyllinga more effectively than halosulfuron. Studies were conducted to evaluate the absorption, translocation, and metabolism of 14C-halosulfuron and 14C-trifloxysulfuron when foliar applied to green and false-green kyllinga. No differences were observed between the two kyllinga spp. with regard to absorption, translocation, or metabolism of either herbicide. The majority of 14C-halosulfuron and 14C-trifloxysulfuron was absorbed by 4 h, with an accumulation of 63 and 47% radioactivity, respectively. Accumulation of both herbicides occurred in the treated leaf and the primary shoot from whence the treated leaf was removed, with minor accumulation occurring in the roots and newly formed rhizomes. Of the total amount of 14C-halosulfuron absorbed into the plant, 77% remained in the form of the parent compound compared with 61% of 14C-trifloxysulfuron. The parent compound was distributed mainly in the treated leaf and primary shoot, whereas polar metabolites were concentrated in the roots and rhizomes. Nonpolar metabolites of 14C-trifloxysulfuron accumulated in the treated leaf and primary shoot. These data indicate that absorption, translocation, or metabolism could not explain the variation in green and false-green kyllinga control between halosulfuron and trifloxysulfuron. DA - 2004/// PY - 2004/// DO - 10.1614/WS-03-133R VL - 52 IS - 5 SP - 704-710 SN - 0043-1745 KW - acetolactate synthase KW - thin-layer chromatography KW - sulfonylurea ER - TY - JOUR TI - Weed management in glyphosate-resistant corn with glyphosate, halosulfuron, and mesotrione AU - Thomas, WE AU - Burke, IC AU - Wilcut, JW T2 - WEED TECHNOLOGY AB - Four field studies were conducted at the Peanut Belt Research Station near Lewiston Woodville, NC, in 2000, 2001, and 2002 to evaluate crop tolerance, weed control, grain yield, and net returns in glyphosate-resistant corn with various herbicide systems. Preemergence (PRE) treatment options included no herbicide, atrazine at 1.12 kg ai/ha, or atrazine plus metolachlor at 1.68 kg ai/ha. Postemergence (POST) treatment options included glyphosate at 1.12 kg ai/ha as either the isopropylamine salt or the diammonium salt, either alone or in mixtures with mesotrione at 105 g ai/ha plus crop oil concentrate at 1% (v/v) or halosulfuron at 53 g ai/ha plus 0.25% (v/v) nonionic surfactant. All response variables were independent of glyphosate formulation. Addition of metolachlor to atrazine PRE improved large crabgrass and goosegrass control but did not always improve Texas panicum control. POST control of these annual grasses was similar with glyphosate alone or in mixture with halosulfuron or mesotrione. Glyphosate POST controlled common lambsquarters and common ragweed 89 and 93%, respectively. Glyphosate plus halosulfuron POST provided more effective yellow nutsedge control than glyphosate POST. Atrazine PRE or atrazine plus metolachlor PRE followed by any glyphosate POST treatment controlled Ipomoea spp. at least 93%. Glyphosate plus mesotrione in total POST systems always provided greater control of Ipomoea spp. than glyphosate alone. The highest yielding treatments always included glyphosate POST, either with or without a PRE herbicide treatment. Similarly, systems that included any glyphosate POST treatment had the highest net returns. DA - 2004/// PY - 2004/// DO - 10.1614/WT-03-221R VL - 18 IS - 3 SP - 826-834 SN - 1550-2740 KW - diammonium salt KW - isopropylamine salt KW - net returns ER - TY - JOUR TI - Transgenic cotton with improved resistance to glyphosate herbicide AU - May, O. L. AU - Culpepper, A. S. AU - Cerny, R. E. AU - Coots, C. B. AU - Corkern, C. B. AU - Cothren, J. T. AU - Croon, K. A. AU - Ferreira, K. L. AU - Hart, J. L. AU - Hayes, R. M. AU - Huber, S. A. AU - Martens, A. B. AU - McCloskey, W. B. AU - Oppenhuizen, M. E. AU - Patterson, M. G. T2 - Crop Science AB - Glyphosate [N-(phosphonomethyl)glycine] herbicide can be topically applied twice at rates as high as 0.84 kg a.e. (acid-equivalent) ha−1 to glyphosate-resistant cotton (Gossypium hirsutum L.) cultivars until the fourth true leaf stage, with the requirement of at least 10 d and two nodes of growth between applications. But, such cultivars are not reproductively resistant to glyphosate applied topically or imprecisely directed after the four-leaf stage because glyphosate can curtail pollen development and ovule fertilization, which potentially reduces yield. Extending glyphosate resistance past the four-leaf stage would provide growers with additional weed management options. Our objective was to test under field conditions glyphosate resistance of cotton germplasm transformed with gene constructs previously shown to impart extended glyphosate resistance in the greenhouse. Four or six transgenic cotton lines containing one of several constructs conferring extended glyphosate resistance, plus the current glyphosate-resistant control (‘Coker 312’-1445), were tested at nine U.S. locations in 2001. Within locations, treatment designs consisted of cross-classified arrangements of transgenic lines and glyphosate rates [0, 1.68, and 2.52 kg a.e. ha−1]. Treated plots received glyphosate over-the-top of cotton at four growth stages (3-, 6-, 10-, and 14-leaf crop stages). Compared with Coker 312-1445, extended glyphosate resistance was expressed as higher yields when glyphosate was applied topically at the four growth stages. Mature plant mapping confirmed extended glyphosate resistance of the new transgenic cotton through similar fruit distribution and weight with or without glyphosate treatment. The capability to apply glyphosate topically to cotton later in crop development will facilitate weed management and could reduce dependence on directed herbicides. DA - 2004/// PY - 2004/// DO - 10.2135/cropsci2004.0234 VL - 44 IS - 1 SP - 234-240 ER - TY - JOUR TI - Timing defoliation applications for maximum yields and optimum quality in cotton containing a fruiting gap AU - Faircloth, J. C. AU - Edmisten, K. L. AU - Wells, R. AU - Stewart, A. M. T2 - Crop Science AB - Stresses during cotton ( Gossypium hirsutum L.) square and boll formation can result in fruit abscission from several continuous nodes, resulting in a fruiting gap on the plant. This gap may cause a shift in benchmarks for timing various agronomic practices aimed at maximizing cotton yield and optimizing quality. A cotton defoliation timing study was performed in 1999, 2000, and 2001 to (i) see if the creation of a fruiting gap would influence defoliation timing and to (ii) compare the use of the open boll percentage at defoliation (OBPD), nodes above cracked boll (NACB), and micronaire readings at defoliation as tools for timing defoliation. In late July or early August each year, a fruiting gap was created by physically removing fruit from several continuous nodes on plants. Plots were defoliated on the basis of various OBPD values. Upon defoliation, OBPD and NACB were taken and lint was retained to determine the micronaire at defoliation. In both 1999 and 2000, there was a yield advantage to delaying defoliation beyond 60 OBPD in treatments containing a gap. However, in 2001 there was no yield advantage to delaying defoliation. This may have been due to optimal late‐season growing conditions experienced in 2001. In years when micronaire readings are high, data suggested cotton not containing a fruiting gap is more likely to be above discount levels for high micronaire and should not be defoliated past 60 OBPD. In both 1999 and 2000, trends confirmed a direct relationship between OBPD and both yield and micronaire. Overall, these studies demonstrated that in some years, where no fruiting gaps exist, it might be possible to terminate cotton before the 60% open boll recommendation without sacrificing yields. These results would allow farmers to shift defoliation, and hence harvest, to a time when there are fewer risks of quality‐based discounts. While a significant interaction prohibited the examination of the use of micronaire at defoliation as a technique for timing defoliation, there did not appear to be a significant advantage to using either NACB or OBPD for timing defoliation. DA - 2004/// PY - 2004/// DO - 10.2135/cropsci2004.1580 VL - 44 IS - 1 SP - 158-164 ER - TY - JOUR TI - Registration of 'NC-Neuse' wheat AU - Murphy, JP AU - Navarro, RA AU - Leath, S AU - Bowman, DT AU - Weisz, PR AU - Ambrose, LG AU - Pate, MH AU - Fountain, MO T2 - CROP SCIENCE AB - Crop ScienceVolume 44, Issue 4 p. 1479-1480 Registration of Cultivar Registration of ‘NC-Neuse’ Wheat J.P. Murphy, Corresponding Author J.P. Murphy njpm@unity.ncsu.edu Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Corresponding author (njpm@unity.ncsu.edu)Search for more papers by this authorR.A. Navarro, R.A. Navarro Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorS. Leath, S. Leath Dep. of Plant Pathology, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorD.T. Bowman, D.T. Bowman Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorP.R. Weisz, P.R. Weisz Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorL.G. Ambrose, L.G. Ambrose Beaufort Co. CES, 155 Airport Rd., Washington, NC, 27889Search for more papers by this authorM.H. Pate, M.H. Pate MidState Mills, Inc., P.O. Box 350, Newton, NC, 28658Search for more papers by this authorM.O. Fountain, M.O. Fountain Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this author J.P. Murphy, Corresponding Author J.P. Murphy njpm@unity.ncsu.edu Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Corresponding author (njpm@unity.ncsu.edu)Search for more papers by this authorR.A. Navarro, R.A. Navarro Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorS. Leath, S. Leath Dep. of Plant Pathology, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorD.T. Bowman, D.T. Bowman Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorP.R. Weisz, P.R. Weisz Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorL.G. Ambrose, L.G. Ambrose Beaufort Co. CES, 155 Airport Rd., Washington, NC, 27889Search for more papers by this authorM.H. Pate, M.H. Pate MidState Mills, Inc., P.O. Box 350, Newton, NC, 28658Search for more papers by this authorM.O. Fountain, M.O. Fountain Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this author First published: 01 July 2004 https://doi.org/10.2135/cropsci2004.1479Citations: 17 Research supported in part by grants from the North Carolina Small Grains Growers Association, the North Carolina Foundation Seed Producers, Inc., and the North Carolina Crop Improvement Association. Registration by CSSA. 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Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume44, Issue4July–August 2004Pages 1479-1480 RelatedInformation DA - 2004/// PY - 2004/// DO - 10.2135/cropsci2004.1479 VL - 44 IS - 4 SP - 1479-1480 SN - 1435-0653 ER - TY - JOUR TI - Recurrent half-sib selection with testcross evaluation for increased oil content in soybean AU - Feng, L AU - Burton, JW AU - Carter, TE AU - Pantalone, VR T2 - CROP SCIENCE AB - Protein meal and oil are the two commodities produced from soybean [ Glycine max (L.) Merr.] that give the crop its value. Increasing seed concentrations of either or both may add value. Objectives of this study were to investigate the effectiveness of recurrent half‐sib selection for increased seed oil, to evaluate the effect of tester oil content on selection response, and to investigate testcross heterosis and inbreeding depression for seed oil content. A recurrent half–sib selection system was devised for soybean and selection for increased oil content was conducted in a population for seven and three cycles using a high and a low‐oil tester, respectively. The base population was a high‐oil composite with gray pubescence ( tt ) that was segregating for nuclear genetic ms 1 male sterility. In summer, the base population was planted in single plant hills and bordered with the tester ( Ms 1 Ms 1 TT ) in a random mating block in North Carolina. About 100 to 200 random male‐sterile plants with hybrid seeds were harvested. Half‐sib families derived from each male‐sterile plant were then grown in Puerto Rico in winter. At maturity, seeds from tawny plants (tester hybrid) were used to identify half‐sib families with high‐oil content. Corresponding gray plant hybrids from sib matings within the population were bulked to start the next cycle of selection. Random progenies from the base populations and selected progenies from each cycle of selection were evaluated in a replicated field experiment at three locations in North Carolina. Cycle × tester hybrids and cycle × cycle sib hybrids were also included in the tests. The results showed that oil content was significantly increased at a rate of 1.1 ± 0.2 g kg −1 cycle −1 in the high‐oil tester populations but not in the low‐oil tester populations. The realized heritability estimate for the high‐oil tester population was 0.12 ± 0.03. Evidence of heterosis indicated that some dominance effects on oil content existed. Dominance effects may affect the evaluation accuracy of the genotypes being tested. A high‐oil tester and high‐oil populations may have many common alleles resulting in less dominance and more additive effects in their hybrids. Consequently, a high‐oil tester can lead to better evaluation and selection precision, compared with a low‐oil tester which could mask additive effects and reduce selection precision. DA - 2004/// PY - 2004/// DO - 10.2135/cropsci2004.6300 VL - 44 IS - 1 SP - 63-69 SN - 0011-183X ER - TY - JOUR TI - RNA silencing in plants by the expression of siRNA duplexes AU - Lu, SF AU - Shi, R AU - Tsao, CC AU - Yi, XP AU - Li, LG AU - Chiang, VL T2 - NUCLEIC ACIDS RESEARCH AB - In animal cells, stable RNA silencing can be achieved by vector-based small interfering RNA (siRNA) expression system, in which Pol III RNA gene promoters are used to drive the expression of short hairpin RNA, however, this has not been demonstrated in plants. Whether Pol III RNA gene promoter is capable of driving siRNA expression in plants is unknown. Here, we report that RNA silencing was achieved in plants through stable expression of short hairpin RNA, which was driven by Pol III RNA gene promoters. Using glucuronidase (GUS) transformed tobacco as a model system, the results demonstrated that 21 nt RNA duplexes, targeting at different sites of GUS gene, were stably expressed under the control of either human H1 or Arabidopsis 7SL RNA gene promoter, and GUS gene was silenced in 80% of siRNA transgenics. The severity of silencing was correlated with the abundance of siRNA expression but independent of the target sites and uridine residue structures in siRNA hairpin transcripts. Thus, the specific expression of siRNA provides a new system for the study of siRNA silencing pathways and functional genomics in plants. Moreover, the effectiveness of the human H1 promoter in a plant background suggested a conserved mechanism underlying Pol III complex functionality. DA - 2004/// PY - 2004/// DO - 10.1093/nar/gnh170 VL - 32 IS - 21 SP - SN - 1362-4962 ER - TY - JOUR TI - Phosphorus and intraspecific density alter plant responses to arbuscular mycorrhizas AU - Schroeder, MS AU - Janos, DP T2 - PLANT AND SOIL DA - 2004/7// PY - 2004/7// DO - 10.1023/b:plso.0000047765.28663.49 VL - 264 IS - 1-2 SP - 335-348 SN - 1573-5036 KW - arbuscular mycorrhizas KW - growth depression KW - intraspecific competition KW - phosphorus availability KW - relative growth rates ER - TY - JOUR TI - Microstructure of peanut (Arachis hypogaea L. cv. 