@article{sinclair_specht_cassman_purcell_rufty_2023, title={Comment on ?Soybean photosynthesis and crop yield are improved by accelerating recovery from photoprotection?}, volume={379}, ISSN={["1095-9203"]}, DOI={10.1126/science.ade8506}, abstractNote={
            De Souza
            et al.
            (Research Articles, 19 Aug 2022, adc9831) recently claimed major soybean yield increases resulting from transformation of the nonphotochemical quenching mechanism of photosynthesis. However, there is little basis for the premise that such a transformation would result in yield increase. The field experiment was flawed and does not provide evidence for increases in crop yield.
          }, number={6634}, journal={SCIENCE}, author={Sinclair, Thomas and Specht, James and Cassman, Kenneth and Purcell, Larry and Rufty, Thomas}, year={2023}, month={Feb} }
 @book{sinclair_rufty_2022, title={Bringing Skepticism to Crop Science}, ISBN={9783031144134 9783031144141}, ISSN={2211-808X 2211-8098}, url={http://dx.doi.org/10.1007/978-3-031-14414-1}, DOI={10.1007/978-3-031-14414-1}, abstractNote={This book serves as a reminder to crop scientists and others that open, clear-minded assessments of the entirety of evidence concerning a hypothesis.}, journal={SpringerBriefs in Agriculture}, publisher={Springer International Publishing}, author={Sinclair, Thomas and Rufty, Thomas W.}, year={2022} }
 @article{twiddy_taggart_reynolds_sharkey_rufty_lobaton_bozkurt_daniele_2022, title={Real-Time Monitoring of Plant Stalk Growth Using a Flexible Printed Circuit Board Sensor}, ISSN={["1930-0395"]}, DOI={10.1109/SENSORS52175.2022.9967167}, abstractNote={Monitoring of plant growth within agriculture is essential for ensuring the survival of crops and optimization of resources in the face of environmental and industrial challenges. Herein, we describe a low-cost and easily deployable flexible circuit board sensor for measurement of plant stalk growth, providing for remote tracking of plant development on an industrial scale. Three circuit topologies and measurement strategies - “ladder-type,” “multiplex-type,” and “mixed-type” - are initially assessed off-plant in a simulated growth experiment. Further development of the “multiplex-type” sensor and on-plant validation demonstrates its ability to quantify stalk growth as a proxy for plant development.}, journal={2022 IEEE SENSORS}, author={Twiddy, Jack and Taggart, Matthew and Reynolds, James and Sharkey, Chris and Rufty, Thomas and Lobaton, Edgar and Bozkurt, Alper and Daniele, Michael}, year={2022} }
 @article{rosas-anderson_sinclair_rufty_2021, title={Leaf expansion and recovery from soil drying in soybean genotypes}, volume={35}, ISSN={["1542-7536"]}, DOI={10.1080/15427528.2020.1802801}, abstractNote={ABSTRACT Maintenance and recovery of the canopy area when drought stress is relieved may be critical for maintaining high productivity. In this study, experiments were conducted in controlled environments to evaluate leaf expansion and leaf necrosis of five soybean (Glycine max Merr. L.) genotypes undergoing soil-drying, followed by re-watering. Water-deficit stress was imposed by limiting daily watering. When soil water decreased to a severe defined level, full watering resumed for five days. Measurements of leaf expansion and necrosis were taken during water-deficit and recovery periods. Genotypic differences for critical soil-water thresholds at which leaf expansion rates decline were detected. Genotype “Benning” showed the sensitivity of expansion rates to soil-drying while “Geden Shirazu” showed leaf expansion tolerance to soil drying. All genotypes recovered expansion rates within one or two days. During recovery, the recently released cultivar ‘USDA-N8002ʹ had the highest leaf expansion rate among genotypes, compared to its well-watered plants. The high recovery potential of USDA-N8002 was largely attributable to high nighttime expansion recovery. This elite drought-tolerant cultivar, along with the commercial cultivar Benning, experienced the lowest levels of leaf necrosis. While all genotypes exhibited rapid recovery in leaf expansion following drought, variation in the extent of recovery and level of leaf necrosis indicates that these characteristics can be exploited to enhance drought resilience.}, number={1}, journal={JOURNAL OF CROP IMPROVEMENT}, author={Rosas-Anderson, Pablo and Sinclair, Thomas R. and Rufty, Thomas W.}, year={2021}, month={Jan}, pages={96–110} }
 @article{xia_rufty_shi_2021, title={Predominant Microbial Colonizers in the Root Endosphere and Rhizosphere of Turfgrass Systems: Pseudomonas veronii, Janthinobacterium lividum, and Pseudogymnoascus spp.}, volume={12}, ISSN={["1664-302X"]}, DOI={10.3389/fmicb.2021.643904}, abstractNote={Microbes can colonize plant roots to modulate plant health and environmental fitness. Thus, using microbes to improve plant adaptation to biotic and abiotic stresses will be promising to abate the heavy reliance of management systems on synthetic chemicals and limited resource. This is particularly important for turfgrass systems because intensive management for plant available nutrients (e.g., nitrogen), water, and pest control is necessary to maintain a healthy and aesthetic landscape. However, little is known on microbial species and host compatibility in turfgrass root endosphere and rhizosphere. Here, by using marker gene high throughput sequencing approaches we demonstrated that a few bacterial and fungal species prevailed the root endosphere and rhizosphere and were of a broad host spectrum. Irrespective of turfgrass species (bermudagrass, ultradwarf bermudagrass, creeping bentgrass, and tall fescue), defoliation intensities (i.e., mowing height and frequency), turfgrass sites, and sampling time, Pseudomonas veronii was predominant in the root endosphere, constituting ∼38% of the total bacterial community, which was much higher than its presence in the bulk soil (∼0.5%) and rhizosphere (∼4.6%). By contrast, Janthinobacterium lividum and fungal species of the genus Pseudogymnoascus were more abundant in the rhizosphere, constituting ∼15 and ∼ 39% of the total bacterial and fungal community, respectively, compared to their respective presence in the bulk soil (∼ 0.1 and 5%) and root endosphere (∼ 0.8 and 0.3%). Such stark contrasts in the microbiome composition between the root endosphere, rhizosphere, and bulk soil were little influenced by turfgrass species, suggesting the broad turfgrass host compatibility of these bacterial and fungal species. Further, their dominance in respective niches were mutually unaffected, implying the possibility of developing a multiple species formula for coping turfgrass with environmental stresses. These species were likely involved in controlling pests, such as infectious nematodes and fungi, decomposing root debris, and helping turfgrass water and nutrient uptake; yet these possibilities need to be further examined.}, journal={FRONTIERS IN MICROBIOLOGY}, author={Xia, Qing and Rufty, Thomas and Shi, Wei}, year={2021}, month={Mar} }
 @article{rufty_sinclair_2020, title={"Cycling of amino-nitrogen and other nutrients between shoots and roots in cereals-A possible mechanism integrating shoot and root in the regulation of nutrient uptake" by HD Cooper and DT Clarkson, Journal of Experimental Botany (1989) 40:753-762}, volume={60}, ISSN={["1435-0653"]}, DOI={10.1002/csc2.20192}, abstractNote={Abstract}, number={5}, journal={CROP SCIENCE}, author={Rufty, Thomas W. and Sinclair, Thomas R.}, year={2020}, pages={2192–2194} }
 @article{rosas-anderson_sinclair_locke_carter_rufty_2020, title={Leaf gas exchange recovery of soybean from water-deficit stress}, volume={34}, ISSN={1542-7528 1542-7536}, url={http://dx.doi.org/10.1080/15427528.2020.1764429}, DOI={10.1080/15427528.2020.1764429}, abstractNote={ABSTRACT As the risk of drought attributable to climate change increases, the development of high-yielding, drought-adapted cultivars will be critical for minimizing yield losses in crops like soybean (Glycine max (L.) Merr.). In this study, the ability of soybean genotypes to recover transpiration and leaf gas exchange capacity following re-watering from soil drying was investigated. The plants were subjected to controlled water-deficit stress and recovery in growth-chamber experiments. Transpiration was measured on five soybean genotypes and photosynthesis rates on two select genotypes. After water re-supply, transpiration was initially low but increased until a stable rate was reached on day 3, to about 50% to 100% of the rates of reference plants that had not been stressed. The largest difference in maximum transpiration recovery was between the varieties USDA-N8002 and Benning compared to the landrace Geden Shirazu, with Geden Shirazu having the lowest recovery. Photosynthesis and vapor-pressure-deficit response measurements did not show that restricted plant stomatal conductance was responsible for the limitation observed in Geden Shirazu recovery. Since all genotypes showed rapid recovery from water-deficit stress in 3 d, more rapid recovery was not indicated as a major candidate for improving soybean drought tolerance. However, the extent of recovery varied among genotypes and those genotypes that fully recovered to rates of well-watered plants such as Benning and USDA-N8002 would seemingly be advantageous for drought conditions.}, number={6}, journal={Journal of Crop Improvement}, publisher={Informa UK Limited}, author={Rosas-Anderson, Pablo and Sinclair, Thomas R. and Locke, Anna and Carter, Thomas E. and Rufty, Thomas W.}, year={2020}, month={May}, pages={785–799} }
 @article{xia_rufty_shi_2020, title={Soil microbial diversity and composition: Links to soil texture and associated properties}, volume={149}, ISSN={["0038-0717"]}, DOI={10.1016/j.soilbio.2020.107953}, abstractNote={Soil texture is an essential component of soil survey for estimating potentials and limitations of land use and management. It has been appreciated as an important predictor for numerous soil processes. However, its connections with the diversity and composition of the soil microbial community remain less understood. This work employed a marker gene high-throughput sequencing approach to determine soil texture-based patterns of bacterial and fungal distribution. Thirty-six intact soil cores were sampled from bermudagrass ecosystems across seven soil texture classes with sand fraction varying from 30.3 to 83.4% and clay fraction from 4.4 to 53.0%. These soil cores were arranged into three sets of equal numbers, and each set of 12 was subjected to three moisture regimes (dry spell, field moisture, and saturation-field capacity), respectively, for 15 days. Soil cores were further stratified into top and bottom sections, leading to a total of 72 samples with varying soil physical and chemical properties. Our data revealed that fungal alpha diversity was more strongly related to soil texture than bacterial alpha diversity, with fungal species richness and Shannon diversity being positively correlated with the sand fraction. Soil texture was the second most important factor after soil pH in shaping the soil microbial community. Relative abundances of some fungi (Basidiomycota and Eurotiomycetes) and filamentous bacteria (Actinobacteria, Chloroflexi) significantly increased with silt and/or clay content. The genetic potential for the degradation of organic compounds also appeared to be higher in finer textured soils than the coarse-textured soils. By identifying sand, silt or clay-preferred microbial taxa and characterizing mineral particle-dependent genetic potential of organic carbon degradation and nitrogen cycling, this work highlighted the significance of soil texture and texture-associated pores, and resource locality, in regulating microbial diversity and community composition.}, journal={SOIL BIOLOGY & BIOCHEMISTRY}, author={Xia, Qing and Rufty, Thomas and Shi, Wei}, year={2020}, month={Oct} }
 @misc{sinclair_rufty_lewis_2019, title={Increasing Photosynthesis: Unlikely Solution For World Food Problem}, volume={24}, ISSN={["1878-4372"]}, DOI={10.1016/j.tplants.2019.07.008}, abstractNote={Increasing the photosynthesis rate of plants has been recently revitalized as an approach for increasing grain crop yields and solving world food crises. The idea that photosynthesis is the key to increasing grain crop yields is not new. Considerable research in the 1970s and 1980s showed that carbon input was not limiting for crop growth and yield. Instead, the availability and uptake of water and nutrients were found to be critical for increasing grain yield, and that conclusion still applies today. In this Opinion article, nitrogen limitation is given particular attention because of its quantitative linkage with vegetative and reproductive growth and its essential role as a quantitative component of seeds.}, number={11}, journal={TRENDS IN PLANT SCIENCE}, author={Sinclair, Thomas R. and Rufty, Thomas W. and Lewis, Ramsey S.}, year={2019}, month={Nov}, pages={1032–1039} }
 @article{rosas-anderson_taggart_heitman_miller_sinclair_rufty_2018, title={Partitioning between evaporation and transpiration from Agrostis stolonifera L. during light and dark periods}, volume={260}, ISSN={["1873-2240"]}, DOI={10.1016/j.agrformet.2018.05.018}, abstractNote={Pressures on water availability for irrigation of turfgrasses continue in many parts of the United States as climate and weather patterns shift and populations increase. It is essential to understand underlying factors controlling water loss to more precisely predict irrigation requirements and develop new strategies for improving effective use of water. In this study, we investigate two key components of potential water loss from a bentgrass (Agrostis stolonifera L.) system that have not previously been examined in detail: 1) water loss in darkness, and 2) water loss through evaporation directly from the soil. The experiments were conducted in controlled environment chambers with intact cores from the field. An automated gravimetric system and soil moisture probes allowed precise measurements of water loss over ranges of vapor pressure deficits (VPD). The gravimetric and soil probe results indicated that substantial evapotranspiration occurred in darkness, at rates 40 to 60% of that in the light across VPDs. Simulations using field weather data from dry and humid environments indicated nighttime water loss rates would be expected to be 30 to 40% of that in the light. Using cores treated with a fast-acting, desiccating herbicide that eliminated transpiration but kept core resistances intact, evaporation directly from the soil surface was estimated to account for 40% of total water loss in the light and 60 to 70% in the dark. The results, collectively, indicated that water loss in darkness must be separately accounted for to accurately estimate daily evapotranspiration totals and irrigation requirements. Furthermore, because of the very high potential for evaporative water loss in the light and dark, efforts to improve water use efficiencies in the turfgrass system should include strategies that regulate both transpiration by the plant and evaporation from the soil surface.}, journal={AGRICULTURAL AND FOREST METEOROLOGY}, author={Rosas-Anderson, Pablo and Taggart, Matthew J. and Heitman, Joshua L. and Miller, Grady L. and Sinclair, Thomas R. and Rufty, Thomas W.}, year={2018}, month={Oct}, pages={73–79} }
 @article{sermons_sinclair_seversike_rufty_2017, title={Assessing transpiration estimates in tall fescue: The relationship among transpiration, growth, and vapor pressure deficits}, volume={137}, ISSN={["1873-7307"]}, DOI={10.1016/j.envexpbot.2017.02.003}, abstractNote={Limitations in water availability for irrigation due to drought and water-use regulations necessitate accurate approaches to estimate water use. An energy balance approach is commonly used that is inherently empirical and requires an ill-defined coefficient. An alternative is to use a relationship based on vapor pressure deficit (VPD) and plant growth to predict plant transpiration rate. This study was undertaken to evaluate these approaches for tall fescue (Festuca arundinacea Schreb.). Experiments examined differences in water loss of tall fescue plants when grown in three temperatures with varying vapor pressure deficit (VPD), and with treatments of low nutrition and of growth regulator trinexapac-ethyl, which depressed growth. Within a temperature, the low-nutrition and growth-regulator treatments greatly affected clipping mass, however water loss remained similar. In hydroponic experiments, treatments altering clipping mass did not necessarily change total plant growth. Hence, a challenge to using whole-plant growth for estimating transpiration of this grass is to accurately determine growth only from clipping data. Transpiration was positively correlated with VPD, especially within each temperature, but there were indications that the higher temperature treatments caused decreased plant control over transpiration. The instability of physiological control over transpiration highlights the potential limitations of both equations in estimating transpiration rates.}, journal={ENVIRONMENTAL AND EXPERIMENTAL BOTANY}, author={Sermons, Shannon M. and Sinclair, Thomas R. and Seversike, Thomas M. and Rufty, Thomas W.}, year={2017}, month={May}, pages={119–127} }
 @article{bagherzadi_sinclair_zwieniecki_secchi_hoffmann_carter_rufty_2017, title={Assessing, water-related plant traits to explain slow-wilting in soybean PI 471938}, volume={31}, ISSN={["1542-7536"]}, DOI={10.1080/15427528.2017.1309609}, abstractNote={ABSTRACT Soybean [Glycine max (L.) Merr.] genotype PI 471938 expresses a slow-wilting phenotype in the field, and the progeny of this genotype have shown to have high yield under water deficit conditions. However, the physiological basis for the slow-wilting trait in PI 471938 remains unclear, and failure to understand the causal mechanism may limit future breeding efforts. This study investigated three primary hypotheses for trait expression that could explain slow-wilting trait in PI 471938: (1) a low osmotic potential in the leaves allowing greater water retention, (2) high elastic modulus of leaves resulting in delayed development of wilting, and (3) high hydraulic conductance allowing rapid water redistribution in the plants. Experiments included three other soybean genotypes as references for the results obtained with PI 471938. Surprisingly, the results for PI 471938 did not prove to be unique as compared to the other three tested genotypes for any of the three hypotheses. These negative results indicate that a hypothesis outside the usual candidates describing plant water transport, possibly anatomical features related to specific water transport properties, is required to explain slow-wilting in PI 471938.}, number={3}, journal={JOURNAL OF CROP IMPROVEMENT}, author={Bagherzadi, Laleh and Sinclair, Thomas R. and Zwieniecki, Maciej and Secchi, Francesca and Hoffmann, William and Carter, Thomas E. and Rufty, Thomas W.}, year={2017}, pages={400–417} }
 @article{zhang_pinnix_zhang_miller_rufty_2017, title={Evaluation of Key Methodology for Digital Image Analysis of Turfgrass Color Using Open-Source Software}, volume={57}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2016.04.0285}, abstractNote={Digital image analysis is a frequently used research technique to provide an objective measure of turfgrass color, in addition to the traditional visual rating. A commonly used method relies on commercial software package SigmaScan Pro to quantify mean hue angle, saturation, and brightness values from turf images, and to calculate a dark green color index as the measure of color. To enable turf image analysis to function on an open‐source platform, a method was developed within ImageJ to batch process turf images for color parameters. This Java‐based ImageJ plugin quantifies hue angle, saturation, and brightness values and calculates a dark green color index. In addition, information on the variability of these color parameters can be simultaneously acquired. This new method was used to quantify color parameters of turf images collected from field plots of tall fescue (Schedonorus arundinacea Shreb. Dumort.), Kentucky bluegrass (Poa pratensis L.), ryegrass (Lolium ssp.), hybrid bermudagrass (Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt‐Davy), and creeping bentgrass (Agrostis stolonifera L.). While color parameter values differed little between ImageJ and SigmaScan, the time saved in processing images using ImageJ was considerable. Aside from software, analysis of color parameters acquired from the five turfgrass species indicated that hue angle alone can adequately measure turf color in digital images. Results also demonstrated that, in addition to light source, camera settings should remain fixed during photo capture to avoid introducing errors. The ImageJ plug‐in developed in this study is made available at www.turffiles.ncsu.edu.}, number={2}, journal={CROP SCIENCE}, author={Zhang, Chenxi and Pinnix, Garland D. and Zhang, Zheng and Miller, Grady L. and Rufty, Thomas W.}, year={2017}, pages={550–558} }
 @article{manandhar_sinclair_rufty_ghanem_2017, title={Leaf Expansion and Transpiration Response to Soil Drying and Recovery among Cowpea Genotypes}, volume={57}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2016.09.0794}, abstractNote={Sensitivity of leaf expansion to water‐deficit conditions could have a major influence on C assimilation rate and water loss rate under developing drought conditions. While cowpea (Vigna unguiculata L.) is commonly grown in more arid regions, there is no information on the sensitivity of its leaf expansion with drying soil. Three experiments were undertaken in controlled environments to document leaf expansion during increasing soil drying (11–13 d). Eight cultivars of cowpea were studied. It was found that the initiation of the decrease in leaf expansion occurred earlier in the soil drying cycle than the decrease in transpiration rate in all genotypes. Also, the soil water content at which leaf expansion completely stopped was slightly greater than the termination of transpiration. Therefore, both measures of leaf expansion sensitivity to soil water showed greater sensitivity to soil drying than plant gas exchange as measured by transpiration rate. Genotypic differences were observed among the genotypes in their sensitivity to soil drying. In one experiment, the severely stressed plants were rewatered and recovery in leaf expansion rate occurred very rapidly. Leaf expansion rates of all genotypes following rewatering returned to the rates of the well‐watered plants within ∼1 d.}, number={4}, journal={CROP SCIENCE}, author={Manandhar, Anju and Sinclair, Thomas R. and Rufty, Thomas W. and Ghanem, Michel E.}, year={2017}, pages={2109–2116} }
 @article{manandhar_sinclair_rufty_ghanem_2017, title={Leaf emergence (phyllochron index) and leaf expansion response to soil drying in cowpea genotypes}, volume={160}, ISSN={["1399-3054"]}, DOI={10.1111/ppl.12544}, abstractNote={Drought can result in severely decreased leaf area development, which impacts plant growth and yield. However, rarely is leaf emergence or leaf expansion separated to resolve the relative sensitivity to water‐deficit of these two processes. Experiments were undertaken to impose drought over approximately 2 weeks for eight cowpea (Vigna unguiculata) genotypes grown in pots under controlled environmental conditions. Daily measures of phyllochron index (PI, leaf emergence) and leaf area increase (leaf expansion) were obtained. Each of these measures was referenced against volumetric soil water content, i.e. fraction transpirable soil water. Although there was no clear difference between leaf emergence and leaf expansion in sensitivity to drying soil, both processes were more sensitive to soil drying than plant transpiration rate. Genotypic differences in the soil water content at the initiation of the decline in PI were identified. However, no consistent difference in sensitivity to water‐deficit in leaf expansion was found. The difference in leaf emergence among genotypes in sensitivity to soil drying can now be exploited to provide guidance for plant improvement and crop yield increase.}, number={2}, journal={PHYSIOLOGIA PLANTARUM}, author={Manandhar, Anju and Sinclair, Thomas R. and Rufty, Thomas W. and Ghanem, Michel E.}, year={2017}, month={Jun}, pages={201–208} }
 @misc{sinclair_devi_shekoofa_choudhary_sadok_vadez_riar_rufty_2017, title={Limited-transpiration response to high vapor pressure deficit in crop species}, volume={260}, ISSN={["1873-2259"]}, DOI={10.1016/j.plantsci.2017.04.007}, abstractNote={Water deficit under nearly all field conditions is the major constraint on plant yields. Other than empirical observations, very little progress has been made in developing crop plants in which specific physiological traits for drought are expressed. As a consequence, there was little known about under what conditions and to what extent drought impacts crop yield. However, there has been rapid progress in recent years in understanding and developing a limited-transpiration trait under elevated atmospheric vapor pressure deficit to increase plant growth and yield under water-deficit conditions. This review paper examines the physiological basis for the limited-transpiration trait as result of low plant hydraulic conductivity, which appears to be related to aquaporin activity. Methodology was developed based on aquaporin involvement to identify candidate genotypes for drought tolerance of several major crop species. Cultivars of maize and soybean are now being marketed specifically for arid conditions. Understanding the mechanism of the limited-transpiration trait has allowed a geospatial analyses to define the environments in which increased yield responses can be expected. This review highlights the challenges and approaches to finally develop physiological traits contributing directly to plant improvement for water-limited environments.}, journal={PLANT SCIENCE}, author={Sinclair, Thomas R. and Devi, Jyostna and Shekoofa, Avat and Choudhary, Sunita and Sadok, Walid and Vadez, Vincent and Riar, Mandeep and Rufty, Thomas}, year={2017}, month={Jul}, pages={109–118} }
 @article{sinclair_manandhar_shekoofa_rosas-anderson_bagherzadi_schoppach_sadok_rufty_2017, title={Pot binding as a variable confounding plant phenotype: theoretical derivation and experimental observations}, volume={245}, ISSN={["1432-2048"]}, DOI={10.1007/s00425-016-2641-0}, abstractNote={Theoretical derivation predicted growth retardation due to pot water limitations, i.e., pot binding. Experimental observations were consistent with these limitations. Combined, these results indicate a need for caution in high-throughput screening and phenotyping. Pot experiments are a mainstay in many plant studies, including the current emphasis on developing high-throughput, phenotyping systems. Pot studies can be vulnerable to decreased physiological activity of the plants particularly when pot volume is small, i.e., "pot binding". It is necessary to understand the conditions under which pot binding may exist to avoid the confounding influence of pot binding in interpreting experimental results. In this paper, a derivation is offered that gives well-defined conditions for the occurrence of pot binding based on restricted water availability. These results showed that not only are pot volume and plant size important variables, but the potting media is critical. Artificial potting mixtures used in many studies, including many high-throughput phenotyping systems, are particularly susceptible to the confounding influences of pot binding. Experimental studies for several crop species are presented that clearly show the existence of thresholds of plant leaf area at which various pot sizes and potting media result in the induction of pot binding even though there may be no immediate, visual plant symptoms. The derivation and experimental results showed that pot binding can readily occur in plant experiments if care is not given to have sufficiently large pots, suitable potting media, and maintenance of pot water status. Clear guidelines are provided for avoiding the confounding effects of water-limited pot binding in studying plant phenotype.}, number={4}, journal={PLANTA}, author={Sinclair, Thomas R. and Manandhar, Anju and Shekoofa, Avat and Rosas-Anderson, Pablo and Bagherzadi, Laleh and Schoppach, Remy and Sadok, Walid and Rufty, Thomas W.}, year={2017}, month={Apr}, pages={729–735} }
 @article{sermons_wherley_zhang_bowman_rufty_2017, title={The role of internal and external nitrogen pools in bermudagrass growth during spring emergence from dormancy}, volume={40}, ISSN={["1532-4087"]}, DOI={10.1080/01904167.2016.1264424}, abstractNote={ABSTRACT As bermudagrass (Cynodon dactylon (L.) Pers.) transitions from winter dormancy to active growth in spring, nitrogen is essential for new tissue growth. We examined the relative contributions of internally stored nitrogen and that taken up by preexisting and newly produced roots. Field-collected dormant bermudagrass was transferred to a nutrient solution culture system in a growth chamber. Cultures were provided either a non-nitrogen-containing solution or one amended with nitrate labeled with the 15N isotope of nitrogen, which allowed tracking of endogenous and exogenous N pools in all tissues as growth began. Nitrogen in stolon internodes was the largest N source for early growth. Though mass increased at the same rate in both N treatments over 3 weeks of growth, the unfertilized treatment showed early signs of nitrogen deficiency: low tissue N, slowed leaf elongation, and fewer but longer roots. Preexisting roots were active in absorption almost immediately; new roots were produced quickly and had even higher N uptake rates.}, number={10}, journal={JOURNAL OF PLANT NUTRITION}, author={Sermons, Shannon M. and Wherley, Benjamin G. and Zhang, Chenxi and Bowman, Daniel C. and Rufty, Thomas W.}, year={2017}, pages={1404–1416} }