'NC 7') cotyledons during development AU - Young, CT AU - Pattee, HE AU - Schadel, WE AU - Sanders, TH T2 - LEBENSMITTEL-WISSENSCHAFT UND-TECHNOLOGIE-FOOD SCIENCE AND TECHNOLOGY AB - Peanut pods (Arachis hypogaea L. cv. ‘NC 7’) were sampled on a single harvest date. The fresh pods were opened, and the seeds were divided into four developmental categories: (1) very immature; (2) immature; (3) mature; and (4) very mature; according to interior pericarp surfaces, testa color and textural characteristics, and seed size and shape. Seeds for each developmental stage were processed for SEM and TEM evaluations of cotyledonary cells. The primary factors, namely, cell size and type of storage substances synthesized, which contributed to the differences occurring in the microstructure of cotyledonary cells at the selected developmental stages prior to and during maturation are described. DA - 2004/// PY - 2004/// DO - 10.1016/j.lwt.2003.10.016 VL - 37 IS - 4 SP - 439-445 SN - 0023-6438 KW - seed development KW - protein body KW - lipid body KW - starch grain ER - TY - JOUR TI - Influence of ozone on ribonuclease activity in wheat (Triticum aestivum) leaves AU - Booker, FL T2 - PHYSIOLOGIA PLANTARUM AB - Ribonucleases (RNases) degrade RNA and exert a major influence on gene expression during development and in response to biotic and abiotic stresses. RNase activity typically increases in response to pathogen attack, wounding and phosphate (P(i)) deficiency. Activity also increases during senescence and other programmed cell death processes. The air pollutant ozone (O(3)) often induces injury and accelerated senescence in many plants, but the biochemical mechanisms involved in these responses remain unclear. The objective of this study was to determine whether RNase activity and isozyme expression was stimulated in wheat (Triticum aestivum L.) flag leaves following treatment with O(3). Plants were treated in open-top chambers with charcoal-filtered air (27 nmol O(3) mol(-1)) (control) or non-filtered air plus O(3) (90 nmol O(3) mol(-1)) (O(3)) from seedling to reproductive stage. After exposure for 56 days, RNase activity was 2.1 times higher in flag leaf tissues from an O(3)-sensitive cultivar in the O(3) treatment compared with the control, which generally coincided with foliar injury and lower soluble protein concentration, but not soluble leaf [P(i)]. Soluble [P(i)] in leaf tissue extracts from the O(3) and control treatments was not significantly different. RNase activity gels indicated the presence of three major RNases and two nucleases, and their expression was enhanced by the O(3) treatment. Isozymes stimulated in the O(3) treatment were also stimulated in naturally senescent flag leaf tissues from plants in the control. However, soluble [P(i)] in extracts from naturally senescent flag leaves was 50% lower than that found in green flag leaves in the control treatment. Thus, senescence-like pathological responses induced by O(3) were accompanied by increased RNase and nuclease activities that also were observed in naturally senescent leaves. However, [P(i)] in the leaf tissue samples suggested that O(3)-induced injury and accelerated senescence was atypical of normal senescence processes in that P(i) export was not observed in O(3)-treated plants. DA - 2004/2// PY - 2004/2// DO - 10.1111/j.0031-9317.2004.0238.x VL - 120 IS - 2 SP - 249-255 SN - 0031-9317 ER - TY - JOUR TI - In-season optimization and site-specific nitrogen management for soft red winter wheat AU - Flowers, M AU - Weisz, R AU - Heiniger, R AU - Osmond, D AU - Crozier, C T2 - AGRONOMY JOURNAL AB - Site-specific N management based on an in-season assessment of crop N status may offer producers increased grain yield, profitability, and spring N fertilizer use efficiency (SNUE). The goal of this study was to determine the distinct contributions of (i) in-season N rate optimization and (ii) site-specific N management. Our objective was to compare site-specific and field-specific N management with typical growers' practices to determine if site-specific N management (i) increased soft red winter wheat (Triticum aestivum L.) grain yield, (ii) reduced N inputs, (iii) increased SNUE, and (iv) reduced within-field grain yield variability. Research was conducted at eight sites in 2000, 2001, and 2002. A randomized complete block design with two or five N management systems was used at two and six sites, respectively. Site-specific management did not improve grain yield compared with field-specific management when based on the same in-season estimation of optimum N rates. At sites where site-specific or field-specific systems were compared with typical growers' practices, grain yield benefits of in-season N optimization (up to 2267 kg ha−1) were apparent. For grain yield, in-season optimization of N rate was more important than site-specific management. A large reduction in N inputs (up to 48.6%) was also attributed to in-season N rate optimization. After incorporating in-season optimization, a further reduction in N inputs (up to 19.6%) was possible through site-specific application. Site-specific N application maximized SNUE compared with either field-specific or typical growers' practices at all sites and reduced within-field grain yield variance at four sites. DA - 2004/// PY - 2004/// DO - 10.2134/agronj2004.0124 VL - 96 IS - 1 SP - 124-134 SN - 1435-0645 ER - TY - JOUR TI - Gene expression during formation of earlywood and latewood in loblolly pine: Expression profiles of 350 genes AU - Egertsdotter, U AU - Zyl, LM AU - MacKay, J AU - Peter, G AU - Kirst, M AU - Clark, C AU - Whetten, R AU - Sederoff, R T2 - PLANT BIOLOGY AB - The natural variability of wood formation in trees affords opportunities to correlate transcript profiles with the resulting wood properties. We have used cDNA microarrays to study transcript abundance in developing secondary xylem of loblolly pine (Pinus taeda) over a growing season. The cDNAs were selected from a collection of 75 000 ESTs that have been sequenced and annotated (http://web.ahc.umn.edu/biodata/nsfpine/). Cell wall thickness and climatic data were related to earlywood and latewood formation at different time points during the growing season. Seventy-one ESTs showed preferential expression in earlywood or latewood, including 23 genes with no significant similarity to genes in GenBank. Seven genes involved in lignin synthesis were preferentially expressed in latewood. The studies have provided initial insights into the variation of expression patterns of some of the genes related to the wood formation process. DA - 2004/11// PY - 2004/11// DO - 10.1055/s-2004-830383 VL - 6 IS - 6 SP - 654-663 SN - 1438-8677 KW - microarray analysis KW - Pinus taeda KW - earlywood KW - latewood KW - transcript abundance ER - TY - JOUR TI - Establishment of seeded centipedegrass (Eremochloa ophiuroides) in utility turf areas AU - Gannon, TW AU - Yelverton, FH AU - Cummings, HD AU - McElroy, JS T2 - WEED TECHNOLOGY AB - Experiments were conducted to evaluate safety and effectiveness of herbicides during establishment of seeded centipedegrass. Centipedegrass tolerance to herbicides was evaluated at seeding and early postemergence. Imazapic at 105 g ai/ha, sulfometuron at 53 g ai/ha, or metsulfuron at 21 or 42 g ai/ha applied at seeding reduced centipedegrass ground cover compared with the nontreated. Imazapic at 18 or 35 g/ha or applications of atrazine or simazine at seeding did not reduce centipedegrass ground cover compared with the nontreated. Applications of chlorsulfuron plus mefluidide (7 + 140 g ai/ha) or metsulfuron at 21 or 42 g/ha applied 6 wk after seeding (WAS) centipedegrass (one-leaf to one-tiller growth stage) caused 20, 16, and 83% phytotoxicity, respectively, 56 d after treatment (DAT). Imazapic, sulfometuron, atrazine, or simazine applied 6 WAS caused <15% phytotoxicity 56 DAT. When large crabgrass and centipedegrass were seeded together, large crabgrass emergence was reduced 41% when atrazine (1,100 g ai/ha) was applied at seeding. Centipedegrass tiller production was reduced with increasing amounts of crabgrass. However, centipedegrass tiller production and ground cover were higher when atrazine was applied because of reduced interspecific interference from large crabgrass. These data indicate that centipedegrass can be established more quickly if appropriate herbicides are used at seeding or shortly after seeding. DA - 2004/// PY - 2004/// DO - 10.1614/WT-03-112R1 VL - 18 IS - 3 SP - 641-647 SN - 0890-037X KW - atrazine KW - chlorsulfuron KW - Digitaria sanguinalis KW - herbicide tolerance KW - imazapic KW - interference KW - large crabgrass KW - mefluidide KW - metsulfuron KW - PGR tolerance KW - simazine ER - TY - JOUR TI - Dissection of maize kernel composition and starch production by candidate gene association AU - Wilson, LM AU - Whitt, , SR AU - Ibanez, AM AU - Rocheford, TR AU - Goodman, MM AU - Buckler, ES T2 - PLANT CELL AB - Cereal starch production forms the basis of subsistence for much of the world's human and domesticated animal populations. Starch concentration and composition in the maize (Zea mays ssp mays) kernel are complex traits controlled by many genes. In this study, an association approach was used to evaluate six maize candidate genes involved in kernel starch biosynthesis: amylose extender1 (ae1), brittle endosperm2 (bt2), shrunken1 (sh1), sh2, sugary1, and waxy1. Major kernel composition traits, such as protein, oil, and starch concentration, were assessed as well as important starch composition quality traits, including pasting properties and amylose levels. Overall, bt2, sh1, and sh2 showed significant associations for kernel composition traits, whereas ae1 and sh2 showed significant associations for starch pasting properties. ae1 and sh1 both associated with amylose levels. Additionally, haplotype analysis of sh2 suggested this gene is involved in starch viscosity properties and amylose content. Despite starch concentration being only moderately heritable for this particular panel of diverse maize inbreds, high resolution was achieved when evaluating these starch candidate genes, and diverse alleles for breeding and further molecular analysis were identified. DA - 2004/10// PY - 2004/10// DO - 10.1105/tpc.104.025700 VL - 16 IS - 10 SP - 2719-2733 SN - 1532-298X ER - TY - JOUR TI - Developing temperate inbreds using tropical maize germplasm: Rationale, results, conclusions AU - Goodman, M. M. T2 - Maydica DA - 2004/// PY - 2004/// VL - 49 IS - 3 SP - 209-219 ER - TY - JOUR TI - Control of volunteer glyphosate-resistant cotton in glyphosate-resistant soybean AU - York, AC AU - Stewart, AM AU - Vidrine, PR AU - Culpepper, AS T2 - WEED TECHNOLOGY AB - Cotton boll weevil has been eradicated from much of the U.S. Cotton Belt. After eradication, a containment program is necessary to detect and destroy reintroduced boll weevils. Crops other than cotton are not monitored for boll weevil, hence fruit on volunteer glyphosate-resistant (GR) cotton in GR soybean could provide oviposition sites for boll weevils and allow the insects to build up undetected. An experiment was conducted at five locations to evaluate control of GR cotton and reduction in cotton fruit production by herbicides commonly used on GR soybean. Cotton control by preemergence (PRE) or postemergence (POST) herbicides alone was inconsistent across locations. Flumetsulam at 45 g ai/ha, imazaquin at 137 g ai/ha, and metribuzin at 360 g ai/ha plus chlorimuron at 60 g ai/ha applied PRE controlled cotton 55 to 100% and reduced cotton fruit production 84 to 100%. Sulfentrazone at 167 g ai/ha plus chlorimuron at 34 g/ha PRE controlled cotton 50 to 91% and reduced fruit 48 to 98%. Metribuzin PRE at 420 g/ha controlled cotton 23 to 97% and reduced fruit 32 to 100%. Flumiclorac at 30 g ai/ha, 2,4-DB dimethylamine salt at 35 g ae/ha, chlorimuron at 12 g ai/ha, and the sodium salt of fomesafen at 420 g ai/ha mixed with glyphosate and applied POST controlled cotton 48 to 100% and reduced fruit production 67 to 100%. Cloransulam at 12 or 18 g ai/ha controlled cotton 3 to 66% and reduced fruit production 5 to 85%. Cotton control and fruit reduction were greatest and most consistent with sequential applications of metribuzin plus chlorimuron PRE followed by chlorimuron, flumiclorac, fomesafen, or 2,4-DB POST. These treatments controlled cotton at least 95% at all locations. Cotton fruit was totally eliminated at three locations and reduced at least 97% at a fourth location. DA - 2004/// PY - 2004/// DO - 10.1614/WT-03-073R1 VL - 18 IS - 3 SP - 532-539 SN - 0890-037X KW - boll weevil eradication KW - chlorimuron KW - cloransulam KW - flumetsulam KW - flumiclorac KW - fomesafen KW - metribuzin KW - oviposition sites KW - sulfentrazone KW - 2,4-DB ER - TY - JOUR TI - Control of silvery-thread moss (Bryum argenteum Hedw.) in creeping bentgrass (Agrostis palustris Huds.) putting greens AU - Burnell, KD AU - Yelverton, FH AU - Neal, JC AU - Gannon, TW AU - McElroy, JS T2 - WEED TECHNOLOGY AB - Field experiments were conducted to evaluate chemicals for silvery-thread moss control and bentgrass turfgrass quality. Treatments included iron (Fe)-containing products, nitrogen fertilizers, Ultra Dawn dishwashing detergent (UD) at 3% (v/v), and oxadiazon. In general, greater silvery-thread moss control was achieved with Fe-containing products. Ferrous sulfate at 40 kg Fe/ha plus ammonium sulfate at 30 kg N/ha, a combined product of ferrous oxide, ferrous sulfate, and iron humates (FEOSH) at 125 kg Fe/ha, and a combined product of iron disulfide and ferrous sulfate (FEDS) at 112 kg Fe/ha reduced silvery-thread moss populations 87, 81, and 69%, respectively, 6 wk after initial treatment (WAIT). UD reduced silvery-thread moss populations 57% 6 WAIT. The addition of oxadiazon to Fe-containing treatments did not improve silvery-thread moss population reduction. Other experiments evaluated two formulations of chlorothalonil, each applied at two rates, chlorothalonil with zinc at 9.5 and 17.4 kg ai/ha and chlorothalonil without zinc at 9.1 and 18.2 kg/ ha, and two spray volumes (2,038 and 4,076 L/ha). Greater silvery-thread moss population reduction was observed at Jefferson Landing in 1999 compared with Elk River in 1999 and 2000. Rainfall events at Elk River in 1999 and 2000 within 24 h after application and no rain at Jefferson Landing may account for variation in performance of products between sites. However, no difference in chlorothalonil formulation, rate, or spray volume was observed in any location or year. These data indicate that Fe-containing fertilizers or chlorothalonil can be used to reduce silvery-thread moss populations in creeping bentgrass putting greens. DA - 2004/// PY - 2004/// DO - 10.1614/WT-03-082R1 VL - 18 IS - 3 SP - 560-565 SN - 1550-2740 KW - bryology KW - moss control KW - turfgrass injury ER - TY - JOUR TI - Calibrating hydric soil field indicators to long-term wetland hydrology AU - Vepraskas, MJ AU - He, X AU - Lindbo, DL AU - Skaggs, RW T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - Jurisdictional wetlands are required to be saturated to the surface for 5% or more of the growing season in 5 out of 10 yr, but practical field methods for confirming this are lacking. This study determined whether hydric soil field indicators were related to wetland hydrology requirements. Water table levels were monitored daily for 2.5 yr in a toposequence of nine soil plots that included well to poorly drained members (Oxyaquic Paleudults and Typic Albaqualfs). Monitoring data were used to calibrate a hydrologic model that simulated water table levels from inputs of hourly rainfall data. Forty years of rainfall data were then used with the model to compute long‐term daily water‐table levels in each plot. These data were summarized as “saturation events”, which are the frequency that water tables were at or above preselected depths for at least 21 d. Twenty‐one days was the average period needed for Fe reduction to begin in these saturated soils. This condition must occur for hydric soil field indicators to form. Regression equations were developed to relate saturation events to percentages of redoximorphic features. The r 2 values for relationships between percentages of redoximorphic features and saturation events were >0.80 for depths of 15 cm, and >0.90 for depths between 30 and 90 cm. Results showed that the depleted matrix field indicator, in which redox depletions occupy >60% of the horizon, occurred in soils that were saturated for 21 d or longer at least 9 yr out of 10. This indicated the depleted matrix indicator occurred in soils that were saturated nearly twice as long, and more frequently, than the minimum requirements needed to meet wetland hydrology requirements. DA - 2004/// PY - 2004/// DO - 10.2136/sssaj2004.1461 VL - 68 IS - 4 SP - 1461-1469 SN - 0361-5995 ER - TY - JOUR TI - Wheat tolerance to AE f130060 00 plus AE f115008 00 as affected by time of application and rate of the safener AE F107892 AU - Crooks, HL AU - York, AC AU - Jordan, DL T2 - WEED TECHNOLOGY AB - Soft red winter wheat response to the herbicides AE F130060 00 plus AE F115008 00 applied alone or with the safener AE F107892 at the three-leaf, two-tiller, and six-tiller growth stages was determined in a field experiment in North Carolina. AE F130060 00 at 25 g ai/ha plus AE F115008 00 at 5 g ai/ha, twice the anticipated use rate, applied with safener injured wheat 9% but did not affect grain yield, grain test weight, number of spikes, number of kernels per spike, or kernel weight. Results were similar with safener at herbicide–safener ratios of 1:1 and 1:3 regardless of the wheat growth stage at application. Without the safener, AE F130060 00 plus AE F115008 00 applied at the three-leaf, two-tiller, and six-tiller growth stages injured wheat an average of 27% and reduced grain yields 5, 5, and 11%, respectively. Yield losses were attributed to reduced numbers of kernels per spike. AE F130060 00 at 12.5 g/ha plus AE F115008 00 at 2.5 g/ha plus AE F107892 at 15 g ai/ha did not affect grain yield or yield components. DA - 2004/// PY - 2004/// DO - 10.1614/WT-03-122R1 VL - 18 IS - 3 SP - 841-845 SN - 1550-2740 KW - herbicide injury KW - wheat yield KW - yield components ER - TY - JOUR TI - Nitrogen mineralization of anaerobic swine lagoon sludge as influenced by seasonal temperatures AU - Moore, AD AU - Mikkelsen, RL AU - Israel, DW T2 - COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS AB - Abstract As anaerobic swine lagoons approach maximum sludge storage capacity, producers must periodically remove sludge and apply it to nearby fields. Information regarding the availability of nitrogen (N) in sludge as a nutrient source applied at different seasons of the year could improve crop-use efficiency. A 12-month laboratory study was conducted to quantify the effects of seasonal temperatures on mineralization of N in lagoon sludge. Sludge was mixed with a Coastal Plain soil (Arenic Kandiudult) and incubated for one year at weekly fluctuating temperatures based on Winter, Spring, Summer, and Fall application dates, ranging from a Winter low temperature of 9°C to a Summer maximum temperature of 30°C. Samples were analyzed monthly for NO3-N and NH4-N in 1.0 M KCl extracts of sludge amended soil. Sludge N availability (sum of NO3-N plus NH4-N concentration in 1.0 M KCl extract) was fit to a nonlinear regression model for a first-order reaction. Net N mineralization rate constants (k) derived from these models for the initial season of application increased in the order Fall (0.07) < Winter (0.075) < Spring (0.22) < Summer (0.36). While initial rates of net N mineralization differed, N availability predicted from first order equations was similar for all temperature regimes after one year of incubation and averaged 74% of the total N applied. Forty-two to 53% of the organic N in the sludge was mineralized during the one-year incubation. DA - 2004/4// PY - 2004/4// DO - 10.1081/CSS-120030575 VL - 35 IS - 7-8 SP - 991-1005 SN - 1532-2416 ER - TY - JOUR TI - Effects of bridge shading on estuarine marsh benthic invertebrate community structure and function AU - Struck, SD AU - Craft, CB AU - Broome, SW AU - Sanclements, MD AU - Sacco, JN T2 - ENVIRONMENTAL MANAGEMENT DA - 2004/7// PY - 2004/7// DO - 10.1007/s00267-004-0032-y VL - 34 IS - 1 SP - 99-111 SN - 0364-152X KW - bridge shading KW - light attenuation KW - benthic invertebrates KW - North Carolina KW - ecosystem structure and function KW - human impacts KW - coastal wetlands ER - TY - JOUR TI - Dissolution of trace element contaminants from two coastal plain soils as affected by pH AU - Bang, JS AU - Hesterberg, D T2 - JOURNAL OF ENVIRONMENTAL QUALITY AB - ABSTRACT Trace element mobility in soils depends on contaminant concentration, chemical speciation, water movement, and soil matrix properties such as mineralogy, pH, and redox potential. Our objective was to characterize trace element dissolution in response to acidification of soil samples from two abandoned incinerators in the North Carolina Coastal Plain. Trace element concentrations in 11 soil samples from both sites ranged from 2 to 46 mg Cu kg −1 , 3 to 105 mg Pb kg −1 , 1 to 102 mg Zn kg −1 , 3 to 11 mg Cr kg −1 , <0.1 to 10 mg As kg −1 , and <0.01 to 0.9 mg Cd kg −1 Acidified CaCl 2 solutions were passed through soil columns to bring the effluent solution to approximately pH 4 during a 280‐h flow period. Maximum concentrations of dissolved Cu, Pb, and Zn at the lowest pH of an experiment (pH 3.8–4.1) were 0.32 mg Cu L −1 , 0.11 mg Pb L −1 , and 1.3 mg Zn L −1 for samples from the site with well‐drained soils, and 0.25 mg Cu L −1 , 1.2 mg Pb L −1 , and 1.4 mg Zn L −1 for samples from the site with more poorly drained soils. Dissolved Cu concentration at pH 4 increased linearly with increasing soil Cu concentration, but no such relationship was found for Zn. Dissolved concentrations of other trace elements were below our analytical detection limits. Synchrotron X‐ray absorption near edge structure (XANES) spectroscopy showed that Cr and As were in their less mobile Cr(III) and As(V) oxidation states. XANES analysis of Cu and Zn on selected samples indicated an association of Cu(II) with soil organic matter and Zn(II) with Al‐ and Fe‐oxides or franklinite. DA - 2004/// PY - 2004/// DO - 10.2134/jeq2004.0891 VL - 33 IS - 3 SP - 891-901 SN - 1537-2537 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-2442655324&partnerID=MN8TOARS ER - TY - JOUR TI - Dispersion of natural arsenic in the Malcantone watershed, Southern Switzerland: field evidence for repeated sorption-desorption and oxidation-reduction processes AU - Pfeifer, HR AU - Gueye-Girardet, A AU - Reymond, D AU - Schlegel, C AU - Temgoua, E AU - Hesterberg, DL AU - Chou, JWQ T2 - GEODERMA AB - In recent years, elevated arsenic concentrations have been found in waters and soils of many countries, often resulting in a health threat for the local population. Switzerland is not an exception and this paper deals with the release and subsequent fate of arsenic in a 200-km2 mountainous watershed, characterized by crystalline silicate rocks (gneisses, schists, amphibolites) that contain abundant As-bearing sulfide ore deposits, some of which have been mined for iron and gold in the past. Using analytical methods common for mineralogical, ground water and soil studies (XRD, XRF, XAS-XANES and -EXAFS, electron microprobe, extraction, ICP, AAS with hydride generator, ion chromatography), seven different field situations and related dispersion processes of natural arsenic have been studied: (1) release by rock weathering; (2) transport and deposition by water and ice; (3) release of As to the ground and surface water due to increasing pH; (4) accumulation in humic soil horizons; (5) remobilization by reduction in water-saturated soils and stagnant ground waters; (6) remobilization by using P-rich fertilizers or dung and (7) oxidation, precipitation and dilution in surface waters. Comparison of the results with experimental adsorption studies and speciation diagrams from the literature allows us to reconstruct and identify the typical behavior of arsenic in a natural environment under temperate climatic conditions. The main parameters identified are: (a) once liberated from the primary minerals, sorption processes on Fe-oxy-hydroxides dominate over Al-phases, such as Al-hydroxides or clay minerals and limit the As concentrations in the spring and well waters between 20 and 300 μg/l. (b) Precipitation as secondary minerals is limited to the weathering domain, where the As concentrations are still high and not yet too diluted by rain and soils waters. (c) Although neutral and alkaline pH conditions clearly increase the mobility of As, the main factor to mobilize As is a low redox potential (Eh close or below 0 mV), which favors the dissolution of the Fe-oxy-hydroxides on which the As is sorbed. (d) X-ray absorption spectroscopy (XAS) of As in water-logged humic forest soils indicates that the reduction to As III only occurs at the solid–water interface and that the solid contains As as As V. (e) A and Bh horizons of humic cambisols can effectively capture As when As-rich waters flow through them. Complex spatial and temporal variation of the various parameters in a watershed results in repeated mobilization and immobilization of As, which continuously transports As from the upper to the lower part of a watershed and ultimately to the ocean. DA - 2004/10// PY - 2004/10// DO - 10.1016/j.geoderma.2004.01.009 VL - 122 IS - 2-4 SP - 205-234 SN - 1872-6259 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-4444339983&partnerID=MN8TOARS KW - arsenic KW - groundwater KW - soil KW - sorption KW - weathering KW - X-ray absorption spectroscopy ER - TY - JOUR TI - Direct observations of the effects of aerosol loading on net ecosystem CO2 exchanges over different landscapes AU - Niyogi, D AU - Chang, HI AU - Saxena, VK AU - Holt, T AU - Alapaty, K AU - Booker, F AU - Chen, F AU - Davis, KJ AU - Holben, B AU - Matsui, T AU - Meyers, T AU - Oechel, WC AU - Pielke, RA AU - Wells, R AU - Wilson, K AU - Xue, YK T2 - GEOPHYSICAL RESEARCH LETTERS AB - We present the first direct, multisite observations in support of the hypothesis that atmospheric aerosols affect the regional terrestrial carbon cycle. The daytime growing season (summer) CO 2 flux observations from six sites (forest, grasslands, and croplands) with collocated aerosol and surface radiation measurements were analyzed for high and low diffuse radiation; effect of cloud cover; and effect of high and low aerosol optical depths (AOD). Results indicate that, aerosols exert a significant impact on net CO 2 exchange, and their effect may be even more significant than that due to clouds. The response appears to be a general feature irrespective of the landscape and photosynthetic pathway. The CO 2 sink increased with aerosol loading for forest and crop lands, and decreased for grassland. The cause for the difference in response between vegetation types is hypothesized to be canopy architecture. DA - 2004/10/29/ PY - 2004/10/29/ DO - 10.1029/2004gl020915 VL - 31 IS - 20 SP - SN - 0094-8276 ER - TY - JOUR TI - Characterization of turf practices in five North Carolina communities AU - Osmond, DL AU - Hardy, DH T2 - JOURNAL OF ENVIRONMENTAL QUALITY AB - Limited information exists on specific urban lawn care practices in the United States. We conducted a door-to-door lawn care survey in five North Carolina communities to determine suburban fertilizer, pesticide, and water use. These communities, Cary, Goldsboro, Kinston, New Bern, and Greenville, are mostly located within the Neuse River basin, a nutrient-sensitive water resource. Residents in Cary used lawn care companies more than twice as frequently as residents in the other communities (43 compared with 20%). Cary had the smallest mean lawn size (445 m2), while the largest was in Goldsboro (1899 m2). Tall fescue [Festuca arundinacea Schreb.] was the predominant grass type in Cary (99%), and centipedegrass [Eremochloa ophiuroides (Munro) Hack.] or centipedegrass mixtures were the predominant grass types in Greenville and New Bern. Kinston had the lowest fertilizer usage with only 54% of the residents using fertilizer; Cary had the highest rate of 83%. The average N fertilizer rate applied to the lawns was dissimilar ranging from 24 to 151 kg N ha−1 Analysis of variance results for fertilizer rates and household income indicated a significant difference (P < 0.05) in application rate between high- and medium-income levels and the low-income level. Cary, Goldsboro, and Greenville had approximately the same number of fertilizer applications per year (1.5), whereas the average number of fertilizer applications per year in New Bern was 3.0. Most household residents (53%) used instructions on the bag and either grass type and/or lawn area to guide them on fertilizer application rates. DA - 2004/// PY - 2004/// DO - 10.2134/jeq2004.0565 VL - 33 IS - 2 SP - 565-575 SN - 1537-2537 ER - TY - JOUR TI - A major QTL conditioning salt tolerance in S-100 soybean and descendent cultivars AU - Lee, GJ AU - Boerma, HR AU - Villagarcia, MR AU - Zhou, X AU - Carter, TE AU - Li, Z AU - Gibbs, MO T2 - THEORETICAL AND APPLIED GENETICS DA - 2004/11// PY - 2004/11// DO - 10.1007/s00122-004-1783-9 VL - 109 IS - 8 SP - 1610-1619 SN - 1432-2242 ER - TY - JOUR TI - Physical properties of three sand size classes amended with inorganic materials or sphagnum peat moss for putting green rootzones AU - Bigelow, CA AU - Bowman, DC AU - Cassel, DK T2 - CROP SCIENCE AB - Modern putting green rootzones are typically constructed using sands to avoid compaction and facilitate rapid drainage. Sands are often amended with organic matter (OM) such as sphagnum peat moss (SP) to increase moisture holding capacity. However, OM decomposition into finely divided material may negatively affect long-term soil physical properties. Inorganic amendments (IAs) having high water retention may be more suitable because of their resistance to biodegradation. A laboratory study determined the physical properties [bulk density, saturated hydraulic conductivity (Ksat), water retention, and pore size distribution] of three USDA sand size classes (fine, medium, and coarse) with and without amendment. Amendments used were calcined clay, vitrified clay, extruded diatomaceous earth, a processed zeolite, and SP. Amendments were tested at two incorporation rates (10 and 20% v/v), and in situ in 30-cm-deep rootzones at two incorporation depths (15 and 30 cm). Bulk density decreased, total porosity increased, and Ksat declined with amendment rate, but varied considerably depending on amendment, sand size, and incorporation depth. The Ksat was high for all mixtures, averaging 250 cm h−1, probably because of the very uniform sands. On the basis of standard pressure plate methods, IAs increased total water holding capacity (WHC) of all three sands but did not increase available water. However, a unique bioassay for available water indicated that porous IAs may contain appreciably more available water than measured by the pressure plate technique. Although the IAs significantly altered the physical properties of the three sands, they were not as effective as SP at improving water retention in coarse-textured, drought-prone sands. DA - 2004/// PY - 2004/// DO - 10.2135/cropsci2004.0900 VL - 44 IS - 3 SP - 900-907 SN - 0011-183X ER - TY - CHAP TI - Perchlorate in fertilizer? A product defense story AU - Weber, L. D. AU - Robarge, W. P. AU - Hall, W. L. AU - Averitt, D. T2 - Environmental impact of fertilizer on soil and water AB - In 1999, a paper entitled Perchlorate Identification In Fertilizers was published which implicated a number of lawn and garden fertilizers and fertilizer source materials as containing perchlorate (1). After re-analyzing these samples using unproved sampling and analytical protocols, most of the fertilizer source materials were found not to contain perchlorate (non-detectable amounts). Perchlorate was still present, to a lesser extent, in several fertilizer source materials and all of the original lawn and garden products. However, no perchlorate has been found in any subsequent analyses of the same products that were later purchased (2). To further investigate this issue, IMC-Global, the world's largest producer and marketer of concentrated phosphate and potash crop nutrients for the agricultural industry, initiated its own analysis program to survey for the possible presence of perchlorate in fertilizer source materials and lawn and garden products, and in samples archived as part of its quality control program. Additional historical samples were recovered from the Magruder check sample program managed through AAPFCO (3). Lastly, IMC Global also participated in several round-robin studies organized by the US Environmental Protection Agency and The Fertilizer Institute (4) to systematically evaluate whether perchlorate does or should be expected to occur in fertilizers. CN - S633 .E7 2004 PY - 2004/// DO - 10.1021/bk-2004-0872.ch003 VL - 872 SP - 32-44 PB - Washington, D.C.: Transportation Research Board ER - TY - JOUR TI - Oil, sugar, and starch characteristics in peanut breeding lines selected for low and high oil content and their combining ability AU - Isleib, TG AU - Pattee, HE AU - Giesbrecht, FG T2 - JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY AB - Peanut seeds contain approximately 50% oil on a dry weight basis, making them a high fat food. Reduction of the oil content would make peanuts a more desirable food to fat conscious consumers. Removal of existing oil by processing is not feasible for in-shell peanuts, the dominant product of the North Carolina-Virginia area. To reduce oil content in in-shell peanuts, a genetic solution must be found. However, while reduced oil content is a desirable objective, changes in oil must not be accompanied by significant decreases in any of the desirable aspects of peanut flavor. Because the impact of selection for low or high oil on flavor is not known, it would be useful to know in what form dry matter is being stored in the seed, particularly if it is not being stored as oil. Screening of 584 accessions identified two lines (PI 269723 and PI 315608) with high and two (Robusto 2 and Robusto 3) with low oil contents, each pair differing in sugar content. The four parents were crossed in diallel fashion to investigate patterns of inheritance. General combining abilities (GCA) for oil content closely followed values of the parental lines. One low oil parent (Robusto 2) had a correspondingly elevated GCA for sugar content, but neither low oil parent had the effect of elevating starch in progeny. Reciprocal cross differences were found for starch and sugar contents, suggesting influences of cytoplasmic genes on those traits. These lines serve as resource material for researchers interested in the genetic and physiological aspects of the oil-sugar-starch relationship in peanuts. DA - 2004/5/19/ PY - 2004/5/19/ DO - 10.1021/jf035465y VL - 52 IS - 10 SP - 3165-3168 SN - 1520-5118 KW - general combining ability KW - GCA KW - specific combining ability KW - SCA KW - maternal effect KW - reciprocal effect ER - TY - JOUR TI - Influence of photoperiod and temperature on vegetative growth and development of Florida betony (Stachys floridana) AU - McElroy, JS AU - Yelverton, FH AU - Neal, JC AU - Rufty, TW T2 - WEED SCIENCE AB - Experiments were conducted in environmental chambers to the evaluate effects of photoperiod and temperature on Florida betony growth and development. Plants were exposed to two photoperiods, short day (9 h) and long day (9 + 3 h night interruption), and three day/night temperature regimes, 18/14, 22/18, and 26/22 C. After 10 wk of growth, shoot length and weight were 3.4 and 3.5 times greater, respectively, in the long-day photoperiod and with the 26 and 22 than with the 22 and 18 C day and night temperature regime, respectively. Shoot number, however, was greatest in the short-day photoperiod and at a lower temperature of 22/18 C. Shoot number in long day 22/18 C and 26/22 C environments increased asymptotically. No difference in root weight was observed between long- and short-day environments, but root weight increased with increasing temperature. Flowering and tuber production only occurred in long-day environments, with greater production of both at higher temperatures. Results provide a general framework for understanding Florida betony growth and development characteristics in the field and provide insights that should be considered in developing control strategies. DA - 2004/// PY - 2004/// DO - 10.1614/WS-03-045R VL - 52 IS - 2 SP - 267-270 SN - 1550-2759 KW - day length KW - tuber formation KW - weed biology ER - TY - JOUR TI - Growths nitrogen uptake, and metabolism in two semiarid shrubs grown at ambient and elevated atmospheric CO2 concentrations: Effects of nitrogen supply and source AU - Causin, HF AU - Tremmel, DC AU - Rufty, TW AU - Reynolds, JE T2 - AMERICAN JOURNAL OF BOTANY AB - The effect of differences in nitrogen (N) availability and source on growth and nitrogen metabolism at different atmospheric CO(2) concentrations in Prosopis glandulosa and Prosopis flexuosa (native to semiarid regions of North and South America, respectively) was examined. Total biomass, allocation, N uptake, and metabolites (e.g., free NO(3)(-), soluble proteins, organic acids) were measured in seedlings grown in controlled environment chambers for 48 d at ambient (350 ppm) and elevated (650 ppm) CO(2) and fertilized with high (8.0 mmol/L) or low (0.8 mmol/L) N (N(level)), supplied at either 1 : 1 or 3 : 1 NO(3)(-) : NH(4)(+) ratios (N(source)). Responses to elevated CO(2) depended on both N(level) and N(source), with the largest effects evident at high N(level). A high NO(3)(-) : NH(4)(+) ratio stimulated growth responses to elevated CO(2) in both species when N was limiting and increased the responses of P. flexuosa at high N(level). Significant differences in N uptake and metabolites were found between species. Seedlings of both species are highly responsive to N availability and will benefit from increases in CO(2), provided that a high proportion of NO(3)- to NH(4)-N is present in the soil solution. This