 @article{reynolds_miller_livingston_rufty_2016, title={Athletic Field Paint Color Impacts Transpiration and Canopy Temperature in Bermudagrass}, volume={56}, ISSN={0011-183X}, url={http://dx.doi.org/10.2135/cropsci2016.01.0028}, DOI={10.2135/cropsci2016.01.0028}, abstractNote={Athletic field paints have varying impacts on turfgrass health that have been linked to their ability to alter photosynthetically active radiation and photosynthesis on the basis of color. It was further hypothesized they may also alter transpiration and canopy temperature by disrupting gas exchange at the leaf surface. Growth chamber experiments evaluated the effects of air temperature and six colors of paint on daily water loss and canopy temperature in ‘Tifway’ bermudagrass [Cynodon dactylon (L.) Pers. x C. transvaalensis Burtt‐Davy]. Daily water loss and canopy temperature were measured every 24 h using gravimetric techniques and an infrared digital thermometer, while lab experiments examined the thickness of white and black paint on the leaf surface. In nonpainted bermudagrass canopies, daily water loss increased (P ≤ 0.0001) with canopy temperature from 29 to 36°C, while in painted bermudagrass canopies it decreased (P ≤ 0.0001) as canopy temperature increased from 29 to 40°C. Yellow and white paint impacted transpiration and canopy temperature the least, while black and blue caused the greatest reductions in transpiration and highest increases in canopy temperature. Cross‐sections of painted Tifway indicate that paint may limit evaporative cooling by clogging stomata. Increased absorption of radiant energy by paint coupled with limited evaporative cooling result in increased heat stress and decreased turfgrass performance in painted canopies.}, number={4}, journal={Crop Science}, publisher={Crop Science Society of America}, author={Reynolds, William Casey and Miller, Grady L. and Livingston, David P. and Rufty, Thomas W.}, year={2016}, pages={2016} }
 @article{riar_carley_zhang_schroeder-moreno_jordan_webster_rufty_2016, title={Environmental Influences on Growth and Reproduction of Invasive Commelina benghalensis}, volume={2016}, ISSN={1687-8159 1687-8167}, url={http://dx.doi.org/10.1155/2016/5679249}, DOI={10.1155/2016/5679249}, abstractNote={Commelina benghalensis(Benghal dayflower) is a noxious weed that is invading agricultural systems in the southeastern United States. We investigated the influences of nutrition, light, and photoperiod on growth and reproductive output ofC. benghalensis. In the first experimental series, plants were grown under high or low soil nutrition combined with either full light or simulated shade. Lowered nutrition strongly inhibited vegetative growth and aboveground spathe production. Similar but smaller effects were exerted by a 50% reduction in light, simulating conditions within a developing canopy. In the second series of experiments,C. benghalensisplants were exposed to different photoperiod conditions that produced short- and long-day plants growing in similar photosynthetic periods. A short-day photoperiod decreased time to flowering by several days and led to a 40 to 60% reduction in vegetative growth, but reproduction above and below ground was unchanged. Collectively, the results indicate that (1) fertility management in highly weathered soils may strongly constrain competitiveness ofC. benghalensis; (2) shorter photoperiods will limit vegetative competitiveness later in the growing seasons of most crops; and (3) the high degree of reproductive plasticity and output possessed byC. benghalensiswill likely cause continual persistence problems in agricultural fields.}, journal={International Journal of Agronomy}, publisher={Hindawi Limited}, author={Riar, Mandeep K. and Carley, Danesha S. and Zhang, Chenxi and Schroeder-Moreno, Michelle S. and Jordan, David L. and Webster, Theodore M. and Rufty, Thomas W.}, year={2016}, pages={1–9} }
 @article{shekoofa_rosas-anderson_carley_sinclair_rufty_2016, title={Limited transpiration under high vapor pressure deficits of creeping bentgrass by application of Daconil-Action (R)}, volume={243}, ISSN={["1432-2048"]}, DOI={10.1007/s00425-015-2417-y}, abstractNote={First observation that chemical spray can induce limited-transpiration rate under high vapor pressure deficit. It appears that acibenzolar may be key in inducing this water conservation trait. Irrigation and water use have become major issues in management of turfgrasses. Plant health products that have been introduced into the turfgrass market have been observed to improve plant performance in water stress conditions. In this study, we evaluated whether a selection of common plant health products alter the ability of creeping bentgrass (Agrostis stolonifera L.) to control transpiration under high vapor pressure deficit (VPD). The plant health treatments--Daconil Action, Insignia, and Signature--were applied to plots on golf course putting greens located in Raleigh NC and in Scottsdale, AZ. Using intact cores removed from the putting greens, transpiration rates were measured over a range of VPDs in controlled conditions. In all cases stretching over a 3-year period, bentgrass cores from field plots treated with Daconil-Action limited transpiration under high VPD conditions, while check treatments with water, and others treated with Insignia or Signature did not. Transpiration control became engaged when VPDs reached values ranging from 1.39 to 2.50 kPa, and was not strongly influenced by the field temperature at which the bentgrass was growing. Because all plots in NC had been treated with chlorothalonil-the key ingredient in Daconil Action to control diseases-it was concluded that the likely chemical ingredient in Daconil Action triggering the transpiration control response was acibenzolar. This is the first evidence that the limited-transpiration trait can be induced by a chemical application, and it implies significant potential for ameliorating drought vulnerability in cool-season turfgrasses, and likely other plant species.}, number={2}, journal={PLANTA}, author={Shekoofa, Avat and Rosas-Anderson, Pablo and Carley, Danesha S. and Sinclair, Thomas R. and Rufty, Thomas W.}, year={2016}, month={Feb}, pages={421–427} }
 @article{lu_bowman_rufty_shi_2015, title={Reactive Nitrogen in Turfgrass Systems: Relations to Soil Physical, Chemical, and Biological Properties}, volume={44}, ISSN={["1537-2537"]}, DOI={10.2134/jeq2014.06.0247}, abstractNote={Turfgrass systems contribute to the loading of reactive N to water and air via runoff, leaching, and gas emission. Yet, a comprehensive approach has never been developed to assess N loss potential from turfgrass systems. We used pools and production of reactive N (inorganic N, extractable organic N, and NO) to estimate N loss potential and hypothesized that this potential could be predicated by basic soil properties. A total of 68 soil samples were taken from 17 bermudagrass sites in North Carolina. Basic soil properties were analyzed, including soil C and N, C:N ratio, microbial biomass, moisture, pH, and percent silt/clay/sand. Soil samples varied most widely in texture, followed by soil C and N, microbial biomass, moisture, pH, and C:N ratio. The pools of extractable organic N and inorganic N were comparable, indicating that soluble organic N should be considered as a pathway of N loss from turfgrass. Turfgrass with large pools and production of reactive N was characterized by high soil C and N, microbial biomass, and moisture. Because soil C and N accumulate over time after turfgrass establishment, turfgrass age could be a suitable practical indicator of N loss potential and thus could be used to implement changes in management. Pools and production of reactive N in liquid and gas phases were well correlated, suggesting that if a turfgrass system has a high potential of N loss via leaching and runoff, it may also be of a high potential for NO emissions.}, number={1}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Lu, Caiyan and Bowman, Daniel and Rufty, Thomas and Shi, Wei}, year={2015}, pages={210–218} }
 @article{rosas-anderson_sinclair_balota_tallury_isleib_rufty_2014, title={Genetic Variation for Epidermal Conductance in Peanut}, volume={54}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2013.07.0461}, abstractNote={ABSTRACT}, number={2}, journal={CROP SCIENCE}, author={Rosas-Anderson, Pablo and Sinclair, Thomas R. and Balota, Maria and Tallury, Shyam and Isleib, Thomas G. and Rufty, Thomas}, year={2014}, pages={730–737} }
 @article{rosas-anderson_shekoofa_sinclair_balota_isleib_tallury_rufty_2014, title={Genetic variation in peanut leaf maintenance and transpiration recovery from severe soil drying}, volume={158}, ISSN={0378-4290}, url={http://dx.doi.org/10.1016/J.FCR.2013.12.019}, DOI={10.1016/J.FCR.2013.12.019}, abstractNote={Peanut (Arachis hypogaea L.) is an important food crop that is often grown in areas prone to intermittent drought. After drought is relieved, plant recovery from soil drying is an important factor for continued productivity. While recovery can involve a multitude of physiological processes, transpiration is one of the most important for carbon fixation. Two greenhouse experiments and a field experiment were conducted to screen and evaluate a total of 19 peanut genotypes for transpiration recovery and leaf maintenance after experiencing a drying cycle. In the greenhouse experiments, plants were allowed to transpire all available transpirable soil water from their pots before being re-watered. The transpiration of plants was measured in subsequent days and a visual rating scale was used to rate leaf maintenance on plants. Significant differences were detected among genotypes for both transpiration recovery and leaf maintenance, and superior genotypes were identified for both traits. The superior genotypes included ICGV 86015, TMV 2, PI 497579 and PI 404020 in the greenhouse. In the field, a regression between stomatal conductance before and after re-watering gave an estimate for recovery of stomatal conductance. Breeding lines N05006 and SPT 06-07 had the greatest estimated stomata conductance recovery in the field. Genotypes which recovered poorly in the greenhouse also had low estimated recovery in the field.}, journal={Field Crops Research}, publisher={Elsevier BV}, author={Rosas-Anderson, Pablo and Shekoofa, Avat and Sinclair, Thomas R. and Balota, Maria and Isleib, Thomas G. and Tallury, Shyam and Rufty, Thomas}, year={2014}, month={Mar}, pages={65–72} }
 @article{riar_spears_burns_jordan_zhang_rufty_2014, title={Persistence of Benghal dayflower (Commelina benghalensis) in sustainable agronomic systems: Potential impacts of hay bale storage, animal digestion, and cultivation}, volume={38}, DOI={10.1080/21683565.2013.839486}, abstractNote={Experiments were conducted to evaluate factors affecting persistence of the invasive, federal noxious weed Benghal dayflower in sustainable agronomic systems. Seeds were exposed to a range of temperatures simulating those found in hay bales in the field and periodically tested for viability over 21 days. Seeds were nonviable after one day at 65 °C and after 14 days at 50 or 45 °C. A second series of experiments examined the effects of simulated rumen digestion on germination and viability of Benghal dayflower seeds and the response was compared to that with seeds of five other common weed species. Time courses revealed that seeds from the other weeds were acutely damaged by digestion and viability depressed after 48 and 96 h, but germination of Benghal dayflower seeds was increased at 48 h, and only a slight decrease occurred after 96 h. In the third experimental series, stem fragments of Benghal dayflower were buried in soil at 2 and 6 cm depths and exposed to aerial temperatures of 20, 25, 30, and 35 °C for 30 days. Root development occurred at both depths, but leaf development was restricted at 6 cm and subterranean spathe development was not found at 2 cm. Temperatures higher than 25 °C favor regeneration at both depths. The results, collectively, show the difficulty encountered when trying to control or eradicate Benghal dayflower in sustainable farming systems. Farms must avoid using fresh hay as animal feed when Benghal dayflower is present in hay fields, as little restraint on seed viability will be exerted during digestion and generation of manure. Cultivation is unlikely to be an effective control strategy during summer months when Benghal dayflower is growing most aggressively, because soil temperatures are optimal for vegetative regeneration.}, number={3}, journal={Agroecology and Sustainable Food Systems}, author={Riar, M. K. and Spears, J. F. and Burns, J. C. and Jordan, D. L. and Zhang, C. X. and Rufty, T. W.}, year={2014}, pages={283–298} }
 @article{seversike_sermons_sinclair_carter_rufty_2014, title={Physiological properties of a drought-resistant wild soybean genotype: Transpiration control with soil drying and expression of root morphology}, volume={374}, ISSN={["1573-5036"]}, DOI={10.1007/s11104-013-1757-2}, number={1-2}, journal={PLANT AND SOIL}, author={Seversike, Thomas M. and Sermons, Shannon M. and Sinclair, Thomas R. and Carter, Thomas E., Jr. and Rufty, Thomas W.}, year={2014}, month={Jan}, pages={359–370} }
 @article{abdel-haleem_carter_rufty_boerma_li_2014, title={Quantitative trait loci controlling aluminum tolerance in soybean: candidate gene and single nucleotide polymorphism marker discovery}, volume={33}, ISSN={["1572-9788"]}, DOI={10.1007/s11032-013-9999-5}, number={4}, journal={MOLECULAR BREEDING}, author={Abdel-Haleem, Hussein and Carter, Thomas E., Jr. and Rufty, Thomas W. and Boerma, H. Roger and Li, Zenglu}, year={2014}, month={Apr}, pages={851–862} }
 @article{cheng_booker_burkey_tu_shew_rufty_fiscus_deforest_hu_2014, title={Soil microbial responses to elevated CO2 and O-3 in a nitrogen-aggrading agroecosystem}, DOI={10.1201/b16845-14}, journal={Carbon Capture and Storage: CO2 Management Technologies}, author={Cheng, L. and Booker, F. L. and Burkey, K. O. and Tu, C. and Shew, H. D. and Rufty, T. W. and Fiscus, E. L. and Deforest, J. L. and Hu, Shuijin}, year={2014}, pages={277–307} }
 @article{jeffries_gannon_rufty_yelverton_2013, title={Effect of Selective Amicarbazone Placement on Annual Bluegrass (Poa annua) and Creeping Bentgrass Growth}, volume={27}, ISSN={["0890-037X"]}, DOI={10.1614/wt-d-13-00015.1}, abstractNote={Growth chamber experiments were conducted to assess the effects of foliage-only, soil-only, and foliage-plus-soil placements of amicarbazone on annual bluegrass and creeping bentgrass growth. Evaluated herbicide treatments included amicarbazone at 49 or 147 g ai ha−1, as well as bispyribac-sodium at 74 g ai ha−1for comparative purposes. Data from this research agree with previous reports of amicarbazone plant uptake. Amicarbazone is absorbed via above- and belowground pathways; however, plant growth is inhibited more by root uptake. Compared to foliage-only amicarbazone placement, soil-only placement more than doubled reductions in aboveground biomass and root mass 56 d after treatment (DAT), whereas no differences were detected between placements including soil contact. Across all evaluated parameters in this research, amicarbazone (49 g ha−1) impacted creeping bentgrass growth similarly to bispyribac-sodium, whereas annual bluegrass growth was inhibited more by amicarbazone, suggesting it provides a more efficacious chemical option for end-user applications.}, number={4}, journal={WEED TECHNOLOGY}, author={Jeffries, Matthew D. and Gannon, Travis W. and Rufty, Thomas W. and Yelverton, Fred H.}, year={2013}, pages={718–724} }
 @article{zhang_miller_rufty_bowman_2013, title={Nitrate Leaching from Two Kentucky Bluegrass Cultivars as Affected by Nitrate Uptake Capacity and Subsurface Soil Compaction}, volume={53}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2012.10.0600}, abstractNote={ABSTRACT}, number={4}, journal={CROP SCIENCE}, author={Zhang, Chenxi and Miller, Grady L. and Rufty, Thomas W. and Bowman, Daniel C.}, year={2013}, pages={1722–1733} }
 @article{zhang_rufty_miller_bowman_2013, title={Nitrate Uptake Rates of Kentucky Bluegrass Genotypes and Their Effect on Nitrate Absorption under Competitive Conditions}, volume={53}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2012.10.0597}, abstractNote={ABSTRACT}, number={3}, journal={CROP SCIENCE}, author={Zhang, Chenxi and Rufty, Thomas W. and Miller, Grady L. and Bowman, Daniel C.}, year={2013}, month={May}, pages={1179–1188} }
 @article{gannon_hixson_weber_shi_yelverton_rufty_2013, title={Sorption of Simazine and S-Metolachlor to Soils from a Chronosequence of Turfgrass Systems}, volume={61}, ISSN={["1550-2759"]}, DOI={10.1614/ws-d-12-00173.1}, abstractNote={Pesticide sorption by soil is among the most sensitive input parameters in many pesticide-leaching models. For many pesticides, organic matter is the most important soil constituent influencing pesticide sorption. Increased fertility, irrigation, and mowing associated with highly maintained turfgrass areas result in constant deposition of organic material, creating a soil system that can change drastically with time. Changes in soil characteristics could affect the environmental fate of pesticides applied to turfgrass systems of varying ages. Sorption characteristics of simazine andS-metolachlor were determined on five soils from bermudagrass systems of increasing ages (1, 4, 10, 21, and 99 yr) and compared to adjacent native pine and bare-ground areas. Surface soil (0 to 5 cm) and subsurface soil (5 to 15 cm) from all sites were air-dried and passed through a 4-mm sieve for separation from plant material. Using a batch-equilibrium method, sorption isotherms were determined for each soil. Data were fit to the Freundlich equation, andKd(soil sorption coefficient) andKoc(organic carbon sorption coefficient) values were determined. Sorption and soil system age were directly related to organic matter content in the soil. Sorption of both herbicides increased with age of the soil system and was greatest on the surface soil from the oldest bermudagrass soil system. Herbicide sorption decreased at greater soil depths with lower organic matter. Greater amount of14C–simazine sorbed to subsurface soil of the oldest turfgrass system compared to14C–S-metolachlor. Results indicate that as bermudagrass systems age and accumulate higher organic matter levels increased herbicide sorption may decrease the leaching potential and bioavailability of simazine andS-metolachlor.}, number={3}, journal={WEED SCIENCE}, author={Gannon, Travis W. and Hixson, Adam C. and Weber, Jerome B. and Shi, Wei and Yelverton, Fred H. and Rufty, Thomas W.}, year={2013}, pages={508–514} }
 @article{seversike_sermons_sinclair_carter_rufty_2013, title={Temperature interactions with transpiration response to vapor pressure deficit among cultivated and wild soybean genotypes}, volume={148}, ISSN={["1399-3054"]}, DOI={10.1111/j.1399-3054.2012.01693.x}, abstractNote={A key strategy in soybean drought research is increased stomatal sensitivity to high vapor pressure deficit (VPD), which contributes to the ‘slow wilting’ trait observed in the field. These experiments examined whether temperature of the growth environment affected the ability of plants to respond to VPD, and thus control transpiration rate (TR). Two soybean [Glycine max (L.) Merr.] and four wild soybean [Glycine soja (Sieb. and Zucc.)] genotypes were studied. The TR was measured over a range of VPD when plants were growing at 25 or 30°C, and again after an abrupt increase of 5°C. In G. max, a restriction of TR became evident as VPD increased above 2.0 kPa when temperature was near its growth optimum of 30°C. ‘Slow wilting’ genotype plant introduction (PI) 416937 exhibited greater TR control at high VPD compared with Hutcheson, and only PI 416937 restrained TR after the shift to 35°C. Three of the four G. soja genotypes exhibited control over TR with increasing VPD when grown at 25°C, which is near their estimated growth optimum. The TR control became engaged at lower VPD than in G. max and was retained to differing degrees after a shift to 30°C. The TR control systems in G. max and G. soja clearly were temperature‐sensitive and kinetically definable, and more restrictive in the ‘slow wilting’ soybean genotype. For the favorable TR control traits observed in G. soja to be useful for soybean breeding in warmer climates, the regulatory linkage with lower temperatures must be uncoupled.}, number={1}, journal={PHYSIOLOGIA PLANTARUM}, author={Seversike, Thomas M. and Sermons, Shannon M. and Sinclair, Thomas R. and Carter, Thomas E., Jr. and Rufty, Thomas W.}, year={2013}, month={May}, pages={62–73} }
 @article{reynolds_miller_rufty_2012, title={Athletic Field Paint Impacts Light Spectral Quality and Turfgrass Photosynthesis}, volume={52}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci2012.01.0059}, abstractNote={ABSTRACT}, number={5}, journal={CROP SCIENCE}, author={Reynolds, William Casey and Miller, Grady L. and Rufty, Thomas W.}, year={2012}, month={Sep}, pages={2375–2384} }
 @article{riar_webster_brecke_jordan_burton_telenko_rufty_2012, title={Benghal Dayflower (Commelina benghalensis) Seed Viability in Soil}, volume={60}, ISSN={["0043-1745"]}, DOI={10.1614/ws-d-12-00047.1}, abstractNote={Benghal dayflower is an exotic weed species in the United States that is a challenge to manage in agricultural fields. Research was conducted in North Carolina, Georgia, and Florida to evaluate the longevity of buried Benghal dayflower seeds. Seeds were buried in the field for 2 to 60 mo at a depth of 20 cm in mesh bags containing soil native to each area. In North Carolina, decline of Benghal dayflower seed viability was described by a sigmoidal regression model, with seed size having no effect on viability. Seed viability at the initiation of the study was 81%. After burial, viability declined to 51% after 24 mo, 27% after 36 mo, and < 1% after 42 mo. In Georgia, initial seed viability averaged 86% and declined to 63 and 33% at 12 and 24 mo, respectively. Burial of 36 mo or longer reduced seed viability to < 2%. The relationship between Benghal dayflower seed viability and burial time was described by a sigmoidal regression model. In Florida, there was greater variability in Benghal dayflower seed viability than there was at the other locations. Seed viability at the first sampling date after 2 mo of burial was 63%. Although there were fluctuations during the first 24 mo, the regression model indicated approximately 60% of seed remained viable. After 34 mo of burial, seed viability was reduced to 46% and then rapidly fell to 7% at 39 mo, which was consistent with the decrease in seed viability at the other locations. Although there is a physical dormancy imposed by the seed coat of Benghal dayflower, which has been detected in previous studies, it appears that a decline in buried seed viability to minimal levels occurs within 39 to 48 mo in the southeastern United States, suggesting that management programs must prevent seed production for at least four growing seasons to severely reduce the Benghal dayflower soil seedbank.}, number={4}, journal={WEED SCIENCE}, author={Riar, Mandeep K. and Webster, Theodore M. and Brecke, Barry J. and Jordan, David L. and Burton, Michael G. and Telenko, Darcy P. and Rufty, Thomas W.}, year={2012}, pages={589–592} }
 @article{dell_carley_rufty_shi_2012, title={Heat stress and N fertilization affect soil microbial and enzyme activities in the creeping bentgrass (Agrostis Stolonifera L.) rhizosphere}, volume={56}, ISSN={0929-1393}, url={http://dx.doi.org/10.1016/j.apsoil.2012.02.002}, DOI={10.1016/j.apsoil.2012.02.002}, abstractNote={High summer temperatures often cause damage to bentgrass on putting greens in transition zone regions. One of the most damaging effects is a depression of rooting. Although heat stress effects on plant functions are considered as a main reason for the damage, heat stress also may be related to organic matter (OM) accumulation and poor gas exchange into the rhizosphere. The OM accumulation and the often-observed root dieback suggest that soil microbial processes play a role in summer bentgrass decline. In this study, the impact of high temperature on soil microbial properties and enzyme activities was examined using creeping bentgrass (Agrostis stolonifera) growing in a phytotron controlled environment chamber. The high temperature exposures (34/30 °C versus 22/18 °C for controls) lasted for four weeks and the bentgrass cultures received mineral N at two rates. Our working hypothesis was that not only did high temperatures stimulate overall soil microbial and enzyme activity but also selectively modified microbial catabolic functions. To test this hypothesis, we compared temperature sensitivities and Q10 values of microbial substrate utilization patterns using a Biolog plate approach and soil enzyme activities. The results indicated that soil enzyme activities had similar responses to assay temperatures and their Q10 values averaged ∼2 with changes of laboratory assay temperatures from 12 to 22 °C and from 22 to 34 °C. Such positive responses of microbial activity to high temperatures were supported by parallel increases in rates of microbial substrate utilization. Total substrate availability in Biolog plates also increased with laboratory assay temperatures. This enhancement could not be explained by the overall stimulation of high temperature on microbial activity, but instead by selective modification of microbial community functions. Nitrogen fertilization significantly changed soil biological activities. Phenol oxidase activity was reduced by the high rate of N fertilization, whereas β-glucosidase and β-glucosaminidase activities were increased. Interactions on soil enzyme activities between growth chamber temperatures and N fertilization rates also occurred. Soil peroxidase activity was ∼three-fold greater for bentgrass subjected to heat stress and the low rate of N fertilization. Our results indicated that summer heat stress and the associated increases in root and OM degradation in bentgrass systems are related with overall temperature stimulations on soil microbial and enzyme activities as well as with modifications in functional components of the microbial community.}, journal={Applied Soil Ecology}, publisher={Elsevier BV}, author={Dell, Emily A. and Carley, Danesha Seth and Rufty, Thomas and Shi, Wei}, year={2012}, month={May}, pages={19–26} }
 @article{schroeder-moreno_greaver_wang_hu_rufty_2012, title={Mycorrhizal-mediated nitrogen acquisition in switchgrass under elevated temperatures and N enrichment}, volume={4}, ISSN={["1757-1707"]}, DOI={10.1111/j.1757-1707.2011.01128.x}, abstractNote={Abstract}, number={3}, journal={GLOBAL CHANGE BIOLOGY BIOENERGY}, author={Schroeder-Moreno, Michelle S. and Greaver, Tara L. and Wang, Shuxin and Hu, Shujin and Rufty, Thomas W.}, year={2012}, month={May}, pages={266–276} }
 @article{sinclair_rufty_2012, title={Nitrogen and water resources commonly limit crop yield increases, not necessarily plant genetics}, volume={1}, ISSN={2211-9124}, url={http://dx.doi.org/10.1016/j.gfs.2012.07.001}, DOI={10.1016/j.gfs.2012.07.001}, abstractNote={Frequently, improved plant genetics is viewed as the path to increased crop yields. However, in this manuscript, we argue that yield increases most often result from a combination of improved genetics and increased availability of nitrogen and water resources. At this time, it is likely that resource availability is the main impediment to yield increase in many cropping systems. In developing regions, it appears that nitrogen availability limits crop yield. In developed regions, rainfall and water availability commonly impose a substantial constraint on further crop yield increase. Strategies are examined to enhance resource accumulation and use in cropping systems of the future.}, number={2}, journal={Global Food Security}, publisher={Elsevier BV}, author={Sinclair, Thomas R. and Rufty, Thomas W.}, year={2012}, month={Dec}, pages={94–98} }
 @article{sermons_seversike_sinclair_fiscus_rufty_2012, title={Temperature influences the ability of tall fescue to control transpiration in response to atmospheric vapour pressure deficit}, volume={39}, ISSN={1445-4408}, url={http://dx.doi.org/10.1071/FP12172}, DOI={10.1071/FP12172}, abstractNote={Water availability for turfgrass systems is often limited and is likely to become more so in the future. Here, we conducted experiments that examined the ability of tall fescue (Festuca arundinacea Schreb.) to control transpiration with increasing vapour pressure deficit (VPD) and determined whether control was influenced by temperature. The first study was under steady-state conditions at two temperatures (21 and 27°C) and two VPDs (1.2 and 1.8 kPa). At the lower temperature, water use was similar at both VPDs, indicating a restriction of transpiration at high VPD. At 27°C, transpiration control at high VPD was weakened and root growth also declined; both responses increase susceptibility to water-deficit stress. Another series of experiments was used to examine the physiological stability of the transpiration control. Temperature and VPD were adjusted in a stepwise manner and transpiration measured across a range of VPD in the days following environmental shifts. Results indicated that VPD control acclimated to the growth environment, with adjustment to drier conditions becoming evident after ~1 week. Control was again more effective at cool than at hot temperatures. Collectively, the results indicate that transpiration control by this cool season grass is most effective in the temperature range where it is best adapted.}, number={12}, journal={Functional Plant Biology}, publisher={CSIRO Publishing}, author={Sermons, Shannon M. and Seversike, Thomas M. and Sinclair, Thomas R. and Fiscus, Edwin L. and Rufty, Thomas W.}, year={2012}, pages={979} }