enhancement, in combination with responses that increase N acquisition and increases in water use efficiency typically found at elevated CO(2), may indicate that these semiarid species will be better able to cope with both nutrient and water deficits as CO(2) levels rise. DA - 2004/4// PY - 2004/4// DO - 10.3732/ajb.91.4.565 VL - 91 IS - 4 SP - 565-572 SN - 1537-2197 KW - ammonium KW - CO2 KW - controlled environments KW - nitrate KW - nitrogen metabolism KW - nitrogen uptake KW - Prosopis flexuosa KW - Prosopis glandulosa ER - TY - JOUR TI - First report of Sclerotium rolfsii on common chickweed in North Carolina. AU - Hollowell, JE AU - Shew, BB T2 - PLANT DISEASE AB - Common chickweed (Stellaria media (L.) Cyrillo) is a common weed species found in agricultural fields of northeastern North Carolina. Symptomatic plants of common chickweed were observed during a March 2001 survey of winter annual weed species in Perquimans County, NC. The plants were growing in a harvested peanut field with a known history of southern stem rot caused by Sclerotium rolfsii Sacc. Water-soaked, bleached stems and chlorotic leaves were collected from plants and brought to the laboratory for isolation. Small portions (1 to 2 cm) of symptomatic stems and entire leaves were rinsed with tap water and placed on potato dextrose agar (PDA). Developing colonies were transferred to obtain pure cultures. The rapidly growing cultures had coarse, white mycelium typical of S. rolfsii and produced abundant, small, round, brown sclerotia approximately 2.0 mm in diameter on the surface of the culture. Clamp connections were observed with microscopic examination of mycelia. Pathogenicity of isolates was tested by placing 4-mm-diameter agar plugs of 2-day-old fungal mycelium on stems of three mature, nonsymptomatic chickweed plants. Agar plugs without fungal mycelium were used for the control treatment. Plugs were held in place with self-sticking bandage gauze. Plants were misted with water, enclosed in plastic bags, and incubated on a laboratory counter top at ambient temperature (24°C). Abundant mycelia developed, and water-soaked lesions and necrotic stems were observed. Noninoculated plants remained healthy and free of signs and symptoms during the incubation period. The fungus was reisolated on PDA, and pure cultures of S. rolfsii were obtained. Koch's postulates confirmed common chickweed was a host of S. rolfsii. To our knowledge, this is the first report of common chickweed as a host of S. rolfsii. Crop species commonly used in peanut rotations (corn, small grains, sorghum, and cotton) do not support populations of S. rolfsii. Many dicotyledonous weed species have been reported as hosts of S. rolfsii, but our observation of active disease on a winter weed species was unexpected. Colonization of winter weed, if prevalent, may enhance survival of S. rolfsii between crops of susceptible hosts such as peanut. DA - 2004/4// PY - 2004/4// DO - 10.1094/PDIS.2004.88.4.426B VL - 88 IS - 4 SP - 426-426 SN - 1943-7692 ER - TY - CHAP TI - Determination of trace metal content of fertilizer source materials produced in north America AU - Robarge, W. P. AU - Boos, D. AU - Proctor, C. T2 - Environmental impact of fertilizer on soil and water AB - There is increasing concern over the trace metal content of fertilizers and their subsequent application to agricultural and urban lands. It is feared that continued addition of trace metals to soils via fertilizers poses potential risks to farm families and to consumers of farm products. In order to assess this potential risk, it is necessary to know the trace metal content of fertilizer source materials. This study was undertaken to generate a statistically valid sampling of fertilizer source material produced in North America, and to determine the trace metal content (As, Cd, Cr, Cu, Mo, Ni, Pb, Se, V, U and Zn) of the resulting composite samples generated by the sampling protocol using modern analytical instrumentation and accepted good laboratory practices. The results support the general hypothesis that phosphate bearing source materials do contain varying levels of trace metals. The results also demonstrate that non-phosphate bearing N-P-K source materials do not contain significant amounts of trace metals and should not be considered significant sources of metals when added to agricultural or urban soils. Agreement of analyses from an interlaboratory comparison demonstrate the suitability of the analytical protocols used in this study. CN - S633 .E7 2004 PY - 2004/// DO - 10.1021/bk-2004-0872.ch006 VL - 872 SP - 75-89 PB - Washington, D.C.: Transportation Research Board ER - TY - JOUR TI - Crimson: A novel sex-linked eye color mutant of Culex pipiens L. (Diptera : Culicidae) AU - Rasgon, JL AU - Scott, TW T2 - JOURNAL OF MEDICAL ENTOMOLOGY AB - Xanthommatin is the primary ommochrome eye pigment in mosquitoes. The terminal step in xanthommatin biosynthesis, involving oxidation of 3-hydroxykynurenine (3HK), can proceed enzymatically by phenoxazinone synthase or by nonenzymatic auto-oxidation of 3HK. The relative contributions of these pathways, however, are unclear. We isolated a novel Culex pipiens mutant (crimson) that could be used to address this question. Homozygous crimson embryos exhibit no visible eyespot; first-instar larval ocelli are colorless. Eyes gradually turn red through immature development. Teneral crimson adults possess red eyes that darken to wild-type ≈5 d after emergence. Crosses indicate that crimson is sex-linked and fully recessive. Addition of xanthommatin precursors to rearing water did not rescue wild-type phenotype and suggested that the mutation is in the terminal step of ommochrome biosynthesis. Crimson expression was not temperature sensitive. Thin-layer chromatography demonstrated teneral crimson adults lacked xanthommatin. Teneral and aged wild-type adults exhibited low-mobility black ommochrome spots; aged crimson adults exhibited low-mobility brown-red ommochrome spots. Absorbance spectroscopy of eye extracts indicated teneral adult crimson eyes lacked xanthommatin but had abnormally high levels of 3HK, whereas extracts of 10-d-old crimson adults had depleted levels of 3HK and detectable levels of xanthommatin. Light microscopy indicated that eyes of young (3 d old) wild-type adults had a high concentration of pigment granules. Eyes of teneral crimson adults had no pigment granules. Eyes of 20-d-old crimson adults had low levels of pigment granules. We suggest two possible mechanisms for the crimson mutation: (1) transport of 3HK into the pigment cells and/or pigment granules is slow, with normal oxidation of 3HK into xanthommatin, or (2) 3HK is transported normally into pigment cells/granules but is not immediately oxidized to xanthommatin, resulting in 3HK hyper-accumulation and slow nonenzymatic production of xanthommatin after adult emergence. DA - 2004/5// PY - 2004/5// DO - 10.1603/0022-2585-41.3.385 VL - 41 IS - 3 SP - 385-391 SN - 1938-2928 KW - Culex pipiens KW - eye color mutant KW - ommochrome KW - 3-hydroxykynurenine KW - xanthommatin ER - TY - JOUR TI - Avian pluripotent stem cells AU - Petitte, JN AU - Liu, G AU - Yang, Z T2 - MECHANISMS OF DEVELOPMENT AB - Pluripotent embryonic stem cells are undifferentiated cells capable of proliferation and self-renewal and have the capacity to differentiate into all somatic cell types and the germ line. They provide an in vitro model of early embryonic differentiation and are a useful means for targeted manipulation of the genome. Pluripotent stem cells in the chick have been derived from stage X blastoderms and 5.5 day gonadal primordial germ cells (PGCs). Blastoderm-derived embryonic stem cells (ESCs) have the capacity for in vitro differentiation into embryoid bodies and derivatives of the three primary germ layers. When grafted onto the chorioallantoic membrane, the ESCs formed a variety of differentiated cell types and attempted to organize into complex structures. In addition, when injected into the unincubated stage X blastoderm, the ESCs can be found in numerous somatic tissues and the germ line. The potential give rise to somatic and germ line chimeras is highly dependent upon the culture conditions and decreases with passage. Likewise, PGC-derived embryonic germ cells (EGCs) can give rise to simple embryoid bodies and can undergo some differentiation in vitro. Interestingly, chicken EG cells contribute to somatic lineages when injected into the stage X blastoderm, but only germ line chimeras have resulted from EGCs injected into the vasculature of the stage 16 embryo. To date, no lines of transgenic chickens have been generated using ESCs or EGCs. Nevertheless, progress towards the culture of avian pluripotent stem cells has been significant. In the future, the answers to fundamental questions regarding segregation of the avian germ line and the molecular basis of pluripotency should foster the full use of avian pluripotent stem cells. DA - 2004/9// PY - 2004/9// DO - 10.1016/j.mod.2004.05.003 VL - 121 IS - 9 SP - 1159-1168 SN - 1872-6356 KW - chick KW - avian KW - embryonic stem cells KW - embryonic germ cells KW - primordial germ cells KW - chimeras ER - TY - JOUR TI - Weed management in glyphosate-resistant corn with glyphosate and halosulfuron AU - Thomas, WE AU - Burke, IC AU - Wilcut, JW T2 - WEED TECHNOLOGY AB - Three field studies were conducted at Lewiston Woodville, NC, in 2001 and 2002 to evaluate crop tolerance, weed control, grain yield, and net returns in glyphosate-resistant corn with various herbicide systems. Crop injury, weed control, and grain yield were not influenced by glyphosate formulation. Atrazine preemergence (PRE) and atrazine plus metolachlor PRE, averaged over postemergence (POST) systems, controlled Texas panicum at least 80 and 87%, respectively. Sequential glyphosate applications (early postemergence [EPOST] followed by [fb] POST) provided at least 99% control of Texas panicum compared with at least 86 and 88% control with glyphosate EPOST and glyphosate plus halosulfuron EPOST, respectively. Atrazine plus metolachlor PRE fb any glyphosate system controlled large crabgrass and goosegrass 89 to 100% and 94 to 100%, respectively. Sequential glyphosate treatments controlled large crabgrass and goosegrass at least 99 and 95%, respectively. Regardless of PRE system, glyphosate plus halosulfuron EPOST and sequential applications of glyphosate controlled common ragweed and common lambsquarters at least 99%, whereas glyphosate EPOST alone provided at least 88 and 96% control, respectively. Glyphosate plus halosulfuron EPOST and glyphosate sequentially controlled yellow nutsedge similarly and more consistently than glyphosate EPOST. Regardless of PRE treatment, sequential glyphosate applications provided at least 98% control of entireleaf and pitted morningglory, whereas glyphosate EPOST controlled at least 64 and 62%, respectively. Glyphosate EPOST and the sequential glyphosate EPOST fb POST systems yielded similarly at all three locations. Net returns were highest at all three locations with the glyphosate sequential system, with similar net returns obtained with glyphosate EPOST and glyphosate plus halosulfuron EPOST at two and one locations, respectively. DA - 2004/// PY - 2004/// DO - 10.1614/WT-03-222R VL - 18 IS - 4 SP - 1049-1057 SN - 1550-2740 KW - diammonium salt KW - isopropylamine salt KW - net returns ER - TY - JOUR TI - Recovery of exotic alleles in semiexotic maize inbreds derived from crosses between Latin American accessions and a temperate line AU - Tarter, JA AU - Goodman, MM AU - Holland, JB T2 - THEORETICAL AND APPLIED GENETICS DA - 2004/8// PY - 2004/8// DO - 10.1007/s00122-004-1660-6 VL - 109 IS - 3 SP - 609-617 SN - 0040-5752 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-4344701300&partnerID=MN8TOARS ER - TY - JOUR TI - Physiological basis for cotton tolerance to flumioxazin applied postemergence directed AU - Price, AJ AU - Pline, WA AU - Cranmer, , JR AU - Danehower, D T2 - WEED SCIENCE AB - Previous research has shown that flumioxazin, a herbicide being developed as a postemergence-directed spray (PDS) in cotton, has the potential to injure cotton less than 30 cm tall if the herbicide contacts green stem tissue by rain splash or misapplication. In response to this concern, five-leaf cotton plants with chlorophyllous stems and older cotton, 16-leaf cotton plants, with bark on the lower stem were treated with a PDS containing flumioxazin plus crop oil concentrate (COC) or nonionic surfactant (NIS). Stems of treated plants and untreated plants at the respective growth stage were cross-sectioned and then magnified and photographed using bright-field microscopy techniques. More visible injury consisting of necrosis and desiccation was evident in younger cotton. Also, there was a decrease in treated-stem diameter and an increase in visible injury with COC compared with NIS in younger cotton. The effects of plant growth stage and harvest time on absorption, translocation, and metabolism of 14 C-flumioxazin in cotton were also investigated. Total 14 C absorbed at 72 h after treatment (HAT) was 77, 76, and 94% of applied at 4-, 8-, and 12-leaf growth stages, respectively. Cotton at the 12-leaf stage absorbed more 14 C within 48 HAT than was absorbed by four- or eight-leaf cotton by 72 HAT. A majority (31 to 57%) of applied 14 C remained in the treated stem for all growth stages and harvest times. Treated cotton stems at all growth stages and harvest times contained higher concentrations (Bq g −1 ) of 14 C than any other tissues. Flumioxazin metabolites made up less than 5% of the radioactivity found in the treated stem. Because of the undetectable levels of metabolites in other tissues when flumioxazin was applied PDS, flumioxazin was foliar applied to determine whether flumioxazin transported to the leaves may have been metabolized. In foliar-treated cotton, flumioxazin metabolites in the treated leaf of four-leaf cotton totaled 4% of the recovered 14 C 72 HAT. Flumioxazin metabolites in the treated leaf of 12-leaf cotton totaled 35% of the recovered 14 C 48 HAT. These data suggest that differential absorption, translocation, and metabolism at various growth stages, as well as the development of a bark layer, are the bases for differential tolerances of cotton to flumioxazin applied PDS. DA - 2004/// PY - 2004/// DO - 10.1614/ws-03-038r VL - 52 IS - 1 SP - 1-7 SN - 1550-2759 KW - absorption KW - translocation KW - metabolism ER - TY - JOUR TI - Peanut response to planting pattern, row spacing, and irrigation AU - Lanier, JE AU - Jordan, DL AU - Spears, JF AU - Wells, R AU - Johnson, PD AU - Barnes, JS AU - Hurt, CA AU - Brandenburg, RL AU - Bailey, JE T2 - AGRONOMY JOURNAL AB - Experiments were conducted from 1999 through 2002 in North Carolina to compare interactions of planting pattern, plant population, and irrigation on peanut ( Arachis hypogaea L.) pod yield and market grade characteristics. In additional experiments, pod yield and severity of tomato spotted wilt tospovirus associated with the cultivars NC‐V 11, NC 12C, VA 98R, and Perry were compared in single row (rows spaced 91 cm apart) and standard twin row (two rows spaced 18 cm apart on 91‐cm centers) planting patterns when peanut was dug and vines inverted on two digging dates spaced 10 to 16 d apart. In a third set of experiments, pod yield, market grade characteristics, and severity of tomato spotted wilt tospovirus were compared when the cultivars NC‐V 11 and Perry were planted in single row, standard twin row, and narrow twin row (two rows spaced 18 cm apart on 46‐cm centers) planting patterns. Peanut pod yield was higher in standard twin row planting patterns than when grown in single row planting patterns in some but not all experiments. Planting peanut in the narrow twin row pattern did not increase peanut pod yield over the standard twin row planting pattern. Less tomato spotted wilt was observed in standard or narrow twin row planting patterns compared with single row planting patterns. Planting peanut in single rows spaced 46 cm apart did not improve yield over peanut planted in single rows spaced 91 cm apart or the standard twin row planting pattern, regardless of irrigation treatment. DA - 2004/// PY - 2004/// DO - 10.2134/agronj2004.1066 VL - 96 IS - 4 SP - 1066-1072 SN - 1435-0645 ER - TY - JOUR TI - Members of a new group of chitinase-like genes are expressed preferentially in cotton cells with secondary walls AU - Zhang, DS AU - Hrmova, M AU - Wan, CH AU - Wu, CF AU - Balzen, J AU - Cai, W AU - Wang, J AU - Densmore, LD AU - Fincher, GB AU - Zhang, H AU - Haigler, CH T2 - PLANT MOLECULAR BIOLOGY DA - 2004/2// PY - 2004/2// DO - 10.1023/B:PLAN.0000036369.55253.dd VL - 54 IS - 3 SP - 353-372 SN - 1573-5028 KW - cellulose KW - chitin binding KW - cotton fiber KW - molecular modeling KW - promoter activity KW - secondary cell wall ER - TY - JOUR TI - Fermentation of eastern gamagrass (Tripsacum dactyloides [L.] L.) by mixed cultures of ruminal microorganisms with or without supplemental corn AU - Eun, J. S. AU - Fellner, V. AU - Burns, J. C. AU - Gumpertz, M. L. T2 - Journal of Animal Science AB - Five dual-flow fermentors (700 mL) were used to determine the effects of eastern gamagrass (Tripsacum dactyloides [L.] L.) diets on microbial metabolism by mixed rumen cultures. Fermentors were incubated with filtered ruminal contents and allowed to adapt for 4 d to diets followed by 3 d of sample collection. Five dietary treatments were tested: 1) gamagrass hay (GH) + no corn (GHNC), 2) gama grass silage (GS) + no corn (GSNC), 3) GS + low corn (GSLC), 4) GS + medium corn (GSMC); and 5) GS + high corn (GSHC). The experiment was conducted as a randomized complete block design with five treatments and three replications. Total VFA concentrations were not affected by diets. Corn addition linearly decreased (P < 0.001) molar proportion of acetate. In contrast, molar proportion of propionate