 @article{wherley_bowman_shi_rufty_2011, title={Effect of Soil Saturation on Development and 15N-Nitrate Uptake Efficiency of two warm season efficiency of two warm season grasses emerging from dormancy}, volume={34}, ISSN={0190-4167 1532-4087}, url={http://dx.doi.org/10.1080/01904167.2011.610489}, DOI={10.1080/01904167.2011.610489}, abstractNote={Use of effluent on turfgrass is increasing due to population growth and limited water supplies. Because effluent is generated continuously, turf managers may be forced to over-irrigate, leading to soil saturation. Although the nutrients in effluent are readily absorbed by turf, the effects of prolonged soil saturation on uptake are unknown. This research examined the impact of soil saturation on plant development and nitrate uptake of two warm-season turfgrasses emerging from dormancy. Dormant grass/soil cores of hybrid bermudagrass and common centipedegrass were treated to stimulate regrowth, with soil moisture controlled at saturation (∼0.36 cm3 cm−3) or field capacity (0.13 cm3 cm−3). Soil saturation reduced canopy development in both species, but shoot biomass was affected only in bermudagrass. Nitrate uptake by both species was generally unaffected by soil saturation. While extended periods of soil saturation may alter plant development, they do not impair the ability of these turfgrasses to absorb nitrogen.}, number={13}, journal={Journal of Plant Nutrition}, publisher={Informa UK Limited}, author={Wherley, Benjamin and Bowman, Daniel and Shi, Wei and Rufty, Thomas, Jr.}, year={2011}, month={Oct}, pages={2039–2054} }
 @article{liu_dell_yao_rufty_shi_2011, title={Microbial and soil properties in bentgrass putting greens: Impacts of nitrogen fertilization rates}, volume={162}, ISSN={["1872-6259"]}, DOI={10.1016/j.geoderma.2011.02.009}, abstractNote={Nitrogen fertilization is important for maintaining the quality of golf course putting greens, but causes environmental concerns and affects soil organic matter buildup. Belowground biology and processes are vital to address both environmental and organic buildup issues. We examined microbial and soil properties in sand-based bentgrass putting greens that had been unfertilized or fertilized at the rates of 195, 244, and 305 kg N ha−1 yr−1 for over one year after turf establishment. Nitrogen fertilization increased soil organic C by ~ 10% and slightly modified microbial community as revealed by denaturing gradient gel electrophoresis, but had no effects on microbial biomass or C and N mineralization. We observed that changes in soil pH and enzyme activities were the functions of fertilization rates. Soil pH was reduced by ~ 0.3 to 0.8 units as fertilization rates increased. The activities of soil enzymes (β-glucosidase, N-acetyl-β-glucosaminidase, chitinase, and cellulase) were enhanced by fertilization at 195 or 244 kg N ha−1 yr−1, but was equivalent to or even lower than those in the unfertilized control when fertilization rate reached 305 kg N ha−1 yr−1. Results indicated that the activity of soil enzymes could be used as an important metric to diagnose the impacts of fertilization rates on soil. Fertilization rate at approximately 200 kg N ha−1 yr−1 appeared to be appropriate for managing putting greens.}, number={1-2}, journal={GEODERMA}, author={Liu, Yueyan and Dell, Emily and Yao, Huaiying and Rufty, Thomas and Shi, Wei}, year={2011}, month={Apr}, pages={215–221} }
 @article{carley_goodman_sermons_shi_bowman_miller_rufty_2011, title={Soil Organic Matter Accumulation in Creeping Bentgrass Greens: A Chronosequence with Implications for Management and Carbon Sequestration}, volume={103}, ISSN={1435-0645}, url={http://dx.doi.org/10.2134/agronj2010.0335}, DOI={10.2134/agronj2010.0335}, abstractNote={Excessive organic matter (OM) accumulation in creeping bentgrass (Agrostis palustris Huds.) putting greens, and its restriction of permeability, is one of the most difficult problems in turfgrass management. In this transition zone study, we characterized temporal and spatial aspects of OM accumulation, in an attempt to assess the effectiveness of management and to begin to uncover the processes controlling C sequestration. Root zone samples were collected from sand‐based putting greens at 49 golf courses of various ages, generating 212 individual observations. Organic matter accumulated hyperbolically over time in the top 2.5 cm; apparent critical levels of 40 g kg−1 were exceeded within 5 yr. At a depth of 2.5 to 7.6 cm, accumulation was much slower and linear over time, and critical levels were not reached even after 20 yr. Oxygen levels were never depressed more than 15%, indicating that intensive management of the upper soil profile was successfully allowing gas exchange into the root zone. Carbon accumulated in the soil profile hyperbolically, reflecting changes in the large OM pool near the soil surface. The sequestration rate of 59 g m−2 yr−1 over 25 yr was less than that observed by others examining soil under bentgrass greens in different environments. The evidence indicates that OM and C accumulation are strongly influenced by increasing microbial degradation rates as turfgrass systems age.}, number={3}, journal={Agronomy Journal}, publisher={American Society of Agronomy}, author={Carley, Danesha Seth and Goodman, David and Sermons, Shannon and Shi, Wei and Bowman, Dan and Miller, Grady and Rufty, Thomas}, year={2011}, pages={604} }
 @article{matthieu_bowman_thapa_cassel_rufty_2011, title={Turfgrass Root Response to Subsurface Soil Compaction}, volume={42}, ISSN={["1532-2416"]}, DOI={10.1080/00103624.2011.622826}, abstractNote={Soil compaction prevents turfgrass roots from growing deep into the soil and may limit access to water and nutrients. The objective of this study was to characterize the ability of turfgrass roots to penetrate a compacted subsurface layer. Seven turfgrasses were grown in soil columns. Each column was divided into three sections with the top and bottom packed to a bulk density of 1.6 g cm−3, and the middle (treatment) layer packed to 1.6, 1.7, 1.8, 1.9, or 2.0 g cm−3. Subsurface compaction reduced root mass for two of the species, and inhibited deep root growth in all seven species, with the greatest reduction occurring between 1.7 and 1.8 g cm−3. There appears to be little difference between species in ability to penetrate compacted soils, suggesting that soil preparation and routine management practices, rather than grass selection, is the more viable way to handle soil compaction problems in turf.}, number={22}, journal={COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS}, author={Matthieu, Donald E. and Bowman, Daniel C. and Thapa, Bir B. and Cassel, D. Keith and Rufty, Thomas W.}, year={2011}, pages={2813–2823} }
 @article{taylor_nelson_frantz_rufty_2010, title={PHOSPHORUS DEFICIENCY IN PELARGONIUM: EFFECTS ON NITRATE AND AMMONIUM UPTAKE AND ACIDITY GENERATION}, volume={33}, ISSN={["1532-4087"]}, DOI={10.1080/01904160903575923}, abstractNote={A sudden pH decline (SPD) of the substrate is an increasing problem in geranium growth systems, and the cause is unknown. In this study, we investigate whether a phosphorus (P) deficiency can cause SPD, and whether the effect is related to inhibition of ammonium (NH4 +) and nitrate (NO3 −) uptake and a corresponding shift in the cation to anion uptake balance. Geraniums (Pelargonium x hortorum Bailey ‘Designer Dark Red’) were grown in hydroponic solutions with or without P, and the hydroponics systems were located in a growth chamber programmed for light/dark temperatures of 22/18 or 26/22°C. Acidification potential was measured by the amount of base required to maintain pH at 5.8. The results indicated that much greater amounts of base were required to maintain a stable pH with P-limited plants. Using periodic exposures to 15NH4 + or 15NO3 −, it was found that NO3 − uptake was strongly inhibited as plants became P stressed. Tissue nutrient profiles showed that the NO3 − uptake inhibition was accompanied by an increase in the cation to anion uptake ratio. Rhizosphere acidification was greater at higher temperature even though the cation and anion responses were unchanged in control plants, suggesting the involvement of carbon dioxide (CO2) generated by root respiration. The results indicate that changes in cation and anion uptake and the associated increase in net H+ extrusion that occur under P-stress conditions can contribute to SPD in geranium culture systems.}, number={5}, journal={JOURNAL OF PLANT NUTRITION}, author={Taylor, Matthew D. and Nelson, Paul V. and Frantz, Jonathan M. and Rufty, Thomas W.}, year={2010}, pages={701–712} }
 @article{dell_bowman_rufty_shi_2010, title={The community composition of soil-denitrifying bacteria from a turfgrass environment}, volume={161}, ISSN={["1769-7123"]}, DOI={10.1016/j.resmic.2010.03.010}, abstractNote={Soil-denitrifying bacteria in highly-managed turfgrass systems were examined to assess their response to land-use change and time under management. Denitrifier community composition and diversity in a turfgrass chronosequence of 1 to 95-years-old were compared with those in an adjacent pine-dominant forest via molecular investigations of nirK and nosZ gene fragments. Both denaturing gradient gel electrophoresis and sequenced clone libraries revealed that the denitrifier community became more diverse after turf establishment, and the diversity was then preserved. Furthermore, the composition of the turfgrass denitrifier community was slightly affected by time under management. Meta-analysis of sequenced nirK and nosZ gene fragments from a variety of ecosystems showed that denitrifier communities in pine and turf were more similar to those in other environments than to each other, suggesting that land-use change substantially modified the composition and increased the diversity of denitrifiers. This study provides a useful baseline of nirK- and nosZ-type soil denitrifier communities to aid in the evaluation of ecological and environmental impacts of turfgrass systems.}, number={5}, journal={RESEARCH IN MICROBIOLOGY}, author={Dell, Emily A. and Bowman, Daniel and Rufty, Thomas and Shi, Wei}, year={2010}, month={Jun}, pages={315–325} }
 @article{wherley_shi_bowman_rufty_2009, title={Fate of N-15-Nitrate Applied to a Bermudagrass System: Assimilation Profiles in Different Seasons}, volume={49}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2008.08.0468}, abstractNote={ABSTRACT}, number={6}, journal={CROP SCIENCE}, author={Wherley, Benjamin G. and Shi, Wei and Bowman, Daniel C. and Rufty, Thomas W.}, year={2009}, pages={2291–2301} }
 @article{yao_bowman_rufty_shi_2009, title={Interactions between N fertilization, grass clipping addition and pH in turf ecosystems: Implications for soil enzyme activities and organic matter decomposition}, volume={41}, ISSN={0038-0717}, url={http://dx.doi.org/10.1016/j.soilbio.2009.03.020}, DOI={10.1016/j.soilbio.2009.03.020}, abstractNote={Turf has been acknowledged as an important ecosystem with potential for soil C sequestration. As a major process dictating soil C storage, organic matter decomposition has received little attention in turf systems. Given that soil enzyme-catalyzed biochemical reactions are the rate limiting steps of organic matter decomposition, we examined the activities of oxidative and hydrolytic soil enzymes and their relations with soluble organic compounds and soil C and N mineralization in two turf chronosequences with contrasting soil pH and in response to N fertilization and grass clipping addition. In comparison with turf ecosystems under acidic soil, phenol oxidase activity was about two-fold greater in turf ecosystems under alkaline soil and positively correlated to about two-fold differences in soluble phenolics and dissolved organic C between alkaline and acidic soils. However, the activities of hydrolytic enzymes including cellulase, chitinase, and glucosidase were lower in alkaline soil. It appears that the high concentration of soluble phenolics inhibited the activities of hydrolytic enzymes that in turn limited the decomposition of dissolved organic C and resulted in its accumulation in alkaline soil. Nitrogen mineralization was comparable between alkaline and acidic soils, but CO2 evolution was about two-fold greater in alkaline soil, possibly due to considerable abiotic carbonate dissolution. We observed that mineral N input at 60 mg N kg−1 soil had very minor negative effects on the activities of both phenol oxidase and hydrolytic enzymes. Grass clipping addition did not affect the activity of phenol oxidase, but increased the activities of soil chitinase, cellulase, glucosidase, and glucosaminidase by up to 20% and also soluble phenolics in soil by about 10%. Our results suggest that soil phenol oxidase might regulate the activities of hydrolytic soil enzymes via its control on soluble phenolics and function as an ‘enzymatic latch’ to hold soil organic C in highly managed turf ecosystems. While soil pH is important to affect phenol oxidase activity and therefore decomposition, management practices, i.e., N fertilization and grass clipping addition may indirectly affect the decomposition through enhancing turfgrass productivity and thus soil C input.}, number={7}, journal={Soil Biology and Biochemistry}, publisher={Elsevier BV}, author={Yao, Huaiying and Bowman, Daniel and Rufty, Thomas and Shi, Wei}, year={2009}, month={Jul}, pages={1425–1432} }
 @article{hixson_shi_weber_yelverton_rufty_2009, title={Soil Organic Matter Changes in Turfgrass Systems Affect Binding and Biodegradation of Simazine}, volume={49}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci2008.09.0541}, abstractNote={Concern about pesticide losses from maintained turfgrass areas led us to examine the fate of the triazine herbicide simazine in turfgrass systems and, specifically, interactions between simazine binding to soil organic matter and biodegradation. Soil samples were removed from turfgrass systems of different ages, placed in microcosms, conditioned as sterile or nonsterile, and exposed to 14C‐simazine. At seven sampling intervals, the soil was extracted and 14C was separated into three pools; bound, extractable, and CO2 With sterilized surface soil (0–5 cm), 52, 70, and 71% of applied 14C‐simazine was bound to soil from the 4‐, 21‐, and 99‐yr‐old turfgrass systems, respectively, after 16 wk. With nonsterile conditions, biodegradation became dominant, as 60 to 80% of the 14C was recovered in the CO2 fraction and binding was held at ∼20%. Among all soils evaluated, bound 14C and 14CO2 production was lower in subsurface soil (5–15 cm) from the 4‐ and 21‐yr‐old turfgrass systems. 14C‐simazine disappearance time (DT50) values under nonsterile conditions ranged from 0.9 to 5.8 wk. Results indicate that turfgrass systems have a relatively low amount of simazine available for leaching as the systems age due to a large capacity for biodegradation and binding to organic matter.}, number={4}, journal={CROP SCIENCE}, author={Hixson, Adam C. and Shi, Wei and Weber, Jerome B. and Yelverton, Fred H. and Rufty, Thomas W.}, year={2009}, pages={1481–1488} }
 @article{silva_cortes correa_novais_smyth_rufty_silva_gebrim_nunes_2009, title={TIMING, LOCATION AND CROP SPECIES INFLUENCE THE MAGNITUDE OF AMELIORATION OF ALUMINUM TOXICITY BY MAGNESIUM}, volume={33}, ISSN={["0100-0683"]}, DOI={10.1590/s0100-06832009000100007}, abstractNote={The protective effect of cations, especially Ca and Mg, against aluminum (Al) rhizotoxicity has been extensively investigated in the last decades. The mechanisms by which the process occurs are however only beginning to be elucidated. Six experiments were carried out here to characterize the protective effect of Mg application in relation to timing, location and crop specificity: Experiment 1 - Protective effect of Mg compared to Ca; Experiment 2 - Protective effect of Mg on distinct root classes of 15 soybean genotypes; Experiment 3 - Effect of timing of Mg supply on the response of soybean cvs. to Al; Experiment 4 - Investigating whether the Mg protective effect is apoplastic or simplastic using a split-root system; Experiment 5 - Protective effect of Mg supplied in solution or foliar spraying, and Experiment 6 - Protective effect of Mg on Al rhizotoxicity in other crops. It was found that the addition of 50 mmol L-1 Mg to solutions containing toxic Al increased Al tolerance in 15 soybean cultivars. This caused soybean cultivars known as Al-sensitive to behave as if they were tolerant. The protective action of Mg seems to require constant Mg supply in the external medium. Supplying Mg up to 6 h after root exposition to Al was sufficient to maintain normal soybean root growth, but root growth was not recovered by Mg addition 12 h after Al treatments. Mg application to half of the root system not exposed to Al was not sufficient to prevent Al toxicity on the other half exposed to Al without Mg in rooting medium, indicating the existence of an external protection mechanism of Mg. Foliar spraying with Mg also failed to decrease Al toxicity, indicating a possible apoplastic role of Mg. The protective effect of Mg appeared to be soybean-specific since Mg supply did not substantially improve root elongation in sorghum, wheat, corn, cotton, rice, or snap bean when grown in the presence of toxic Al concentrations.}, number={1}, journal={REVISTA BRASILEIRA DE CIENCIA DO SOLO}, author={Silva, Ivo Ribeiro and Cortes Correa, Tarcisio Fernando and Novais, Roberto Ferreira and Smyth, T. Jot and Rufty, Thomas and Silva, Eulene Francisco and Gebrim, Fabricio Oliveira and Nunes, Flancer Novais}, year={2009}, pages={65–76} }
 @article{dell_bowman_rufty_shi_2008, title={Intensive management affects composition of betaproteobacterial ammonia oxidizers in turfgrass systems}, volume={56}, ISSN={["1432-184X"]}, DOI={10.1007/s00248-007-9335-x}, abstractNote={Turfgrass is a highly managed ecosystem subject to frequent fertilization, mowing, irrigation, and application of pesticides. Turf management practices may create a perturbed environment for ammonia oxidizers, a key microbial group responsible for nitrification. To elucidate the long-term effects of turf management on these bacteria, we assessed the composition of betaproteobacterial ammonia oxidizers in a chronosequence of turfgrass systems (i.e., 1, 6, 23, and 95 years old) and the adjacent native pines by using both 16S rRNA and amoA gene fragments specific to ammonia oxidizers. Based on the Shannon-Wiener diversity index of denaturing gradient gel electrophoresis patterns and the rarefaction curves of amoA clones, turf management did not change the relative diversity and richness of ammonia oxidizers in turf soils as compared to native pine soils. Ammonia oxidizers in turfgrass systems comprised a suite of phylogenetic clusters common to other terrestrial ecosystems. Nitrosospira clusters 0, 2, 3, and 4; Nitrosospira sp. Nsp65-like sequences; and Nitrosomonas clusters 6 and 7 were detected in the turfgrass chronosequence with Nitrosospira clusters 3 and 4 being dominant. However, both turf age and land change (pine to turf) effected minor changes in ammonia oxidizer composition. Nitrosospira cluster 0 was observed only in older turfgrass systems (i.e., 23 and 95 years old); fine-scale differences within Nitrosospira cluster 3 were seen between native pines and turf. Further investigations are needed to elucidate the ecological implications of the compositional differences.}, number={1}, journal={MICROBIAL ECOLOGY}, author={Dell, Emily A. and Bowman, Daniel and Rufty, Thomas and Shi, Wei}, year={2008}, month={Jul}, pages={178–190} }
 @article{place_bowman_burton_rutty_2008, title={Root penetration through a high bulk density soil layer: differential response of a crop and weed species}, volume={307}, ISSN={["1573-5036"]}, DOI={10.1007/s11104-008-9594-4}, number={1-2}, journal={PLANT AND SOIL}, author={Place, George and Bowman, Daniel and Burton, Michael and Rutty, Thomas}, year={2008}, month={Jun}, pages={179–190} }
 @article{naegle_kwanyuen_burton_carter_rufty_2008, title={Seed nitrogen mobilization in soybean: Effects of seed nitrogen content and external nitrogen fertility}, volume={31}, ISSN={["1532-4087"]}, DOI={10.1080/01904160801894921}, abstractNote={ABSTRACT Soybean breeding programs have developed genetic lines with relatively low seed protein, which could negatively impact early seedling growth in low fertility conditions commonly encountered in the field. In these experiments, seed protein mobilization and its regulation in situ in soybean lines with different seed protein levels was investigated. The results showed that rates of nitrogen (N) release from cotyledons were much lower with decreasing levels of N in seed. Patterns of proteolysis of the storage proteins glycinin and β -conglycinin and their subunits were not different, but breakdown rates were slower. Seed N release rates increased somewhat when external N was supplied to roots of the developing seedlings, suggesting the involvement of source/sink controls. The effect appeared to be down-stream from proteolysis, as rates of protein breakdown were not altered. The results indicate that low seed protein levels will lead to reduced seedling fitness in low fertility soil conditions unless fertilizer N is applied.}, number={2}, journal={JOURNAL OF PLANT NUTRITION}, author={Naegle, Erin and Kwanyuen, Prachuab and Burton, Joseph and Carter, Thomas and Rufty, Thomas}, year={2008}, pages={367–379} }
 @article{sermons_burton_rufty_2008, title={Temperature response of Benghal dayflower (Commelina benghalensis): Implications for geographic range}, volume={56}, ISSN={["1550-2759"]}, DOI={10.1614/WS-08-029.1}, abstractNote={The noxious weed Benghal dayflower has become a severely troublesome agricultural weed in Georgia in the southeastern Unite States, and there are indications that it is moving northward. Benghal dayflower is glyphosate tolerant and possesses a high degree of reproductive elasticity, making it a formidable threat in many crop systems. The purpose of these experiments was to develop the first temperature response profiles for Benghal dayflower, and use them to evaluate whether temperature might limit its northward invasion into North Carolina and adjacent states on the U.S. east coast. Experiments focused on vegetative and early reproductive growth, stages considered crucial for establishment and competitiveness. Exposure to a range of aerial temperatures revealed that Benghal dayflower growth and production of aerial and subterranean reproductive structures were maximized at 30 C, with sharp declines occurring at cooler temperatures. When exposed to differing root temperatures in hydroponics, with a constant aerial temperature, Benghal dayflower growth did not show the same cool temperature sensitivity, but reproductive performance declined when temperatures decreased below about 29 C. The root temperature responses of several other weed species known to thrive in the climate of this geographic area also were determined. Growth of sicklepod, hemp sesbania, and jimsonweed was more sensitive than Benghal dayflower to cool temperatures, whereas the growth response of velvetleaf was similar. Based on the comparison of the Benghal dayflower temperature responses in controlled environments to (1) seasonal air and soil temperatures in the field, and (2) the temperature responses of agronomic weeds known to thrive in the region, it is concluded that cool temperatures will not restrain the northward spread of Benghal dayflower into North Carolina.}, number={5}, journal={WEED SCIENCE}, author={Sermons, Shannon M. and Burton, Michael G. and Rufty, Thomas W.}, year={2008}, pages={707–713} }
 @article{sinclair_fiscus_wherley_durham_rufty_2007, title={Atmospheric vapor pressure deficit is critical in predicting growth response of “cool-season” grass Festuca arundinacea to temperature change}, volume={227}, ISSN={0032-0935 1432-2048}, url={http://dx.doi.org/10.1007/s00425-007-0645-5}, DOI={10.1007/s00425-007-0645-5}, abstractNote={There is a lack of information on plant response to multifactor environmental variability including the interactive response to temperature and atmospheric humidity. These two factors are almost always confounded because saturated vapor pressure increases exponentially with temperature, and vapor pressure deficit (VPD) could have a large impact on plant growth. In this study using climate controlled mini-greenhouses, we examined the interacting influence of temperature and VPD on long-term growth of tall fescue (Festuca arundinacea Schreb), a cool season grass. From past studies it was expected that growth of tall fescue would decline with warmer temperatures over the range of 18.5-27 degrees C, but growth actually increased markedly with increasing temperature when VPD was held constant. In contrast, growth declined in experiments where tall fescue was exposed to increasing VPD and temperature was held constant at 21 degrees C. The inhibited growth appears to be in response to a maximum transpiration rate that can be supported by the tall fescue plants. The sensitivity to VPD indicates that if VPD remains stable in future climates as it has in the past, growth of tall fescue could well be stimulated rather than decreased by global warming in temperate climate zones.}, number={1}, journal={Planta}, publisher={Springer Science and Business Media LLC}, author={Sinclair, Thomas and Fiscus, Edwin and Wherley, Ben and Durham, Michael and Rufty, Thomas}, year={2007}, month={Oct}, pages={273–276} }
 @article{fiscus_booker_dubois_rufty_burton_pursley_2007, title={Carbon dioxide enhancement effects in container- versus ground-grown soybean at equal planting densities}, volume={47}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2006.12.0755}, abstractNote={Prior work showed that CO2 enhancement ratios (ER) were similar for plants grown in open‐top chambers (OTCs) whether grown in the ground or in insulated containers aboveground. Per plant comparisons were suspect since the ground‐grown plants were cultivated in rows at normal densities making it difficult to separate the effects of plant competition from the variables of interest. Soybean [Glycine max (L.) Merr. cv. Essex] was grown in the ground and in aboveground containers in OTCs in ambient and elevated CO2 at equal planting densities. The hypothesis was that at equal densities, container‐ and ground‐grown plants would exhibit both equivalent ERs and equivalent per plant yields. Although the only differences in net photosynthetic rate (An:μmol m−2 s−1) and conductance to water vapor (gs:mol m−2 s−1) were due to CO2 and container‐ and ground‐grown plants had similar ERs (mean = 20%), per plant yields were still less in the container‐grown plants at both levels of CO2 (mean = −17%). Reproductive measures, except mass per seed, as well as total stem biomass were significantly reduced in the containers. High CO2 increased seed oil concentration and the level of fatty acid saturation. The only observed environmental difference was higher daytime root zone temperatures in containers (2–6°C). The robust ERs suggest that neither above‐ nor below‐ground resource limitations was the cause of the yield discrepancies.}, number={6}, journal={CROP SCIENCE}, author={Fiscus, Edwin L. and Booker, Fitzgerald L. and Dubois, Jean-Jacques B. and Rufty, Thomas W. and Burton, Joseph W. and Pursley, Walter A.}, year={2007}, pages={2486–2494} }
 @article{tungate_israel_watson_rufty_2007, title={Potential changes in weed competitiveness in an agroecological system with elevated temperatures}, volume={60}, ISSN={["0098-8472"]}, DOI={10.1016/j.envexpbot.2006.06.001}, abstractNote={Increases in temperature due to global climate changes could significantly impact weed competitiveness and crop–weed interactions. Factors contributing to the responsiveness of a plant species to increasing temperature include the inherent genetic limitations of the species and the ability to acquire water and nutritional resources. The purpose of this study was to examine the temperature responses of selected species from a model agronomic system in the Southeastern U.S.: soybean (Glycine max), sicklepod (Senna obtusifolia) and prickly sida (Sida spinosa). We also determined temperature effects on mycorrhizal colonization and development of the soybean N2-fixation system, two below-ground associations critical for resource acquisition. The species were grown at 42/37 (day/night), 36/31, 32/27, 28/23, or 23/18 °C for 30 days in a field soil with naturally low fertility. Growth of the weed species was maximized at a higher temperature than that for soybean, 36/31 °C versus 32/27 °C, probably reflecting different geographical origins. At the optimal temperature, weeds had higher root:shoot mass ratios (1.3–1.5 versus 0.9) than soybean, and greater mycorrhizal colonization. In soybean, nodule weights, numbers, and total nitrogenase activity were highest at the growth temperature optimum but decreased considerably at higher temperatures. The results collectively indicate that increases in aerial temperatures above ∼32 °C would enhance weed competitiveness. Increased interference with soybean growth and yields should be expected.}, number={1}, journal={ENVIRONMENTAL AND EXPERIMENTAL BOTANY}, author={Tungate, Kimberly D. and Israel, Daniel W. and Watson, Dorothy M. and Rufty, Thomas W.}, year={2007}, month={May}, pages={42–49} }
 @article{tungate_burton_susko_sermons_rufty_2006, title={Altered weed reproduction and maternal effects under low-nitrogen fertility}, volume={54}, ISSN={["0043-1745"]}, DOI={10.1614/WS-05-145R.1}, abstractNote={The low-nitrogen status of highly weathered soils may offer a potential alternative for weed suppression in agricultural systems with N2-fixing crops. In this study, we used sicklepod as a model to evaluate weed response that might occur with managed reductions in nitrogen-soil fertility. A field study was conducted with the parental generation supplied 0, 112, 224, or 448 kg N ha−1. Decreased nitrogen fertility led to reduced shoot biomass, seed number, and total seed mass. Individual seed mass was lower, but seed % nitrogen was not affected. Analysis of seed-mass distribution confirmed that low parental fertility was associated with more small seeds as a proportion of total seeds produced. Additional experiments in hydroponics culture revealed slower growth rates of seedlings produced from small seeds when grown under low-nitrogen conditions. Competitiveness of plants from small (low nitrogen) and large (high nitrogen) seed classes was determined in a replacement-series experiment conducted in sand culture in a controlled environment at two densities and two levels of nitrogen nutrition. Plants produced from smaller seeds were less competitive in low-nitrogen fertility conditions, but plants from small and large seeds competed similarly when grown under high-nitrogen fertility. The results support the hypothesis that comprehensive management strategies to reduce nitrogen availability for weed growth in low-fertility conditions could decrease weed interference by decreasing growth and seed production of parental plants and through maternal effects that lower competitiveness of offspring.}, number={5}, journal={WEED SCIENCE}, author={Tungate, Kimberly D. and Burton, Michael G. and Susko, David J. and Sermons, Shannon M. and Rufty, Thomas W.}, year={2006}, pages={847–853} }