was reduced in GSLC (cubic effect, P < 0.001) but remained similar across other diets. Corn supplementation linearly increased molar proportion of butyrate (P < 0.001). The acetate + butyrate-to-propionate ratio was highest in cultures offered GSLC (cubic effect, P < 0.001) but similar across other diets. Feeding GSNC resulted in a higher ruminal pH compared with GHNC (P < 0.03). Increasing the level of corn supplementation in GS linearly decreased culture pH (P < 0.001). All diets resulted in similar methane production, with the exception of GSMC, which lowered methane output (quadratic effect, P < 0.004). Total substrate fermented to VFA and gas tended to be greater with GHNC than with GSNC (P < 0.06) and linearly increased with the addition of corn (P < 0.004). Neutral detergent fiber digestibility was similar between GH and GS and was not affected by supplemental corn. Microbial N flow increased in cultures offered GSHC (quadratic effect, P < 0.02). Corn supplementation at the medium and high level linearly decreased C 18:0 (P < 0.02) and increased trans-C18:1 (P < 0.004). Including corn at the high level with GS did not have a detrimental effect on fermentation in dual-flow fermentors. DA - 2004/// PY - 2004/// DO - 10.2527/2004.821170x VL - 82 IS - 1 SP - 170-178 ER - TY - JOUR TI - Evaluating the potential for site-specific herbicide application in soybean AU - Wilkerson, GG AU - Price, AJ AU - Bennett, AC AU - Krueger, DW AU - Roberson, GT AU - Robinson, BL T2 - WEED TECHNOLOGY AB - Field experiments were conducted on two North Carolina research stations in 1999, 2000, and 2001; on-farm in Lenoir, Wayne, and Wilson counties, NC, in 2002; and on-farm in Port Royal, VA, in 2000, 2001, and 2002 to evaluate possible gains from site-specific herbicide applications at these locations. Fields were scouted for weed populations using custom software on a handheld computer linked to a Global Positioning System. Scouts generated field-specific sampling grids and recorded weed density information for each grid cell. The decision aid HADSS™ (Herbicide Application Decision Support System) was used to estimate expected net return and yield loss remaining after treatment in each sample grid of every field under differing assumptions of weed size and soil moisture conditions, assuming the field was planted with either conventional or glyphosate-resistant (GR) soybean. The optimal whole-field treatment (that treatment with the highest expected net return summed across all grid cells within a field) resulted in average theoretical net returns of $79/ha (U.S. dollars) and $139/ha for conventional and GR soybean, respectively. When the most economical treatment for each grid cell was used in site-specific weed management, theoretical net returns increased by $13/ha (conventional) and $4.50/ha (GR), and expected yield loss after treatment was reduced by 10.5 and 4%, respectively, compared with the whole-field optimal treatment. When the most effective treatment for each grid cell was used in site-specific weed management, theoretical net returns decreased by $18/ha (conventional) and $4/ha (GR), and expected yield loss after treatment was reduced by 27 and 19%, respectively, compared with the whole-field optimal treatment. Site-specific herbicide applications could have reduced the volume of herbicides sprayed by as much as 70% in some situations but increased herbicide amounts in others. On average, the whole-field treatment was optimal in terms of net return for only 35% (conventional) and 57% (GR) of grid cells. DA - 2004/// PY - 2004/// DO - 10.1614/WT-03-258R VL - 18 IS - 4 SP - 1101-1110 SN - 0890-037X KW - computer decision aids KW - economic threshold KW - integrated pest management KW - variable rate herbicide application ER - TY - JOUR TI - Effect of soluble silica on brown patch and dollar spot of creeping bentgrass AU - Uriarte, RF AU - Shew, HD AU - Bowman, DC T2 - JOURNAL OF PLANT NUTRITION AB - Abstract Disease pressure on cool season turfgrasses is very high in the transition zone due to the heat and humidity of prolonged summers. Creeping bentgrass (Agrostis stolonifera L.) is susceptible to both brown patch (Rhizoctonia solani Kuhn) and dollar spot (Sclerotinia homoeocarpa F.T. Bennett) fungi. The objective of this study was to assess the potential of soluble silica for reducing the severity or incidence of disease on creeping bentgrass. Two mature stands of creeping bentgrass, maintained as putting greens, were used. Both greens were constructed to USGA specifications and planted with either “Penncross” or “Cato” and “Crenshaw” blend creeping bentgrass. Plots were treated biweekly with silica at rates of 0, 25, and 50 kg ha−1. Turf quality was unaffected by silica application. Differences in disease incidence between the silica treatments and the control were observed in 1995 but not in 1996. There was no effect of treatment on tissue Si, suggesting that creeping bentgrass may be a Si excluder. Based on these results, silica may provide some degree of protection from dollar spot and brown patch. However, the level of control is unlikely to satisfy expectations for putting green turf quality. DA - 2004/// PY - 2004/// DO - 10.1081/PLN-120027657 VL - 27 IS - 2 SP - 325-339 SN - 1532-4087 KW - turfgrass disease KW - Rhizoctonia solani KW - Sclerotinia homoeocarpa KW - integrated pest management ER - TY - JOUR TI - Effect of soil pH on the pathogenesis of Heterodera glycines and Meloidogyne incognita on Glycine max genotypes AU - Melakeberhan, H AU - Dey, J AU - Baligar, VC AU - Carter, TE T2 - NEMATOLOGY AB - Abstract The effect of soil pH 4.3, 4.6, and 5.9 on the pathogenicity of Heterodera glycines and Meloidogyne incognita on acid soiladapted soybean genotypes (Davis and PI 416937) was investigated in three glasshouse experiments over 28 days after inoculation with 0 or 1000 (Experiments 1 and 2) and 0 or 5000 (Experiment 3) second-stage juveniles. Although nematodes of both species infected both genotypes at all of the soil pH, the numbers decreased with decreasing soil pH. Both genotypes seem to be better hosts for M. incognita than for H. glycines, Davis more so than PI 416937. Both nematodes decreased shoot weight at high inoculum levels, indicating that H. glycines may be more pathogenic than M. incognita. Nematode development after infection of roots was not affected by soil pH or by genotypes. Overall, the results suggest that adaptation of these nematodes should be considered in breeding programmes to develop low pH tolerant soybean cultivars. DA - 2004/// PY - 2004/// DO - 10.1163/1568541042665205 VL - 6 SP - 585-592 SN - 1388-5545 KW - nematode adaptation KW - nematode development KW - pathogenicity KW - soil types ER - TY - JOUR TI - Effect of glyphosate application timings and methods on glyphosate-resistant cotton AU - Viator, RP AU - Jost, PH AU - Senseman, SA AU - Cothren, JT T2 - WEED SCIENCE AB - Under certain conditions, application of glyphosate to glyphosate-resistant (GR) cotton can lead to fruit shedding and yield reductions. Field studies were conducted at the Texas Agricultural Experiment Station using GR cotton, cv. ‘DeltaPine 5690RR’, to determine if application method and timing affect cotton fruit retention. Glyphosate at 1.12 kg ai ha −1 was precisely postdirected (PD), postdirected with 25% foliage coverage (PDFC), or applied over the top (OT) at the 8- or 18-leaf stage after an initial topical application of 1.12 kg ha −1 glyphosate at the four-leaf stage. In one of the years of this study, 8 PD, 18 PDFC, and 18 OT reduced yield. In 1999 and 2000, 8 PDFC and 8 OT applications of glyphosate caused yield loss, mainly due to lower mean boll weight. Glyphosate applied topically at the eight-leaf stage also affected the Position 1 boll retention throughout the plant in both years. Glyphosate contact with leaves and stems should be avoided when applying glyphosate after the four-leaf stage to prevent possible yield loss. DA - 2004/// PY - 2004/// DO - 10.1614/P2002-025 VL - 52 IS - 1 SP - 147-151 SN - 0043-1745 KW - herbicide resistant KW - transgenic crops ER - TY - JOUR TI - Disease management in overhead sprinkler and subsurface drip irrigation systems for peanut AU - Lanier, JE AU - Jordan, DL AU - Barnes, JS AU - Matthews, J AU - Grabow, GL AU - Griffin, WJ AU - Bailey, JE AU - Johnson, PD AU - Spears, JF AU - Wells, R T2 - AGRONOMY JOURNAL AB - Experiments were conducted during 2001 and 2002 at one location in North Carolina to compare development of early leaf spot ( Cercospora arachidicola Hori), pod yield, and market grade characteristics when peanut ( Arachis hypogea L.) was grown under overhead sprinkler irrigation (OSI) and subsurface drip irrigation (SDI) and fungicides were not applied or applied biweekly or based on weather advisories. Incidence of early leaf spot was lower when peanut was grown under SDI compared with OSI when fungicides were not applied. Fewer fungicide applications were needed when applications were based on weather advisories rather than when applied biweekly. There was no difference in early leaf spot control or leaf defoliation resulting from disease when fungicides were applied regardless of irrigation system or fungicide application approach. Pod yield was higher in 2001 under SDI compared with OSI when fungicides were not applied; yield was similar in 2002. Disease severity was much higher in 2001 than in 2002 and most likely explains differences in pod yield between years. No difference in yield was noted when fungicides were applied, regardless of irrigation system. The percentage of extra large kernels (%ELK) was lower in 1 of 2 yr under SDI compared with OSI. There were no differences in percentages of fancy pods (%FP), sound splits (%SS), and other kernels (%OK) among irrigation systems and fungicide programs. In a separate experiment where fungicides were applied biweekly, pod yield, %FP, and %ELK were similar under SDI and OSI but greater than nonirrigated peanut. The %OK was lower when peanut was irrigated. DA - 2004/// PY - 2004/// DO - 10.2134/agronj2004.1058 VL - 96 IS - 4 SP - 1058-1065 SN - 1435-0645 ER - TY - JOUR TI - Cool temperature hinders flux from glucose to sucrose during cellulose synthesis in secondary wall stage cotton fibers AU - Martin, LK AU - Haigler, CH T2 - CELLULOSE DA - 2004/// PY - 2004/// DO - 10.1023/B:CELL.0000046420.10403.15 VL - 11 IS - 3-4 SP - 339-349 SN - 1572-882X KW - cellulose synthesis KW - cool temperature stress KW - cotton fiber KW - fructose KW - glucose KW - Gossypium hirsutum KW - in vitro culture KW - metabolic flux KW - secondary wall KW - sucrose synthesis ER - TY - JOUR TI - Weed management in cotton with CGA-362622, fluometuron, and pyrithiobac AU - Burke, IC AU - Wilcut, JW T2 - WEED TECHNOLOGY AB - An experiment was conducted at five locations in North Carolina during 2000 and 2001 to evaluate weed control, crop injury, and cotton yield. Weed management systems included different combinations of pyrithiobac preemergence (PRE), fluometuron PRE, CGA-362622 postemergence (POST), pyrithiobac POST, and monosodium salt of methylarsonic acid (MSMA) plus prometryn applied late POST-directed (LAYBY). At Goldsboro in 2000, cotton was injured 74 to 78% by CGA-362622 POST when evaluated 4 to 7 d after treatment (DAT). Injury at Clayton, Goldsboro, and Lewiston in 2001 and Rocky Mount in 2000 was less than 16% 4 to 7 DAT with the same treatment and was not apparent by 62 DAT. CGA-362622 controlled common lambsquarters, common ragweed, Palmer amaranth, sicklepod, smooth pigweed, and Ipomoea species including entireleaf, ivyleaf, and pitted morningglory, and the addition of pyrithiobac to the herbicide system, either PRE or POST, increased control of Amaranthus species, jimsonweed, and prickly sida. CGA-362622 did not control jimsonweed or prickly sida. Fluometuron PRE, pyrithiobac PRE, and MSMA plus prometryn LAYBY were beneficial for increasing weed control and cotton lint yields. Prometryn plus MSMA LAYBY increased control of common ragweed, entireleaf morningglory, jimsonweed, pitted morningglory, and smooth pigweed and provided higher cotton yields than similar systems without a LAYBY. The greatest weed control and greatest cotton lint yields required complete weed management systems that included a combination of PRE, POST, and LAYBY treatments. DA - 2004/// PY - 2004/// DO - 10.1614/WT-03-035R VL - 18 IS - 2 SP - 268-276 SN - 1550-2740 KW - crop injury KW - crop yield ER - TY - JOUR TI - Weed efficacy evaluations for bromoxynil, glufosinate, glyphosate, pyrithiobac, and sulfosate AU - Corbett, JL AU - Askew, SD AU - Thomas, WE AU - Wilcut, JW T2 - WEED TECHNOLOGY AB - Thirteen field trials were conducted in 1999 and 2000 to evaluate postemergence (POST) weed control with single applications of bromoxynil at 420 or 560 g ai/ha, glufosinate at 291 or 409 g ai/ha, glyphosate at 1,120 g ai/ha, pyrithiobac at 36 or 72 g ai/ha, or sulfosate at 1,120 g ai/ha. Additional treatments evaluated included two applications with glufosinate at both rates in all possible combinations, two applications of glyphosate, and two applications of sulfosate. Weeds were 2 to 5 cm or 8 to 10 cm tall for annual grass and broadleaf weeds whereas yellow nutsedge and glyphosate-resistant corn were 8 to 10 cm tall. All herbicide treatments controlled 2- to 5-cm common cocklebur, Florida beggarweed, jimsonweed, ladysthumb smartweed, Pennsylvania smartweed, pitted morningglory, prickly sida, redroot pigweed, smooth pigweed, and velvetleaf at least 90%. All herbicide treatments except pyrithiobac at either rate controlled 2- to 5-cm common lambsquarters, common ragweed, and tall morningglory at least 90%; pyrithiobac at the lower rate was the only treatment that failed to control entireleaf and ivyleaf morningglory at least 90%. Bromoxynil and pyrithiobac at either rate controlled 2- to 5-cm sicklepod 33 to 68% whereas glufosinate, glyphosate, and sulfostate controlled ≥99%. Glyphosate and sulfosate applied once or twice controlled hemp sesbania less than 70% and volunteer peanut less than 80%. Bromoxynil and pyrithiobac were the least effective treatments for control of annual grass species and bromoxynil controlled Palmer amaranth less than 80%. Glufosinate controlled broadleaf signalgrass, fall panicum, giant foxtail, green foxtail, large crabgrass, yellow foxtail, seedling johnsongrass, Texas panicum, and glyphosate-resistant corn at least 90% but controlled goosegrass less than 60%. Glyphosate and sulfosate controlled all grass species except glyphosate-resistant corn at least 90%. In greenhouse research, goosegrass could be controlled with glufosinate POST plus a late POST-directed treatment of prometryn plus monosodium salt of methylarsonic acid. DA - 2004/// PY - 2004/// DO - 10.1614/WT-03-139R VL - 18 IS - 2 SP - 443-453 SN - 1550-2740 KW - herbicide-resistant crops KW - nonselective herbicides KW - AMACH KW - AMAPA KW - AMARE KW - AMBEL KW - ARAHY KW - BRAPP KW - CASOB KW - CHEAL KW - CYPES KW - DATST KW - DEDTO KW - DIGSA KW - ELEIN KW - IPOHE KW - IPOHG KW - IPOLA KW - PANDI KW - PANTE KW - PHBPU KW - POLPE KW - POLPY KW - SEBEX KW - SETFA KW - SETLU KW - SETVI KW - SIDSP KW - SORHA KW - XANST KW - ZEAMA ER - TY - JOUR TI - Tropical spiderwort (Commelina benghalensis) control in glyphosate-resistant cotton AU - Culpepper, AS AU - Flanders, JT AU - York, AC AU - Webster, TM T2 - WEED TECHNOLOGY AB - Tropical spiderwort has recently become the most troublesome weed in Georgia cotton. Most of Georgia's cotton is glyphosate resistant (GR), and glyphosate is only marginally effective on tropical spiderwort. An experiment was conducted at four locations to determine tropical spiderwort control in GR cotton by 27 herbicide systems. Treatments consisted of three early-postemergence over-the-top (POT) herbicide options and nine late–postemergence-directed (LPD) options arranged factorially. Glyphosate POT controlled tropical spiderwort only 53% 21 d after treatment (DAT). Glyphosate plus pyrithiobac or S-metolachlor controlled tropical spiderwort 60 and 80%, respectively. Pyrithiobac improved control of emerged spiderwort, whereas S-metolachlor provided residual control. Pooled over POT treatments, glyphosate LPD controlled tropical spiderwort 70% 21 DAT. Dimethipin mixed with glyphosate did not improve control. Carfentrazone, diuron, or flumioxazin mixed with glyphosate LPD improved control 9 to 15%. MSMA and MSMA plus flumioxazin were 8 and 19% more effective than glyphosate LPD. At time of cotton harvest, systems without residual herbicides at LPD controlled tropical spiderwort 42 to 45% compared with 64 to 76% with LPD treatments that included diuron or flumioxazin. DA - 2004/// PY - 2004/// DO - 10.1614/WT-03-175R VL - 18 IS - 2 SP - 432-436 SN - 1550-2740 KW - invasive weed KW - noxious weed KW - weed shift ER - TY - JOUR TI - Tolerance of six soft red winter wheat cultivars to AE F130060 00 plus AE F115008 00 AU - Crooks, HL AU - York, AC AU - Jordan, DL T2 - WEED TECHNOLOGY AB - Tolerance of six soft red winter wheat cultivars to AE F130060 00 plus AE F115008 00 applied at 12.5 plus 2.5 g ai/ha and 25 plus 5 g ai/ha, respectively, at the two- to three-tiller stage was examined under weed-free conditions at four locations over 2 yr. Visible injury averaged 5 and 15% 3 wk after treatment (WAT) in years 1 and 2, respectively. Injury was 2% or less 10 WAT. No differences among cultivars were noted for visible injury, and AE F130060 00 plus AE F115008 00 did not reduce grain yield in year 1. In year 2, averaged over herbicide rates, grain yields of the cultivars ‘Coker 9663’, ‘Pioneer 2580’, ‘Coker 9704’, ‘Pioneer 2684’, ‘FFR 555’, and ‘Jackson’ were reduced 3, 5, 6, 8, 10, and 16%, respectively. The yield reduction for Jackson was different from those for the other cultivars. Yield reduction was attributed to reduced numbers of kernels per spike. DA - 2004/// PY - 2004/// DO - 10.1614/WT-03-031R VL - 18 IS - 2 SP - 252-257 SN - 1550-2740 KW - cultivar response KW - yield components ER - TY - JOUR TI - Sulfentrazone persistence in southern soils: Bioavailable concentration and effect on a rotational cotton crop AU - Main, CL AU - Mueller, TC AU - Hayes, RM AU - Wilcut, JW AU - Peeper, TF AU - Talbert, RE AU - Witt, WW T2 - WEED TECHNOLOGY AB - Field studies were conducted from 1998 to 2000 in Tennessee, North Carolina, Arkansas, and Oklahoma to determine the effects of sulfentrazone carryover to a cotton rotational crop from sulfentrazone applied the previous year. Sulfentrazone applied the previous year at 400 g/ha caused no yield loss in Tennessee, >30% yield reduction in Oklahoma, and 20% yield loss in Arkansas and North Carolina. In most experiments in this study, visual evaluations of injury closely correlated with final cotton lint yield ( r 2 =0.84). DA - 2004/// PY - 2004/// DO - 10.1614/WT-03-091R1 VL - 18 IS - 2 SP - 346-352 SN - 1550-2740 KW - bioassay KW - herbicide carryover KW - PROTOX inhibitor KW - rotational crops ER - TY - JOUR TI - Response of ultra-narrow and conventional spaced cotton to variable nitrogen rates AU - Rinehardt, JM AU - Edmisten, KL AU - Wells, R AU - Faircloth, JC T2 - JOURNAL OF PLANT NUTRITION AB - Abstract Insufficient nitrogen (N) uptake in cotton (Gossypium hirsutum L.) has been shown to delay maturity and decrease lint yields, while excessive amounts will cause a host of disadvantages, ranging from increased insect damage to defoliation difficulties. Proper nitrogen fertilization rates are therefore essential to maximizing lint production while minimizing input costs. This test was designed to determine if ultra–narrow row cotton (UNRC) has similar nitrogen requirements as conventional row cotton (CRC). Two sites, one in peanuts and the other fallow the previous growing season, and four nitrogen rates (45, 67, 90, and 112 kg N ha−1) were used to compare soil fertility and nitrogen effects on petiole nitrate concentrations, lint yields, and ginning percentages. Although petiole nitrate concentrations between early and peak bloom were lower in ultra–narrow row cotton with 45 and 67 kg N ha−1, there was no correlation between petiole nitrate concentrations and lint yield. Conventional spacing receiving 67 kg N ha−1 had the highest lint production at both locations, while application of 90 kg N ha−1 produced the highest yields in UNRC at both locations. Ultra–narrow row cotton produced numerically higher yields than conventional row at all nitrogen rates at the location without a previous legume crop, but no significant trend was observed. Ultra–narrow row cotton lint percentages were significantly lower than conventional spacing, independent of nitrogen application rate. DA - 2004/// PY - 2004/// DO - 10.1081/PLN-120030379 VL - 27 IS - 4 SP - 743-755 SN - 1532-4087 ER - TY - JOUR TI - Registration of NC113 soybean mapping population AU - Narvel, JM AU - Carter, TE AU - Jakkula, LR AU - Alvernaz, J AU - Bailey, MA AU - Mian, MAR AU - Lee, SH AU - Lee, GJ AU - Boerma, HR T2 - CROP SCIENCE AB - Crop ScienceVolume 44, Issue 2 p. 704-706 Registration of Mapping Population Registration of NC113 Soybean Mapping Population J.M. Narvel, J.M. Narvel Dep. of Crop and Soil Sciences, 3111 Miller Plant Sciences Bldg, Univ. of Georgia, Athens, GA, 30602-7272Search for more papers by this authorT.E. Carter, Corresponding Author T.E. Carter [email protected] USDA-ARS, North Carolina State Univ., 3217 Ligon St., Raleigh, NC, 27695-7631Corresponding author ([email protected])Search for more papers by this authorL.R. Jakkula, L.R. Jakkula Dep. of Crop and Soil Sciences, 3111 Miller Plant Sciences Bldg, Univ. of Georgia, Athens, GA, 30602-7272Search for more papers by this authorJ. Alvernaz, J. Alvernaz Dep. of Crop and Soil Sciences, 3111 Miller Plant Sciences Bldg, Univ. of Georgia, Athens, GA, 30602-7272Search for more papers by this authorM.A. Bailey, M.A. Bailey Pioneer Hi-Bred International, Inc., 7300 NW 62nd Avenue, P.O. Box 1004, Johnston, IA, 50131-1004Search for more papers by this authorM.A.R. Mian, M.A.R. Mian Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK, 73402Search for more papers by this authorS.H. Lee, S.H. Lee Dep. of Crop and Soil Sciences, 3111 Miller Plant Sciences Bldg, Univ. of Georgia, Athens, GA, 30602-7272 School of Plant Science, Seoul National University, Suwon, 441-744 KoreaSearch for more papers by this authorG.J. Lee, G.J. Lee Dep. of Crop and Soil Sciences, 3111 Miller Plant Sciences Bldg, Univ. of Georgia, Athens, GA, 30602-7272 School of Plant Science, Seoul National University, Suwon, 441-744 KoreaSearch for more papers by this authorH.R. Boerma, H.R. Boerma Dep. of Crop and Soil Sciences, 3111 Miller Plant Sciences Bldg, Univ. of Georgia, Athens, GA, 30602-7272Search for more papers by this author J.M. Narvel, J.M. Narvel Dep. of Crop and Soil Sciences, 3111 Miller Plant Sciences Bldg, Univ. of Georgia, Athens, GA, 30602-7272Search for more papers by this authorT.E. Carter, Corresponding Author T.E. Carter [email protected] USDA-ARS, North Carolina State Univ., 3217 Ligon St., Raleigh, NC, 27695-7631Corresponding author ([email protected])Search for more papers by this authorL.R. Jakkula, L.R. Jakkula Dep. of Crop and Soil Sciences, 3111 Miller Plant Sciences Bldg, Univ. of Georgia, Athens, GA, 30602-7272Search for more papers by this authorJ. Alvernaz, J. Alvernaz Dep. of Crop and Soil Sciences, 3111 Miller Plant Sciences Bldg, Univ. of Georgia, Athens, GA, 30602-7272Search for more papers by this authorM.A. Bailey, M.A. Bailey Pioneer Hi-Bred International, Inc., 7300 NW 62nd Avenue, P.O. Box 1004, Johnston, IA, 50131-1004Search for more papers by this authorM.A.R. Mian, M.A.R. Mian Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK, 73402Search for more papers by this authorS.H. Lee, S.H. Lee Dep. of Crop and Soil Sciences, 3111 Miller Plant Sciences Bldg, Univ. of Georgia, Athens, GA, 30602-7272 School of Plant Science, Seoul National University, Suwon, 441-744 KoreaSearch for more papers by this authorG.J. Lee, G.J. Lee Dep. of Crop and Soil Sciences, 3111 Miller Plant Sciences Bldg, Univ. of Georgia, Athens, GA, 30602-7272 School of Plant Science, Seoul National University, Suwon, 441-744 KoreaSearch for more papers by this authorH.R. Boerma, H.R. Boerma Dep. of Crop and Soil Sciences, 3111 Miller Plant Sciences Bldg, Univ. of Georgia, Athens, GA, 30602-7272Search for more papers by this author First published: 01 March 2004 https://doi.org/10.2135/cropsci2004.7040Citations: 7 Registration by CSSA. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume44, Issue2March–April 2004Pages 704-706 RelatedInformation DA - 2004/// PY - 2004/// DO - 10.2135/cropsci2004.7040 VL - 44 IS - 2 SP - 704-706 SN - 1435-0653 ER - TY - JOUR TI - Glufosinate does not affect floral morphology and pollen viability in glufosinate-resistant cotton AU - Thomas, WE AU - Pline, WA AU - Wilcut, JW AU - Edmisten, KL AU - Wells, R AU - Viator, RR AU - Paulsgrove, MD T2 - WEED TECHNOLOGY AB - Studies were conducted to determine whether glufosinate treatments to glufosinate-resistant cotton caused changes in floral morphology, pollen viability, and seed set. Four glufosinate treatments were included: (1) glufosinate applied postemergence over the top (POST) at the four-leaf stage, (2) glufosinate applied POST at the eight-leaf stage, (3) the first two treatments sequentially, and (4) a POST application at the four-leaf stage followed by (fb) a postemergence-directed stem application (PDS) at the eight-leaf stage. Glufosinate was consistently applied at 0.49 kg ai/ha. A nontreated control was included. Glufosinate treatments did not affect stigma height, length of the staminal column, or pollen viability. However, the distance from the top anther to the tip of the stigma was less in plants treated with an eight-leaf POST treatment than in nontreated plants, although this difference is not likely to influence pollen deposition because in both cases anthers reached above the stigma tip. Plants receiving four-leaf POST fb eight-leaf PDS treatment with glufosinate had eight seeds per boll less than nontreated plants; however, the more rigorous four-leaf POST fb eight-leaf POST treatment did not differ from the nontreated in seeds per boll. DA - 2004/// PY - 2004/// DO - 10.1614/WT-03-032R1 VL - 18 IS - 2 SP - 258-262 SN - 1550-2740 KW - glyphosate KW - herbicide-resistant crops KW - transgenic crops ER - TY - JOUR TI - Flumioxazin preplant or post-directed application timing followed by irrigation at emergence or after post-directed spray treatment does not influence cotton yield AU - Price, AJ AU - Wilcut, JW AU - Cranmer, , JR T2 - WEED TECHNOLOGY AB - Three experiments were conducted in Lewiston, NC, from 1999 through 2002 to evaluate the influence of various application timings of flumioxazin preplant (PP) and postemergence-directed spray (PDS) on cotton injury. In experiment 1, flumioxazin was evaluated in a reduced-tillage system at 71, 105, or 140 g ai/ha in mixture with glyphosate, applied at 28, 14, or 7 d before planting (DBP), followed by irrigation at cotton emergence. Flumioxazin applied PP at any rate and irrigated at emergence injured cotton less than 7% at 2 wk after emergence (WAE) and less than 6% 5 WAE. In experiment 2, flumioxazin was evaluated in a conventional-tillage system at 71 or 105 g/ha as a PDS treatment applied to dry soil, wet soil, and dry soil irrigated immediately after application when cotton was 20 to 30 cm height. Cotton treated with flumioxazin PDS at either rate applied to dry soil, wet soil, or dry soil followed immediately by irrigation was not injured. In the third experiment, flumioxazin at 71 g/ha alone or in mixture with glyphosate at 1.12 g/ha was applied at 30, 21, 14, and 0 DBP in a conventional-tillage system. Flumioxazin applied alone or in mixture with glyphosate applied at any time did not injure cotton. In all experiments, cotton lint yields were not influenced by herbicide treatment. DA - 2004/// PY - 2004/// DO - 10.1614/WT-03-068R VL - 18 IS - 2 SP - 310-314 SN - 1550-2740 KW - burndown treatment KW - LAYBY treatment ER - TY - JOUR TI - Calculating pesticide sorption coefficients (K-d) using selected soil properties AU - Weber, JB AU - Wilkerson, GG AU - Reinhardt, CF T2 - CHEMOSPHERE AB - Pesticide soil/solution distribution coefficients ( Kd values), commonly referred to as pesticide soil sorption values, are utilized in computer and decision aid models to predict soil mobility of the compounds. The values are specific for a given chemical in a given soil sample, normally taken from surface soil, a selected soil horizon, or at a specific soil depth, and are normally related to selected soil properties. Pesticide databases provide Kd values for each chemical, but the values vary widely depending on the soil sample on which the chemicals were tested. We have correlated Kd values reported in the literature with the reported soil properties for an assortment of pesticides in an attempt to improve the accuracy of a Kd value for a specific chemical in a soil with known soil properties. Mathematical equations were developed from regression equations for the related properties. Soil properties that were correlated included organic matter content, clay mineral content, and/or soil pH, depending on the chemical properties of the pesticide. Pesticide families for which Kd equations were developed for 57 pesticides include the following: Carboxy acid, amino sulfonyl acid, hydroxy acid, weakly basic compounds and nonionizable amide/anilide, carbamate, dinitroaniline, organochlorine, organophosphate, and phenylurea compounds. Mean Kd values for 32 additional pesticides, many of which had Kd values that were correlated with specific soil properties but for which no significant Kd equations could be developed are also included. DA - 2004/4// PY - 2004/4// DO - 10.1016/j.chemosphere.2003.10.049 VL - 55 IS - 2 SP - 157-166 SN - 0045-6535 KW - K-d value KW - pesticide sorption KW - pesticide retention KW - pesticide binding KW - leaching potential ER - TY - JOUR TI - Wheat (Triticuin aestivum) tolerance and Italian ryegrass (Lolium multiflorum) control with AE f130060 00 plus AE f115008 00 applied in nitrogen AU - Crooks, HL AU - York, AC AU - Jordan, DL T2 - WEED TECHNOLOGY AB - Soft red winter wheat tolerance to and Italian ryegrass control by a mixture of AE F130060 00 plus AE F115008 00 plus safener applied in water or urea ammonium nitrate (UAN) were evaluated in separate experiments. In the tolerance experiment, wheat responded similarly to AE F130060 00 plus AE F115008 00 at 12.5 plus 2.5 and 25 plus 5 g ai/ha, respectively, applied in water. The herbicides plus nonionic surfactant (NIS) applied in water injured weed-free, five- to seven-tiller wheat 3% or less and did not affect yield. Greater injury occurred with application in UAN, and yield was reduced 11% as result of fewer kernels per spike. NIS added to the herbicides in UAN increased weed-free wheat injury but had no effect on yield. AE F130060 00 plus AE F115008 00 controlled both diclofop-susceptible and -resistant Italian ryegrass. Greater control was obtained with application in UAN as compared with application in water, and NIS increased control. Yield of Italian ryegrass–infested wheat treated with herbicides plus NIS in UAN was similar to or greater than yield when herbicides plus NIS were applied in water.Nomenclature: AEF 115008 00 (proposed name iodosulfuron-methyl-sodium), 4-iodo-2-[[[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]carbonyl]amino]sulfonyl]benzoic acid methyl ester; AE F130060 00 (proposed name mesosulfuron-methyl), methyl 2-[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]-4-[[(methylsulfonyl)amino]methyl] benzoate; Italian ryegrass, Lolium multiflorum Lam. Marshall #3 LOLMU; wheat, Triticum aestivum L. ‘Coker 9704’.Additional index words: Herbicide carriers, surfactant rates, yield components, LOLMU.Abbreviations: GS, Feekes growth stage; NIS, nonionic surfactant; UAN, urea ammonium nitrate; WAT, weeks after treatment. DA - 2004/// PY - 2004/// DO - 10.1614/WT-03-029R VL - 18 IS - 1 SP - 93-99 SN - 1550-2740 KW - herbicide carriers KW - surfactant rates KW - yield components KW - LOLMU ER - TY - JOUR TI - Tropic croton interference in peanut AU - Thomas, WE AU - Askew, SD AU - Wilcut, JW T2 - WEED TECHNOLOGY AB - Studies were conducted to evaluate density-dependent effects of tropic croton on weed and peanut growth and peanut yield. Tropic croton remained taller than peanut throughout the growing season, yet tropic croton density did not affect peanut or tropic croton heights. Tropic croton biomass per plant decreased linearly with increasing plant density. Peanut pod weight decreased linearly 4.7 kg/ha with each gram of increase in tropic croton biomass per meter of crop row. The rectangular hyperbola model was used to describe effects of tropic croton density on percent peanut yield loss. Estimated coefficients for a (maximum yield loss) and i (yield loss per unit density as density approaches zero) were 81 and 26 in 1988, 41 and 33 in 1989, and 33 and 61 in 1998, respectively. Although a and i values varied between years, yield loss predictions were stable between years at weed densities below two plants per meter of crop row. Even though the results show that tropic croton is less competitive than many broadleaf weeds in peanut, it has potential to substantially reduce yields and subsequently reduce economic return.Nomenclature: Tropic croton, Croton glandulosus var. septentrionalis Muell.