 @article{tu_booker_watson_chen_rufty_shi_hu_2006, title={Mycorrhizal mediation of plant N acquisition and residue decomposition: Impact of mineral N inputs}, volume={12}, ISSN={["1365-2486"]}, DOI={10.1111/j.1365-2486.2006.01149.x}, abstractNote={Abstract}, number={5}, journal={GLOBAL CHANGE BIOLOGY}, author={Tu, C and Booker, FL and Watson, DM and Chen, X and Rufty, TW and Shi, W and Hu, SJ}, year={2006}, month={May}, pages={793–803} }
 @article{moyer-henry_burton_israel_rufty_2006, title={Nitrogen transfer between plants: A N-15 natural abundance study with crop and weed species}, volume={282}, ISSN={["1573-5036"]}, DOI={10.1007/s11104-005-3081-y}, number={1-2}, journal={PLANT AND SOIL}, author={Moyer-Henry, K. A. and Burton, J. W. and Israel, D. W. and Rufty, T. W.}, year={2006}, month={Apr}, pages={7–20} }
 @article{moyer-henry_silva_macfall_johannes_allen_goldfarb_rufty_2005, title={Accumulation and localization of aluminium in root tips of loblolly pine seedlings and the associated ectomycorrhiza Pisolithus tinctorius}, volume={28}, ISSN={["1365-3040"]}, DOI={10.1111/j.1365-3040.2004.01240.x}, abstractNote={ABSTRACT}, number={2}, journal={PLANT CELL AND ENVIRONMENT}, author={Moyer-Henry, K and Silva, I and Macfall, J and Johannes, E and Allen, N and Goldfarb, B and Rufty, T}, year={2005}, month={Feb}, pages={111–120} }
 @article{chiera_thomas_rufty_2005, title={Growth and Localized Energy Status in Phosphorus-Stressed Soybean}, volume={27}, ISSN={0190-4167 1532-4087}, url={http://dx.doi.org/10.1081/PLN-200030007}, DOI={10.1081/PLN-200030007}, abstractNote={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.}, number={11}, journal={Journal of Plant Nutrition}, publisher={Informa UK Limited}, author={Chiera, Joseph M. and Thomas, Judith F. and Rufty, Thomas W.}, year={2005}, month={Jan}, pages={1875–1890} }
 @article{halfhill_sutherland_moon_poppy_warwick_weissinger_rufty_raymer_stewart_2005, title={Growth, productivity, and competitiveness of introgressed weedy Brassica rapa hybrids selected for the presence of Bt cry1Ac and gfp transgenes}, volume={14}, ISSN={["1365-294X"]}, DOI={10.1111/j.1365-294X.2005.02649.x}, abstractNote={Abstract}, number={10}, journal={MOLECULAR ECOLOGY}, author={Halfhill, MD and Sutherland, JP and Moon, HS and Poppy, GM and Warwick, SI and Weissinger, AK and Rufty, TW and Raymer, PL and Stewart, CN}, year={2005}, month={Sep}, pages={3177–3189} }
 @article{naegle_burton_carter_rufty_2005, title={Influence of seed nitrogen content on seedling growth and recovery from nitrogen stress}, volume={271}, ISSN={["1573-5036"]}, DOI={10.1007/s11104-004-3242-4}, number={1-2}, journal={PLANT AND SOIL}, author={Naegle, ER and Burton, JW and Carter, TE and Rufty, TW}, year={2005}, month={Apr}, pages={329–340} }
 @article{chiera_thomas_rufty_2004, title={Growth and localized energy status in phosphorus-stressed soybean}, volume={27}, ISSN={["1532-4087"]}, DOI={10.1081/LPLA-200030007}, abstractNote={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.}, number={11}, journal={JOURNAL OF PLANT NUTRITION}, author={Chiera, JM and Thomas, JF and Rufty, TW}, year={2004}, pages={1875–1890} }
 @article{causin_tremmel_rufty_reynolds_2004, title={Growths nitrogen uptake, and metabolism in two semiarid shrubs grown at ambient and elevated atmospheric CO2 concentrations: Effects of nitrogen supply and source}, volume={91}, ISSN={["1537-2197"]}, DOI={10.3732/ajb.91.4.565}, abstractNote={The effect of differences in nitrogen (N) availability and source on growth and nitrogen metabolism at different atmospheric CO2 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 NO3−, soluble proteins, organic acids) were measured in seedlings grown in controlled environment chambers for 48 d at ambient (350 ppm) and elevated (650 ppm) CO2 and fertilized with high (8.0 mmol/L) or low (0.8 mmol/L) N (Nlevel), supplied at either 1 : 1 or 3 : 1 NO3− : NH4+ ratios (Nsource). Responses to elevated CO2 depended on both Nlevel and Nsource, with the largest effects evident at high Nlevel. A high NO3− : NH4+ ratio stimulated growth responses to elevated CO2 in both species when N was limiting and increased the responses of P. flexuosa at high Nlevel. 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 CO2, provided that a high proportion of NO3‐ to NH4‐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 CO2, may indicate that these semiarid species will be better able to cope with both nutrient and water deficits as CO2 levels rise.}, number={4}, journal={AMERICAN JOURNAL OF BOTANY}, author={Causin, HF and Tremmel, DC and Rufty, TW and Reynolds, JE}, year={2004}, month={Apr}, pages={565–572} }
 @article{mcelroy_yelverton_neal_rufty_2004, title={Influence of photoperiod and temperature on vegetative growth and development of Florida betony (Stachys floridana)}, volume={52}, ISSN={["1550-2759"]}, DOI={10.1614/WS-03-045R}, abstractNote={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.}, number={2}, journal={WEED SCIENCE}, author={McElroy, JS and Yelverton, FH and Neal, JC and Rufty, TW}, year={2004}, pages={267–270} }
 @article{fagerness_bowman_yelverton_rufty_2004, title={Nitrogen use in Tifway bermudagrass, as affected by trinexapac-ethyl}, volume={44}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2004.5950}, abstractNote={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 15N‐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 15N allocation to clippings by ≈25% and increased 15N allocation to roots and rhizomes; total recovery of applied 15N in tissues was ≈65%. Results demonstrate chemical growth suppression with TE does not reduce N uptake or increase nitrate leaching from bermudagrass.}, number={2}, journal={CROP SCIENCE}, author={Fagerness, MJ and Bowman, DC and Yelverton, FH and Rufty, TW}, year={2004}, pages={595–599} }
 @article{jennette_rufty_macfall_2003, title={Magnetic resonance image visualization of plant roots in situ: A tool for characterizing root morphology}, ISBN={0891181520}, DOI={10.2134/asaspecpub66.c6}, abstractNote={Magnetic resonance imaging (MRI) is a technique that holds promise for the noninvasive study of root systems. The purpose of this chapter is to provide a brief overview of the MRI technique and evaluate new applications for MRI visualization of a crop plant—soybean. Soybean seedlings were grown for 8 days in sand, at optimum fertility and pH. Root systems were imaged in situ, without removal from soil, in a General Electric Signa MRI unit customized for high-resolution research studies. Three-dimensional renderings were produced using the software program VOXELVIEW. The images allowed relatively clear allowed visualization of primary, basal, and lateral roots, and calculations of root system volume were similar to those obtained from water displacement and water content estimates.}, journal={Digital imaging and spectral techniques : applications to precision agriculture and crop physiology : proceedings of a Symposium sponsored by Division C-2 of the Crop Science Society of America, the USDA-ARS, and the Rockfeller Foundation in Minneapolis, MN, November 2001}, publisher={Madison, Wis. : American Society of Agronomy}, author={Jennette, M. W. and Rufty, T. W. and MacFall, J. S.}, year={2003} }
 @article{lee_bowman_cassel_peacock_rufty_2003, title={Soil inorganic nitrogen under fertilized bermudagrass turf}, volume={43}, DOI={10.2135/cropsci2003.2470}, abstractNote={Managed turfgrass acreage in the southeastern USA is steadily increasing. There is public concern that fertilization of turfgrass systems, particularly additions of N on golf courses, might be adversely affecting groundwater quality due to nitrate leaching. This study was conducted to measure soil nitrate levels in situ under continuously managed bermudagrass (Cynodon spp.) and to evaluate influences from fertilization and mineralization. Two experimental sites were established on 50‐ and 75‐yr‐old golf course fairways in the Neuse and Cape Fear River basins in eastern North Carolina. Soil sampling was done seasonally. Results indicate that nitrate‐N levels were consistently low (1 to 4 mg kg−1 soil) and similar to adjacent natural areas throughout the 120‐cm sampling depths during the 2‐yr experiment at both sites. Levels were relatively uniform with depth and across several landscape positions. The soil nitrate levels under fertilized fairways were similar to those in adjacent nonfertilized natural areas, indicating minimal influence from turf management practices. From laboratory mineralization studies and soil temperature data, it was estimated that 60 to 154 kg N ha−1 would be released from organic N pools during the bermudagrass growing season (May to October). Because of similar temperature responses, it appeared that N release from mineralization would be synchronized with bermudagrass growth. Substantial bermudagrass growth in nonfertilized plots provided direct evidence that mineralization was a significant contributor to turf nutrition. There was no evidence that N fertilization or the ecology of the bermudagrass system posed inherent risks to water quality and the environment.}, number={1}, journal={Crop Science}, author={Lee, D. J. and Bowman, D. C. and Cassel, D. K. and Peacock, C. H. and Rufty, T. W.}, year={2003}, pages={247–257} }
 @article{halfhill_millwood_rufty_weissinger_stewart_2003, title={Spatial and temporal patterns of green fluorescent protein (GFP) fluorescence during leaf canopy development in transgenic oilseed rape, Brassica napus L.}, volume={22}, ISSN={["1432-203X"]}, DOI={10.1007/s00299-003-0696-4}, abstractNote={The green fluorescent protein (GFP) holds promise as a field-level transgene marker. One obstacle to the use of GFP is fluorescence variability observed within leaf canopies. In growth chamber and field experiments, GFP fluorescence in transgenic oilseed rape ( Brassica napus) was shown to be variable at each leaf position over time and among different leaves on the same plant. A leaf had its highest GFP fluorescence after emergence and, subsequently, its fluorescence intensity decreased. GFP fluorescence intensity was directly correlated with the concentration of soluble protein. The concentration of the genetically linked recombinant Bacillus thuringiensis (Bt) cry1Ac endotoxin protein also was examined, and GFP fluorescence was positively correlated with Bt throughout development. The results show that GFP can be used as an accurate transgene marker but that aspects of plant developmental should be taken into account when interpreting fluorescence measurements.}, number={5}, journal={PLANT CELL REPORTS}, author={Halfhill, MD and Millwood, RJ and Rufty, TW and Weissinger, AK and Stewart, CN}, year={2003}, month={Dec}, pages={338–343} }
 @article{bowman_cherney_rufty_2002, title={Fate and transport of nitrogen applied to six warm-season turfgrasses}, volume={42}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci2002.0833}, abstractNote={A greenhouse study compared six warm season turfgrasses {common bermudagrass [Cynodon dactylon (L.) Pers.], ‘Tifway’ hybrid bermudagrass (C. dactylon × transvaalensis), centipedegrass (Eremochloa ophiuroides (Munro) Hack.), ‘Raleigh’ St. Augustinegrass [Stenotaphrum secundatum (Walter) Kuntze], ‘Meyer’ zoysiagrass (Zoysia japonica Steud.), and ‘Emerald’ zoysiagrass (Z. japonica × tenuifolia)] for NO3-N leaching and N use efficiency. Sod was established in sand-filled columns and managed under worst-case conditions to promote nitrate leaching. Ammonium nitrate was applied at 50 kg N ha−1 on seven dates, with the final application labeled with 15N. Leachate samples were collected and analyzed for NO3-N and NH4-N and clippings were analyzed for total N. Leaching losses were high following the first N application, ranging from 48 to 100% of the NO3-N and 4 to 16% of the NH4-N applied. Nitrate loss from subsequent applications was reduced substantially, while NH4 leaching was essentially eliminated. There were significant differences among species for leachate NO3-N concentration and cumulative N leached, with St. Augustinegrass being the most effective and Meyer zoysiagrass the least effective at minimizing NO3 leaching. Nitrogen recovery by the turf ranged from 63% for Meyer zoysiagrass to 84% for hybrid bermudagrass. Root length density (RLD) varied significantly among species at depths >30 cm, and was negatively correlated with NO3 leaching loss. These results document differences between the warm season turfgrasses for NO3 leaching potential, possibly related to root distribution, and emphasize that species selection is an important factor in minimizing environmental impacts from turfgrass management.}, number={3}, journal={CROP SCIENCE}, author={Bowman, DC and Cherney, CT and Rufty, TW}, year={2002}, pages={833–841} }
 @article{chiera_thomas_rufty_2002, title={Leaf initiation and development in soybean under phosphorus stress}, volume={53}, ISSN={["0022-0957"]}, DOI={10.1093/jexbot/53.368.473}, abstractNote={Experiments investigated changes in leaf development in young soybean plants progressing into P stress. The apical meristem and leaf structure were examined anatomically to evaluate the involvement of cell division and cell expansion in the restriction of leaf number and individual leaf size. Seedlings were deprived of P for 32 d following germination. Leaf initiation rates declined noticeably after about 2 weeks, even though the apical dome was of similar size and had a similar number of cells as controls. Primordia appeared morphologically similar also. Expansion of primary and the first three trifoliolate leaves of -P plants was severely reduced, and expansion of each leaf ceased, uniformly, when an area of about 40 cm(2) was obtained. Leaf epidermal cell size in the lateral plane was unaffected. The results indicate that expansion of leaves under P stress was limited by the number of cell divisions, which would imply control of cell division by a common regulatory factor within the leaf canopy.}, number={368}, journal={JOURNAL OF EXPERIMENTAL BOTANY}, author={Chiera, J and Thomas, J and Rufty, T}, year={2002}, month={Mar}, pages={473–481} }