-Arg. #3 CVNGS; peanut, Arachis hypogaea L. ‘NC 10C’, ‘Florigiant’.Additional index words: Competition, economic threshold, models, plant height, weed biomass, weed density.Abbreviations: PRE, preemergence. DA - 2004/// PY - 2004/// DO - 10.1614/WT-03-018R VL - 18 IS - 1 SP - 119-123 SN - 1550-2740 KW - competition KW - economic threshold KW - models KW - plant height KW - weed biomass KW - weed density ER - TY - JOUR TI - Genetics of postzygotic isolation in eucalyptus: Whole-genome analysis of barriers to introgression in a wide interspecific cross of Eucalyptus grandis and E-globulus AU - Myburg, AA AU - Vogl, C AU - Griffin, AR AU - Sederoff, RR AU - Whetten, RW T2 - GENETICS AB - The genetic architecture of hybrid fitness characters can provide valuable insights into the nature and evolution of postzygotic reproductive barriers in diverged species. We determined the genome-wide distribution of barriers to introgression in an F(1) hybrid of two Eucalyptus tree species, Eucalyptus grandis (W. Hill ex Maiden.) and E. globulus (Labill.). Two interspecific backcross families (N = 186) were used to construct comparative, single-tree, genetic linkage maps of an F(1) hybrid individual and two backcross parents. A total of 1354 testcross AFLP marker loci were evaluated in the three parental maps and a substantial proportion (27.7% average) exhibited transmission ratio distortion (alpha = 0.05). The distorted markers were located in distinct regions of the parental maps and marker alleles within each region were all biased toward either of the two parental species. We used a Bayesian approach to estimate the position and effect of transmission ratio distorting loci (TRDLs) in the distorted regions of each parental linkage map. The relative viability of TRDL alleles ranged from 0.20 to 0.72. Contrary to expectation, heterospecific (donor) alleles of TRDLs were favored as often as recurrent alleles in both backcrosses, suggesting that positive and negative heterospecific interactions affect introgression rates in this wide interspecific pedigree. DA - 2004/3// PY - 2004/3// DO - 10.1534/genetics.166.3.1405 VL - 166 IS - 3 SP - 1405-1418 SN - 0016-6731 ER - TY - JOUR TI - Foliar vs. soil exposure of green kyllinga (Kyllinga brevifolia) and false-green kyllinga (Kyllinga gracillima) to postemergence treatments of CGA-362622, halosulfuron, imazaquin, and MSMA AU - McElroy, JS AU - Yelverton, FH AU - Gannon, TW AU - Wilcut, JW T2 - WEED TECHNOLOGY AB - Greenhouse studies were conducted to evaluate shoot number, shoot weight, rhizome weight, and root weight reduction of green and false-green kyllinga at three placement levels (soil applied, foliar applied, and soil foliar applied) and five herbicide treatments (CGA-362622, halosulfuron, imazaquin, MSMA, and imazaquin MSMA). Averaged over herbicide and placement level, false-green kyllinga shoot number 30 d after treatment (DAT) and rhizome weight 60 DAT were reduced more than those of green kyllinga. Furthermore, imazaquin, MSMA, and imazaquin MSMA, averaged across placement levels, as well as CGA-362622 and halosulfuron, both foliar and soil applied, reduced false-green kyllinga shoot number greater than that of green kyllinga 60 DAT. Halosulfuron reduced false-green kyllinga shoot weight greater than that of green kyllinga 60 DAT; however, MSMA reduced green kyllinga greater. In general, foliar- and soil foliar–applied treatments reduced shoot number (30 DAT), rhizome weight, and root weight of both kyllinga species greater than soil-applied treatments, whereas soil foliar–applied treatments were more effective in reducing shoot weight 60 DAT. CGA-362622 and halosulfuron reduced kyllinga species shoot number (30 DAT), false-green kyllinga shoot weight (60 DAT), and root weight of both species greater than all other herbicides. However, CGA-362622 reduced green kyllinga shoot weight (60 DAT) and rhizome weight of both species greater than all other herbicides.Nomenclature: CGA-362622, N-[(4,6-dimethoxy-2-pyrimidinyl)carbamoyl]-3-(2,2,2-trifluroethoxy)- pyridin-2-sulfonamide sodium salt; halosulfuron; imazaquin; MSMA; false-green kyllinga, Kyllinga gracillima L.; green kyllinga, Kyllinga brevifolia Rottb. #3 KYLBR.Additional index words: Foliar absorption, root absorption.Abbreviations: ALS, acetolactate synthase; DAP, days after planting; DAT, days after treatment; NIS, nonionic surfactant; POST, postemergence. DA - 2004/// PY - 2004/// DO - 10.1614/WT-03-072R VL - 18 IS - 1 SP - 145-151 SN - 1550-2740 KW - foliar absorption KW - root absorption ER - TY - JOUR TI - Differential responses of G-protein Arabidopsis thaliana mutants to ozone AU - Booker, FL AU - Burkey, KO AU - Overmyer, K AU - Jones, AM T2 - NEW PHYTOLOGIST AB - • Ground-level ozone (O3) curtails agricultural production in many regions worldwide. However, the etiology of O3 toxicity remains unclear. Activated oxygen species appear to inflict biochemical lesions and propagate defense responses that compound plant injury. Because some plant defense responses involve membrane-delimited GTPases (G proteins), we evaluated the O3 sensitivity of Arabidopsis mutants altered in the heterotrimeric G-protein pathway. • Eight genotypes were treated with a range of O3 concentrations (0, 100, 175 and 250 nmol mol−1) for 13 d in controlled environment chambers. • After treatment with O3, the epinasty typically observed for wild type leaves did not occur in mutant plants lacking the alpha subunit of the G-protein complex (gpa1). O3-induced suppression of leaf chlorophyll levels and leaf mass per unit leaf area were less for gpa1 mutants and were not due to differences in O3 flux. • There was a positive correlation between the lack of a G-protein alpha subunit and decreased O3 sensitivity. Our results suggest that a heterotrimeric G-protein is critically involved in the expression of O3 effects in plants. DA - 2004/6// PY - 2004/6// DO - 10.1111/j.1469-8137.2004.01081.x VL - 162 IS - 3 SP - 633-641 SN - 1469-8137 KW - Arabidopsis KW - stomatal conductance KW - heterotrimeric G-protein KW - ozone KW - signal transduction ER - TY - JOUR TI - Annual grass control in peanut (Arachis hypogaea) with clethodim and imazapic AU - Burke, IC AU - Price, AJ AU - Wilcut, JW AU - Jordan, DL AU - Culpepper, AS AU - Tredaway-Ducar, J T2 - WEED TECHNOLOGY AB - Field experiments were conducted to evaluate possible interactions of clethodim with imazapic applied as mixtures or sequentially for control of broadleaf signalgrass, fall panicum, goosegrass, and large crabgrass. Imazapic at 70 g ai/ha alone controlled grass weeds inconsistently, whereas clethodim at 140 g ai/ha alone controlled the same weeds at least 99%. Imazapic did not affect broadleaf signalgrass control by clethodim. Reduced control of fall panicum, goosegrass, and large crabgrass was observed when clethodim and imazapic were applied in mixture. Antagonism of clethodim occurred when clethodim was applied 1 d before or up to 3 d after application of imazapic (fall panicum and large crabgrass). Antagonism of goosegrass control was noted when imazapic was applied 3 d before or up to 7 d after application of clethodim. In other experiments, large crabgrass and Texas panicum control by clethodim (70 and 140 g/ha) applied alone or with imazapic (70 g/ ha) or bentazon (1.1 kg ai/ha) plus 2,4-DB (0.28 kg ai/ha) either with or without ammonium sulfate (2.8 kg/ha) was evaluated. Texas panicum control by clethodim was reduced by imazapic regardless of the ammonium sulfate rate. However, large crabgrass control by imazapic was not affected in these experiments. Control of both grasses by clethodim was reduced substantially by bentazon plus 2,4-DB, although in some instances ammonium sulfate improved control when in mixture. Ammonium sulfate improved control by clethodim in some instances irrespective of the broadleaf–sedge herbicide treatments.Nomenclature: Bentazon; clethodim; 2,4-DB; imazapic; broadleaf signalgrass, Brachiaria platyphylla (Griseb) Nash #3 BRAPP; fall panicum, Panicum dichotomiflorum L. # PANDI; goosegrass, Eleusine indica L. Gaertn. # ELEIN; large crabgrass, Digitaria sanguinalis L. Scop. # DIGSA; Texas panicum, Panicum texanum Buckl. # PANTE.Additional index words: Ammonium sulfate, antagonism, herbicide compatibility, herbicide interaction, sequential application. DA - 2004/// PY - 2004/// DO - 10.1614/WT-03-026R VL - 18 IS - 1 SP - 88-92 SN - 1550-2740 KW - ammonium sulfate KW - antagonism KW - herbicide compatibility KW - herbicide interaction KW - sequential application ER - TY - JOUR TI - An auxin-inducible gene from loblolly pine (Pinus taeda L.) is differentially expressed in mature and juvenile-phase shoots and encodes a putative transmembrane protein AU - Busov, VB AU - Johannes, E AU - Whetten, RW AU - Sederoff, RR AU - Spiker, SL AU - Lanz-Garcia, C AU - Goldfarb, B T2 - PLANTA DA - 2004/4// PY - 2004/4// DO - 10.1007/s00425-003-1175-4 VL - 218 IS - 6 SP - 916-927 SN - 1432-2048 KW - adventitious root formation KW - auxin KW - gene expression (5NG4) KW - maturation KW - nodulin KW - Pinus ER - TY - JOUR TI - The microstructure of almond (Prunus dulcis (Mill.) D.A. Webb cv. 'Nonpareil') cotyledon AU - Young, CT AU - Schadel, WE AU - Pattee, HE AU - Sanders, TH T2 - LEBENSMITTEL-WISSENSCHAFT UND-TECHNOLOGIE-FOOD SCIENCE AND TECHNOLOGY AB - Microstructure of almond (Prunus dulcis (Mill.) D.A. Webb cv. ‘Nonpareil’) cotyledon was observed with light, scanning and transmission electron microscopy. The objective of this study was to characterise almond cotyledon surfaces as well as to describe internal and subcellular organisation. The testa has an outer epidermis, which consists of relatively large thin-walled cells, which range from 100 to 300 μm in width. The major portion of the testa consists of approximately 14–20 layers of flattened parenchymal cells with the total thickness of the layers ranging from 80 to 120 μm. The remainder of the testa was comprised of a small amount of vascular tissue. The embryo consisted primarily of parenchymal tissue with relatively thin cell walls (1–3 μm in thickness) and a small amount of provascular tissue. Protein bodies up to 12 μm in width and spaces once occupied by lipid bodies up to 3 μm in width were present in all cells of the embryo. DA - 2004/// PY - 2004/// DO - 10.1016/j.lwt.2003.09.007 VL - 37 IS - 3 SP - 317-322 SN - 0023-6438 KW - protein body KW - lipid body KW - light microscopy KW - scanning electron microscopy KW - transmission electron microscopy ER - TY - JOUR TI - The influence of high-nitrogen forages on the voluntary feed intake of sheep AU - Stevens, D. R. AU - Burns, J. C. AU - Fisher, D. S. AU - Eisemann, J. H. T2 - Journal of Animal Science AB - The objective of this research was to examine the effect of high concentrations of nonprotein nitrogen (NPN) on the voluntary food intake of sheep fed high-quality grasses. Wether lambs (n = 6 per treatment) were fed dried switchgrass (Panicum virgatum L.; Exp. 1) or dried tall fescue (Festuca arundinacea Schreb.; Exp. 2). In both experiments, urea was added to the dried forage at 0 (control), 12, or 24 g of N/kg of DM to increase the NPN concentration. Acid detergent fiber concentrations were 305 g/kg of DM in both experiments, although DM digestibility was 663 and 618 g/kg of DM in Exp. 1 and Exp. 2, respectively. Voluntary feed intake of the control forage was 28.2 and 19.1 g/kg of BW in Exp. 1 and Exp. 2, respectively, and decreased for the high-urea treatments to 25.2 and 16.2 g/kg of BW in Exp. 1 (P = 0.07) and Exp 2 (P = 0.03), respectively. Total feed N concentrations increased from 29.5 g to 45.7 g of N/kg of DM in Exp. 1 (P < 0.01) and from 28.4 to 55.9 g of N/kg of DM in Exp. 2 (P < 0.01). Nonprotein N concentrations increased from 28.3 to 53.8% of the total N in switchgrass diets (Exp. 1; P < 0.01), and from 26.4 to 64.0% in tall fescue diets (Exp. 2; P < 0.01). Plasma urea concentrations of the lambs increased from 3.1 to 6.6 mM (Exp. 1; P < 0.01) and from 2.9 to 5.8 mM (Exp. 2; P < 0.01) as the amount of urea added to the diets increased. These changes resulted in an increase in plasma osmolality from 298 to 307 mOsm/kg (Exp. 1; P = 0.04), and from 299 to 307 mOsm/kg (Exp. 2; P = 0.06). Increasing feed N and NPN concentrations through the addition of urea caused a significant decrease in the voluntary feed intake of sheep fed tall fescue and switchgrass. These responses showed no significant cause-and-effect relationship between voluntary feed intake, plasma urea concentrations, and plasma osmolality. DA - 2004/// PY - 2004/// DO - 10.2527/2004.8251536x VL - 82 IS - 5 SP - 1536-1542 ER - TY - JOUR TI - Stream nitrogen changes in an eastern Coastal Plain watershed AU - Stone, K. C. AU - Hunt, P. G. AU - Novak, J. M. AU - Johnson, M. H. AU - Watts, D. W. AU - Humenik, F. J. T2 - Journal of Soil & Water Conservation DA - 2004/// PY - 2004/// VL - 59 IS - 2 SP - 66-72 ER - TY - JOUR TI - Speciation of hepatic Zn in trout exposed to elevated waterborne Zn using X-ray absorption spectroscopy AU - Beauchemin, S AU - Hesterberg, D AU - Nadeau, J AU - McGeer, JC T2 - ENVIRONMENTAL SCIENCE & TECHNOLOGY AB - The long-term impacts of chronic metal exposure for aquatic biota are not well understood, partly due to a lack of understanding of metal speciation within tissues. The objective of this study was to determine hepatic Zn speciation of rainbow trout (Oncorhnychus mykiss) exposed to Zn- enriched water in relation to unexposed (control) fish, through direct analysis of freeze-dried liver samples using synchrotron X-ray absorption spectroscopy (XAS). Juvenile rainbow trout (n=30) were exposed to Zn in a two-step process, 200 μg L-1 for 14 days, followed by 370 μg L-1 for 23 days. Thirty other trout were grown in a control treatment (10 μg Zn L-1). At the end of the experiment, three liver samples per treatment were collected, freeze-dried, ground, and mixed homogeneously. Although Zn concentration was higher in the Zn-exposed livers than in the control livers (22.32 vs 13.73 mg kg-1, respectively; p < 0.05), Zn speciation was similar for both groups. Extended X-ray absorption fine structure (EXAFS) spectroscopy indicated that Zn was coordinated to 4 sulfur atoms with an average Zn−S bond distance of 2.31 ± 0.02 Å. Sulfur K-XANES analysis confirmed that S was predominantly in reduced organic form analogous to cysteine. Our results are consistent with previous evidence for Zn(II) bonding to S in metallothionein proteins. These results suggest that the mechanisms for dealing with the extra load of bioaccumulated Zn in high exposure conditions were the same as in the control group. DA - 2004/3/1/ PY - 2004/3/1/ DO - 10.1021/es034979a VL - 38 IS - 5 SP - 1288-1295 SN - 1520-5851 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-1442325544&partnerID=MN8TOARS ER - TY - JOUR TI - Ambient ammonia and ammonium aerosol across a region of variable ammonia emission density AU - Walker, JT AU - Whitall, DR AU - Robarge, W AU - Paerl, HW T2 - ATMOSPHERIC ENVIRONMENT AB - We present 1 year of ambient ammonia (NH3), ammonium (NH4+), hydrochloric acid (HCl), chloride (Cl−), nitric acid (HNO3), nitrate (NO3−), nitrous acid (HONO), sulfur dioxide (SO2), and sulfate (SO42−) concentrations at three sites in the Coastal Plain region of North Carolina. The three sites, Clinton, Kinston, and Morehead City, are located in counties with total NH3 emission densities of 4800, 2280, and 320 kg NH3-N km−2 yr−1, respectively. Average NH3 concentrations were 5.32, 2.46, and 0.58 μg m−3 at Clinton, Kinston, and Morehead City, respectively. Average NH4+ concentrations were 1.84, 1.25, and 0.91 μg m−3, and total concentrations of inorganic (NH4++NO3−+ SO42−+Cl−) particulate matter with aerosol diameters <2.5 μm (PM2.5) were 8.66, 6.35, and 5.31 μg m−3 at Clinton, Kinston, and Morehead City, respectively. NH3 concentrations were highest during the summer at all sites, with summer-to-winter concentration ratios of 2.40, 5.70, and 1.70 at Clinton, Kinston, and Morehead City, respectively. NH3 concentrations were higher at night at the Clinton site, during the day at the Kinston site, and day vs. night concentrations were similar at the Morehead City site. NH4+ concentrations were highest during the winter at all sites, though this may not be representative of all years. Average daytime concentrations of NH4+ were similar to night values at all sites. NH4+ aerosol was primarily associated with SO42− at all sites, though the degree of SO42− neutralization was highest at Clinton and lowest at Morehead City. NH4+ aerosol formation appeared to be acid-gas-limited at the Clinton site during all seasons and during the spring and summer at the Kinston site. This study shows that agricultural NH3 emissions influence local ambient concentrations of NH3 and PM2.5. DA - 2004/3// PY - 2004/3// DO - 10.1016/j.atmosenv.2003.11.027 VL - 38 IS - 9 SP - 1235-1246 SN - 1352-2310 KW - atmospheric nitrogen KW - agricultural emissions KW - acid gases KW - PM2.5 KW - denuders ER - TY - JOUR TI - XANES determination of adsorbed phosphate distribution between ferrihydrite and boehmite in mixtures AU - Khare, N. AU - Hesterberg, Dean AU - Beauchemin, S. AU - Wang, S. L. T2 - Soil Science Society of America Journal AB - Iron‐ and Al‐(hydr)oxide minerals are important sorbents for retaining PO 4 in soils. Our objective was to determine the distribution of adsorbed PO 4 between ferrihydrite and boehmite in aqueous mixtures of these minerals. Phosphate was adsorbed in aqueous suspensions up to maximum concentrations of 1860, 850, and 1420 mmol kg −1 for ferrihydrite, boehmite, and 1:1 (by mass) mixtures of these minerals at pH 6. The solids were analyzed as moist pastes using P K‐XANES (X‐ray absorption near edge structure) spectroscopy. The adsorption isotherm for the mixed‐mineral suspensions could essentially be described as a linear combination of Freundlich isotherm models for each single‐mineral system, indicating negligible mineral interactive effects on PO 4 adsorption in the mixtures. X‐ray absorption near edge structure spectra for PO 4 adsorbed on ferrihydrite or in ferrihydrite/boehmite mixtures showed a pre‐edge feature at approximately 2146 eV that was absent in boehmite systems. Linear combination fitting of the pre‐edge region of XANES spectra for mixtures with average spectra for PO 4 adsorbed on boehmite or ferrihydrite alone, indicated that 59 to 97% of the PO 4 was adsorbed on ferrihydrite in the mixtures. With increasing concentration of adsorbed PO 4 in the mineral mixtures, the concentration adsorbed on the ferrihydrite component increased linearly. Phosphate distribution trends in the mixtures suggested an affinity preference for ferrihydrite at the lowest adsorbed PO 4 concentration (100 mmol kg −1 minerals), no affinity preference for either mineral at intermediate concentrations (200 to 600 mmol PO 4 kg −1 ), and the possibility of a surface precipitate involving Al at the highest concentration (1300 mmol PO 4 kg −1 ). DA - 2004/// PY - 2004/// DO - 10.2136/sssaj2004.4600 VL - 68 IS - 2 SP - 460–469 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-1542291512&partnerID=MN8TOARS ER - TY - JOUR TI - Development of highly regenerable callus lines and biolistic transformation of turf-type common bermudagrass [Cynodon dactylon (L.) Pers.] AU - Li, L AU - Qu, R T2 - PLANT CELL REPORTS DA - 2004/1// PY - 2004/1// DO - 10.1007/s00299-003-0706-6 VL - 22 IS - 6 SP - 403-407 SN - 0721-7714 KW - bermudagrass KW - embryogenic KW - plant regeneration KW - transgenic KW - turfgrass ER - TY - JOUR TI - Weed management in imidazolinone-resistant corn with imazapic AU - Ducar, JT AU - Wilcut, JW AU - Richburg, JS T2 - WEED TECHNOLOGY AB - Field studies were conducted in 1992 and 1993 to evaluate imazapic alone and in postemergence (POST) mixtures with atrazine or bentazon for weed control in imidazolinone-resistant corn treated with carbofuran. Nicosulfuron and nicosulfuron plus atrazine also were evaluated. Imazapic at 36 and 72 g ai/ha controlled large crabgrass 85 and 92%, respectively, which was equivalent to control obtained with nicosulfuron plus atrazine. Imazapic at the higher rate controlled large crabgrass better than nicosulfuron alone. Imazapic at 36 and 72 g/ha controlled Texas panicum 88 and 99%, respectively, and at the higher rate control was equivalent to that obtained with nicosulfuron alone or in mixture with atrazine. Imazapic plus bentazon POST controlled Texas panicum less than imazapic at the lower rate applied alone. Redroot pigweed was controlled 100% with all herbicide treatments. Imazapic at either rate alone or in tank mixture with bentazon or atrazine controlled prickly sida >99%, which was superior to control obtained with nicosulfuron or nicosulfuron plus atrazine. Smallflower, entireleaf, ivyleaf, pitted, and tall morningglories were controlled 96% or greater with all herbicide treatments except nicosulfuron alone. Sicklepod control was >88% with all imazapic treatments, whereas control from nicosulfuron alone was 72%. Corn yields were improved by the addition of POST herbicides with no differences among POST herbicide treatments. DA - 2004/// PY - 2004/// DO - 10.1614/WT-03-204R VL - 18 IS - 4 SP - 1018-1022 SN - 1550-2740 KW - imidazolinone-resistant corn ER - TY - JOUR TI - Residue decomposition and nutrient release dynamics from two tropical forage legumes in a Kenyan environment AU - Njunie, MN AU - Wagger, MG AU - Luna-Orea, P T2 - AGRONOMY JOURNAL AB - Soil fertility decline is one of the factors limiting food production on the east coast of Africa. Increased awareness by smallholder farmers of the role of legumes as sources of food and fodder and for soil fertility improvement has stimulated research on the influence of herbaceous legumes in various cropping systems. Decomposition and nutrient release from foliage of legume species clitoria ( Clitoria ternatea L.) and dolichos ( Lablab purpureus L.) planted in monoculture and as an intercrop with tropical food crops cassava ( Manihot esculenta Crantz) and maize (Zea mays L.) were evaluated under field conditions in fine‐loamy, kaolinitic, isohyperthermic, arenic Paleustalfs. The nylon mesh bag technique was used to obtain data to calculate the residue decomposition and nutrient release rates of the clitoria foliage cut every 6 or 10 wk and dolichos foliage cut at 2 or 4 mo. Asymptotic models provided the best fit for both dry matter decomposition and nutrient release. Legume residue decomposition rates ( k ) were unaffected by cropping system, with values of 0.2 and 0.5 wk −1 for clitoria and dolichos, respectively. Across cutting management strategies, the general order of nutrient release for clitoria at 6 or 10 wk was K > P > Mg > N; while that of dolichos was K > Mg > P > N and K > P > Mg > N for cuts at 2 and 4 mo, respectively. Overall, the residue N, P, and Mg release curves became asymptotic shortly after 60% of the nutrients had been released. Clitoria and dolichos showed their potential to become sources of nutrients for associated crops while protecting the soil surface. DA - 2004/// PY - 2004/// DO - 10.2134/agronj2004.1073 VL - 96 IS - 4 SP - 1073-1081 SN - 1435-0645 ER - TY - JOUR TI - Plant breeding requirements for applied molecular biology AU - Goodman, MM T2 - CROP SCIENCE AB - Crop ScienceVolume 44, Issue 6 p. 1913-1914 Symposium on Genomics and Plant Breeding: The Experience of the Initiative for Future Agricultural and Food System Plant Breeding Requirements for Applied Molecular Biology Major M. Goodman, Corresponding Author Major M. Goodman maize_resources@ncsu.edu Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695Corresponding author (maize_resources@ncsu.edu)Search for more papers by this author Major M. Goodman, Corresponding Author Major M. Goodman maize_resources@ncsu.edu Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695Corresponding author (maize_resources@ncsu.edu)Search for more papers by this author First published: 01 November 2004 https://doi.org/10.2135/cropsci2004.1913Citations: 23Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume44, Issue6November–December 2004Pages 1913-1914 RelatedInformation DA - 2004/// PY - 2004/// DO - 10.2135/cropsci2004.1913 VL - 44 IS - 6 SP - 1913-1914 SN - 1435-0653 ER - TY - JOUR TI - Growth and localized energy status in phosphorus-stressed soybean AU - Chiera, JM AU - Thomas, JF AU - Rufty, TW T2 - JOURNAL OF PLANT NUTRITION AB - Abstract In plants experiencing phosphorus (P) stress, ATP concentrations can be reduced significantly and shoot growth is strongly restricted, raising the possibility that energy availability is responsible for the growth inhibition. Experiments were conducted to investigate the relationship between P deprivation and energy availability in tissues involved in the growth response. Young soybean (Glycine max [L.] Merr. cv. Ransom) plants were deprived of P for 32 days. Leaf initiation and individual leaf expansion were followed along with localized P and ATP concentrations. Tissue analyses revealed preferential distribution of P to the root, which accompanied a decline in the shoot to root dry weight ratio. Even though P concentrations in all shoot tissues dropped sharply, ATP concentrations and energy charge in the shoot meristem region were maintained similar to controls for an extended period when leaf initiation slowed. In the first trifoliolate leaf, ATP and energy charge remained at control levels during the expansion phase, but expansion was inhibited by 50%. Furthermore, ATP levels in root tips were decreased almost 30%, yet growth of the root system was equal to or greater than the control. The absence of a positive correlation between ATP levels and growth responses in the different tissues suggests that energy availability is not a primary factor limiting growth under P stress conditions. The results, along with others from previous experiments, support the notion that a signaling mechanism, as yet unidentified, controls down regulation of cell division in shoot growth regions. DA - 2004/// PY - 2004/// DO - 10.1081/LPLA-200030007 VL - 27 IS - 11 SP - 1875-1890 SN - 1532-4087 ER - TY - PCOMM TI - Slow, remarkable, and receptive AU - Cook, M. G. DA - 2004/// PY - 2004/// SP - 49A ER - TY - JOUR TI - Nitrogen use in Tifway bermudagrass, as affected by trinexapac-ethyl AU - Fagerness, MJ AU - Bowman, DC AU - Yelverton, FH AU - Rufty, TW T2 - CROP SCIENCE AB - Nutrient movement from turfgrass systems into surface and ground water is a public concern. Data indicate that actively growing turf rapidly immobilizes applied N, thus restricting nutrient movement. It is possible, however, that growth suppression with plant growth regulators (PGRs) could reduce N demand and thus N uptake, resulting in greater leaching losses. An experiment was conducted with column lysimeters to investigate the effects of trinexapac‐ethyl (TE) on nitrate leaching and N‐use efficiency in Tifway bermudagrass ( Cynodon dactylon × C. transvaalensis ). The experiment was conducted in a growth chamber with day/night temperature set at 29/24°C and a 12‐h photoperiod. Trinexapac‐ethyl was applied twice at 4‐wk intervals at 0.11 kg a.i. ha −1 Ammonium nitrate (AN) was applied at 50 kg N ha −1 2 wk after each TE application, and again 6 wk after the second TE application. Separate sets of columns received 15 N‐labeled AN for the first two applications. Irrigation was scheduled to provide a leaching fraction of ≈50%; leachate was collected after each irrigation and analyzed for nitrate and ammonium. Cumulative nitrate leaching was unaffected by TE after the first two N applications, but was reduced ≈60% by TE following the third N application. Trinexapac‐ethyl reduced 15 N allocation to clippings by ≈25% and increased 15 N allocation to roots and rhizomes; total recovery of applied 15 N in tissues was ≈65%. Results demonstrate chemical growth suppression with TE does not reduce N uptake or increase nitrate leaching from bermudagrass. DA - 2004/// PY - 2004/// DO - 10.2135/cropsci2004.5950 VL - 44 IS - 2 SP - 595-599 SN - 1435-0653 ER - TY - JOUR TI - Microbial nitrogen transformations in response to treated dairy waste in agricultural soils AU - Shi, W AU - Miller, BE AU - Stark, JM AU - Norton, JM T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - Dairy wastes are commonly applied to croplands as N fertilizers, but the dynamics of N release and transformations during the growing season are difficult to predict. We compared N mineralization kinetics and examined microbial N transformations in soil receiving dairy‐waste compost vs. lagoon effluent. Mineralization kinetics was examined with a 70‐d laboratory incubation, and a first‐order model was used to derive mineralization parameters. Measurements of N transformations were conducted with 15 N pool dilution techniques in silage corn field plots that were unfertilized or fertilized with ammonium sulfate, lagoon effluent, or compost at two rates equivalent to 100 or 200 kg available N ha −1 The N mineralization potential was higher and the first‐order rate constant was lower in soil receiving compost than lagoon effluent. Approximately 6% of compost N was mineralized within 2.5 mo; in contrast, up to 90% lagoon effluent organic N was released. However, silage yield was greatest in the compost treatment, showing that synchronization of N availability is as important as the amount mineralized. The field 15 N measurements indicated that microbial NO − 3 consumption was negligible despite the treatments. Microbial NH + 4 immobilization in soil receiving dairy wastes was similar to that in soil unfertilized or fertilized with inorganic N. Soil treated with the high‐rate compost had the highest rates of mineralization and nitrification, which led to the highest soil NO − 3 accumulation. Our observations suggest that peak plant demand is met by the compost N; however, its high N mineralization potential makes the management of dairy compost a difficult task. DA - 2004/// PY - 2004/// DO - 10.2136/sssaj2004.1867 VL - 68 IS - 6 SP - 1867-1874 SN - 0361-5995 ER - TY - JOUR TI - Hydrodynamic assessment of various types of baffles in a sediment detention pond AU - Thaxton, C.S. AU - Calantoni, J. AU - McLaughlin, R.A. T2 - Transactions of the ASAE AB - We assess the relative improvement to the sediment trapping effectiveness of apermanent-pool sediment detention pond due to the installation of baffles composed ofdifferent materials commonly used on construction sites. A suite of experiments wasperformed at the Sediment and Erosion Control Research and Education Facility(SECREF) at North Carolina State University in which an acoustic Doppler velocimeterwas used to record steady-state flow velocity and signal-to-noise ratio data at 50 gridpoints within the pond at three different fixed input flow rates. The maximum mean flowvelocity in the pond, averaged over all input flow rates, is reduced to roughly 25% of thefree flow maximum mean flow velocity by the presence of a jute germination geotextilebacked by coir fiber. A standard tree protection fence, folded and tied together into threelayers for stability, reduces the free flow maximum mean velocity by 35%, while astandard silt fence reduces the free flow maximum mean velocity by 45%. Signal-tonoiseratio degradation along the length of the pond confirms that the installed jute/coirand tree baffles most effectively reduce the concentration of turbulent density frontsresponsible for Doppler backscatter over that of silt baffles or free flow. In addition,analysis of the transverse velocity variance and vertical velocity gradients for eachexperiment further demonstrates that the jute/coir and tree baffles most effectively diffuseinflow momentum. The results of our analysis are used to project a theoretical sedimenttrapping efficiency based on Stoke's settling. DA - 2004/// PY - 2004/// DO - 10.13031/2013.15614 VL - 47 IS - 3 SP - 741–749 ER - TY - JOUR TI - First report of stem and leaf blight caused by Sclerotinia minor on Geranium carolinianum in North Carolina. AU - Hollowell, JE AU - Shew, BB T2 - PLANT DISEASE AB - The soilborne fungus Sclerotinia minor Jagger is a major pathogen of peanut (Arachis hypogaea L.) in North Carolina and overwinters in soil, on crop debris, or on winter annual weed species (1). Bleached stems and small, black sclerotia are typically seen on peanut plants infected by S. minor. Carolina geranium (Geranium carolinianum L.) is one of several winter annual weed species found during winter fallow in peanut production areas of northeastern North Carolina. During a March 2002 survey of previously harvested peanut fields, plants of Carolina geranium were observed with typical signs and symptoms of infection caused by S. minor. Symptomatic plants with bleached stems and signs of small, black sclerotia were collected in the field and returned to the laboratory. Pathogen isolation and fungal identification were performed from the symptomatic tissues by placing 1- to 2-cm sections of stems on potato dextrose agar after rinsing with tap water and towel drying. Pure cultures of S. minor were obtained and observed to have white, fluffy mycelium and small, black irregular-shaped sclerotia (<2 mm) produced abundantly and scattered over the culture surface. Pathogenicity was tested by inoculating stems of three symptom-free Carolina geranium plants with 2-day-old fungal mycelium from pure isolation. Mycelial agar plugs, 4 mm in diameter, were held in place with self-sticking bandaging gauze. Plants were misted, enclosed in plastic bags, and incubated at ambient temperature (24°C) on the laboratory counter top. Bleached water-soaked lesions developed on the stems, and leaves became chlorotic after 8 days. Following 8 days of incubation, S. minor was reisolated from all inoculated plants. Three noninoculated plants remained healthy over the incubation period. The performance of Koch's postulates confirmed that Carolina geranium is a host of S. minor. To our knowledge, this is the first report of S. minor on G. carolinianum. These results indicate that G. carolinianum is a potential overwintering host for S. minor in peanut fields. Infected weed hosts allow reproduction of the fungus in the winter, potentially resulting in more disease on peanut planted in the spring. Reference: (1) J. E. Hollowell et al. Plant Dis. 87:197, 2003. DA - 2004/3// PY - 2004/3// DO - 10.1094/PDIS.2004.88.3.312B VL - 88 IS - 3 SP - 312-312 SN - 1943-7692 ER - TY - JOUR TI - Diversity of Chalqueno maize AU - Herrera-Cabrera, B. E. AU - Castillo-Gonzalez, F. AU - Sanchez-Gonzalez, J. J. AU - Hernandez-Casillas, J. M. AU - Ortega-Pazkca, R. A. AU - Goodman, M. M. T2 - Agrociencia DA - 2004/// PY - 2004/// VL - 38 IS - 2 SP - 191-206 ER - TY - JOUR TI - A chitinase from Tex6 maize kernels inhibits growth of Aspergillus flavus AU - Moore, KG AU - Price, MS AU - Boston, RS AU - Weissinger, AK AU - Payne, GA T2 - PHYTOPATHOLOGY AB - The maize inbred Tex6 has resistance to colonization and aflatoxin accumulation by Aspergillus flavus. A protein inhibitory to growth of A. flavus has been identified from aqueous extracts of mature Tex6 seeds. This study reports the purification of a chitinase associated with this inhibitory activity to electrophoretic homogeneity and the further characterization of its properties. The inhibitory protein, which has an M r of 29,000, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, is an endochitinase that is also capable of exochitinase activity. The enzyme has an optimal pH of 5.5 and a temperature optimum of 45°C. Chitinase activity in maize kernels peaked approximately 36 days after pollination. The Tex6 chitinase purified in this study is capable of inhibiting the growth of A. flavus by 50% at a concentration of 20 μg/ml. Our data indicate that chitinase activity in Tex6 kernels makes a major contribution to the antifungal activity in this maize genotype. Partial peptide sequence of the chitinase showed it to differ from previously reported chitinases. DA - 2004/1// PY - 2004/1// DO - 10.1094/PHYTO.2004.94.1.82 VL - 94 IS - 1 SP - 82-87 SN - 1943-7684 ER - TY - JOUR TI - The influence of defoliation timing on yields and quality of two cotton cultivars AU - Faircloth, J. C. AU - Edmisten, K. L. AU - Wells, R. AU - Stewart, A. M. T2 - Crop Science AB - The timing of certain cotton ( Gossypium hirsutum L.) management practices varies according to the yield potential and quality characteristics associated with a variety. A defoliation timing study was performed to (i) determine if certain cultivars respond differently to defoliation timings and (ii) compare the use of the open boll percentage at defoliation (OBPD), nodes above cracked boll (NACB), and micronaire readings at defoliation for their effectiveness in timing defoliation. The study was conducted in 1999, 2000, and 2001. Treatments consisted of two proprietary cultivars (ST 474 and DP 5409), each defoliated on the basis of OBPD measurements. At the time of defoliation, NACB was recorded and lint samples were retained for later high volume instrumentation (HVI) analysis. Neither variety produced consistently higher yields than the other in this study. In 2000, delaying defoliation from 40 to 60 OBPD would have resulted in a significant addition of approximately 75 kg lint ha −1 for either variety. Stoneville 474 micronaire was highest in all years suggesting that timely defoliation is more critical to ST 474 cotton compared with DP 5409 in years when overall conditions are favorable for high micronaire. DP 5409 fiber length (UHM) values were consistently higher than ST 474 and UHM was unaffected by changes in OBPD values regardless of variety. Stoneville 474 had higher uniformity index (UI) values in all three years and delaying defoliation produced mixed results. The data demonstrate that proper defoliation timing strategies aimed at optimizing quality can vary across varieties. Proper defoliation timing in the two varieties examined in this study varied little with respect to yields. Both NACB and micronaire readings taken at defoliation were more effective for timing defoliation to optimize micronaire readings than OBPD. DA - 2004/// PY - 2004/// DO - 10.2135/cropsci2004.1650 VL - 44 IS - 1 SP - 165-172 ER -