 @article{tungate_susko_rufty_2002, title={Reproduction and offspring competitiveness of Senna obtusifolia are influenced by nutrient availability}, volume={154}, ISSN={["0028-646X"]}, DOI={10.1046/j.1469-8137.2002.00407.x}, abstractNote={Summary}, number={3}, journal={NEW PHYTOLOGIST}, author={Tungate, KD and Susko, DJ and Rufty, TW}, year={2002}, month={Jun}, pages={661–669} }
 @article{fagerness_yelverton_livingston_rufty_2002, title={Temperature and trinexapac-ethyl effects on bermudagrass growth, dormancy, and freezing tolerance}, volume={42}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci2002.0853}, abstractNote={Applications of the plant growth regulator (PGR) trinexapac-ethyl [4-(cyclopropyl-α-hydroxymethylene)-3,5-dioxocyclohexane carboxylic acid ethylester] (TE) can delay winter dormancy in ‘Tifway’ bermudagrass (Cynodon dactylon var. dactylon), which suggests a response to TE when temperatures are suboptimum for bermudagrass growth. The purpose of this study was to investigate the interactive role of temperature and TE in bermudagrass growth responses, dormancy, and freezing tolerance. Trinexapac-ethyl (0.11 kg a.i. ha−1) was applied in two growth chamber experiments, and across a 2-yr period in the field. Results indicated that TE reduced vertical shoot growth and increased stolon production, turf density, and quality when applied at high temperatures (35–36°C). While TE effectively reduced vertical shoot growth at low (20–22°C) temperatures, little impact on stolon development was observed under these conditions. Autumn applications of TE when temperatures were cool (≈25°C) at the time of application led to decreased turfgrass density and quality. These responses may explain the effectiveness of using TE to aid in bermudagrass transition to overseeded cool-season grasses and were probably due to the limited ability of bermudagrass to recover from initial post-application growth reduction and observed leaf chlorosis. Observed delayed autumn dormancy due to summer applications of TE and accelerated dormancy due to late-season applications did not conclusively relate to the freezing tolerance of bermudagrass.}, number={3}, journal={CROP SCIENCE}, author={Fagerness, MJ and Yelverton, FH and Livingston, DP and Rufty, TW}, year={2002}, pages={853–858} }
 @article{silva_smyth_israel_rufty_2001, title={Altered aluminum inhibition of soybean root elongation in the presence of magnesium}, volume={230}, DOI={10.1023/A:1010384516517}, number={2}, journal={Plant and Soil}, author={Silva, I. R. and Smyth, T. J. and Israel, D. W. and Rufty, T. W.}, year={2001}, pages={223–230} }
 @article{bigelow_bowman_cassel_rufty_2001, title={Creeping bentgrass response to inorganic soil amendments and mechanically induced subsurface drainage and aeration}, volume={41}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci2001.413797x}, abstractNote={Creeping bentgrass (Agrostis stolonifera var. palustris Huds. Farw.) golf greens often decline under the hot, humid summer conditions of the southeastern USA. Factors associated with this decline may be poor soil aeration, excessive soil wetness, high temperatures, and turfgrass diseases. A field study evaluated a mechanical forced air system for its ability to modify the soil water content and oxygen (O2) status of newly constructed sand‐based rootzones, and its effects on turfgrass quality (TQ) and seasonal bentgrass rooting. Three drainage situations were studied: gravity drainage (control treatment) and gravity drainage supplemented by two mechanically induced drainage treatments, water evacuation (WE) or WE followed by air‐injection (AI). In addition, the effects of peat moss and several inorganic soil amendments on bentgrass establishment and growth were studied. Compared with gravity drainage, WE significantly decreased water contents (0.01–0.05 m3 m−3) averaged across the 0‐ to 27‐cm depth, with the greatest change occurring near the bottom of the rooting media. Seasonal fluctuations in soil O2 and CO2 concentrations were observed, but O2 remained high, 0.19 m3 m−3, and CO2 was low, <0.01 m3 m−3, regardless of drainage treatment. Drainage treatments had no effect on TQ or root mass density (RMD). However, both TQ and RMD increased from 1998 to 1999, possibly becaue of greater turfgrass density. Amendments had significant effects on establishment and TQ in the following order: peat moss > Ecolite = Profile > Greenschoice ≥ unamended sand. This response was probably due to improved water and nutrient retention of the amended rootzones. Although the forced air–vacuum technology provided little benefit in these newly constructed greens, it may be useful on mature putting greens that suffer from poor soil aeration or drainage.}, number={3}, journal={CROP SCIENCE}, author={Bigelow, CA and Bowman, DC and Cassel, DK and Rufty, TW}, year={2001}, pages={797–805} }
 @article{silva_smyth_raper_carter_rufty_2001, title={Differential aluminum tolerance in soybean: An evaluation of the role of organic acids}, volume={112}, ISSN={["1399-3054"]}, DOI={10.1034/j.1399-3054.2001.1120208.x}, abstractNote={The role of organic acids in aluminum (Al) tolerance has been the object of intensive research. In the present work, we evaluated the roles of organic acid exudation and concentrations at the root tip on Al tolerance of soybean. Exposing soybean seedlings to Al3+ activities up to 4.7 μM in solution led to different degrees of restriction of primary root elongation. Al tolerance among genotypes was associated with citrate accumulation and excretion into the external media. Citrate and malate efflux increased in all genotypes during the first 6 h of Al exposure, but only citrate efflux in Al‐tolerant genotypes was sustained for an extended period. Tolerance to Al was correlated with the concentration of citrate in root tips of 8 genotypes with a range of Al sensitivities (r2=0.75). The fluorescent stain lumogallion indicated that more Al accumulated in root tips of the Al‐sensitive genotype Young than the Al‐tolerant genotype PI 416937, suggesting that the sustained release of citrate from roots of the tolerant genotype was involved in Al exclusion. The initial stimulation of citrate and malate excretion and accumulation in the tip of all genotypes suggested the involvement of additional tolerance mechanisms. The experiments included an examination of Al effects on lateral root elongation. Extension of lateral roots was more sensitive to Al than that of tap roots, and lateral root tips accumulated more Al and had lower levels of citrate.}, number={2}, journal={PHYSIOLOGIA PLANTARUM}, author={Silva, IR and Smyth, TJ and Raper, CD and Carter, TE and Rufty, TW}, year={2001}, month={Jun}, pages={200–210} }
 @article{villagarcia_carter_rufty_niewoehner_jennette_arrellano_2001, title={Genotypic rankings for aluminum tolerance of soybean roots grown in hydroponics and sand culture}, volume={41}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2001.4151499x}, abstractNote={Screening methodology remains a practical barrier in the breeding of Al‐tolerant soybean [Glycine max (L.) Merr.]. Our objectives were to (i) develop a repeatable sand‐media culture method for Al tolerance screening of plants, (ii) compare Al response of genotypes in sand culture to a standard hydroponics‐based seedling culture, and (iii) establish a practical guide for the use of hydroponics and sand‐culture screening methods in the selection of Al‐tolerant soybean. We developed a sand‐media culture method and imposed 0 and 450 μM Al3+ activity treatments upon 10 diverse soybean genotypes. The experiment employed a randomized complete block design with nine replications. Root weight and relative root surface area (RRSA) were determined at 18 d after transplanting (DAT). In hydroponics, the genotypes were compared for taproot elongation after 3 d of exposure to 0, 2, and 5 μM Al3+ activity treatments in a split plot design with six replications. Aluminum stress was imposed successfully (approximately 57% of the growth in control) in hydroponics and sand culture, but discrepancies between methods were apparent. The hydroponics‐based seedling screen produced an inflated range of genotypic response and altered Al tolerance rankings in comparison with sand culture. ‘Perry’, which was tolerant to Al in sand culture, was remarkably sensitive to Al in hydroponics. Despite the discrepancies, seedling‐based screening successfully identified three (PI 417021, PI 416937, and Biloxi) of the four genotypes that were most tolerant to Al in sand culture. Results suggested that seedling screens can play a practical role in breeding. However, their application to a specific breeding population should be validated with older plants and solid media. The RRSA appeared to be a promising measure of A1 tolerance for soybean roots.}, number={5}, journal={CROP SCIENCE}, author={Villagarcia, MR and Carter, TE and Rufty, TW and Niewoehner, AS and Jennette, MW and Arrellano, C}, year={2001}, pages={1499–1507} }
 @article{silva_smyth_israel_raper_rufty_2001, title={Magnesium ameliorates aluminum rhizotoxicity in soybean by increasing citric acid production and exudation by roots}, volume={42}, ISSN={["1471-9053"]}, DOI={10.1093/pcp/pce067}, abstractNote={Superior effectiveness of Mg over Ca in alleviating Al rhizotoxicity cannot be accounted for by predicted changes in plasma membrane Al3+ activity. The influence of Ca and Mg on the production and secretion of citrate and malate, and on Al accumulation by roots was investigated with soybean genotypes Young and PI 416937 which differ in Al tolerance. In the presence of a solution Al3+ activity of 4.6 microM, citrate and malate concentrations of tap root tips of both genotypes increased with additions of either Ca up to 3 mM or Mg up to 50 microM. Citrate efflux rate from roots exposed to Al was only enhanced with Mg additions and exceeded malate efflux rates by as much as 50-fold. Maximum citrate release occurred within 12 h after adding Mg to solution treatments. Adding 50 microM Mg to 0.8 mM CaSO4 solutions containing Al3+ activities up to 4.6 microM increased citrate concentration of tap root tips by 3- to 5-fold and root exudation of citrate by 6- to 9-fold. Plants treated with either 50 microM Mg or 3 mM Ca had similar reductions in Al accumulation at tap root tips, which coincided with the respective ability of these ions to relieve Al rhizotoxicity. Amelioration of Al inhibition of soybean root elongation by low concentrations of Mg in solution involved Mg-stimulated production and efflux of citrate by roots.}, number={5}, journal={PLANT AND CELL PHYSIOLOGY}, author={Silva, IR and Smyth, TJ and Israel, DW and Raper, CD and Rufty, TW}, year={2001}, month={May}, pages={546–554} }
 @article{silva_smyth_israel_raper_rufty_2001, title={Magnesium is more efficient than calcium in alleviating aluminum rhizotoxicity in soybean and its ameliorative effect is not explained by the Gouy-Chapman-Stern model}, volume={42}, ISSN={["1471-9053"]}, DOI={10.1093/pcp/pce066}, abstractNote={The mechanistic basis for cation amelioration of Al rhizotoxicity in soybean was investigated through a series of studies comparing protective effects of Ca and Mg against Al inhibition of root elongation in a background 0.8 mM CaSO4 solution (pH 4.3). A modified Gouy-Chapman-Stern model was used to evaluate the effect of cations on electrical potential and Al3+ activity at root plasma membrane surfaces. Activities of Al3+ up to 4.6 microM in the background solution inhibited soybean tap root elongation by more than 80%. There was little or no response in root elongation when Ca and Mg were added to background solutions in the absence of AL: When added to Al-toxic solutions in the micromolar concentration range, Mg was 100-fold more effective than Ca in alleviating Al toxicity, whereas both cations were equally effective when added in the millimolar concentration range. The protective effect of micromolar additions of Mg on root elongation was specific for Al and it failed to alleviate La rhizotoxicity. In contrast to wheat, Mg amelioration of Al toxicity to soybean root elongation at low Mg concentration could not be explained by changes in potential and Al3+ activity at the root plasma membrane surfaces as predicted by a Gouy-Chapman-Stern model. These results suggest that Mg is not acting as an indifferent cation when present at low concentration and implies the involvement of a mechanism other than pure electrostatic effects at the root surface.}, number={5}, journal={PLANT AND CELL PHYSIOLOGY}, author={Silva, IR and Smyth, TJ and Israel, DW and Raper, CD and Rufty, TW}, year={2001}, month={May}, pages={538–545} }
 @article{lee_wollum_bowman_peacock_rufty_2001, title={Temperature effects on nitrogen mineralization in bermudagrass turf}, volume={9}, journal={International Turfgrass Society Research Journal}, author={Lee, D. J. and Wollum, A. G. and Bowman, D. C. and Peacock, C. H. and Rufty, T. W., Jr.}, year={2001}, pages={394} }
 @article{silva_smyth_moxley_carter_allen_rufty_2000, title={Aluminum accumulation at nuclei of cells in the root tip. Fluorescence detection using lumogallion and confocal laser scanning microscopy}, volume={123}, ISSN={["1532-2548"]}, DOI={10.1104/pp.123.2.543}, abstractNote={Abstract}, number={2}, journal={PLANT PHYSIOLOGY}, author={Silva, IR and Smyth, TJ and Moxley, DF and Carter, TE and Allen, NS and Rufty, TW}, year={2000}, month={Jun}, pages={543–552} }
 @article{bianchi-hall_carter_bailey_mian_rufty_ashley_boerma_arellano_hussey_parrott_2000, title={Aluminum tolerance associated with quantitative trait loci derived from soybean PI 416937 in hydroponics}, volume={40}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2000.402538x}, abstractNote={Acid soils with high levels of Al impede root growth, causing increased crop sensitivity to drought and decreased nutrient acquisition. Development of Al‐tolerant cultivars may be a cost effective response to the problem. In previous investigations, we identified an Al‐tolerant soybean [Glycine max (L.) Merr.] plant introduction from Japan (PI 416937), and subsequently determined the heritability of the trait in a cross with Young, a highly productive Al‐sensitive cultivar. The objective of the present study was to identify quantitative trait loci (QTL) which condition Al tolerance by a genetic linkage map of 155 restriction fragment length polymorphism (RFLP) marker loci and a hydroponics‐based Al response. The 120 F4‐derived progeny from Young × PI 416937 were divided into four sets and evaluated with the parents for tap root extension in 0 and 2 μM Al3+ activity solutions (NOAL and HIAL, respectively) employing Al levels as whole plots in a split‐plot experimental design. Aluminum tolerance was defined as (i) root extension under HIAL conditions, and (ii) root extension as a percentage of control [PC = (HIAL/NOAL) × 100]. Multiple regression analysis revealed five QTL from independent linkage groups which conditioned root extension under HIAL stress. Three of the five QTL were also detected by PC as the expression of Al tolerance. While most alleles for Al tolerance were derived from the Al‐tolerant parent, PI 416937, a RFLP allele from Young (for marker EV2‐1) improved Al tolerance expressed as PC and exhibited a similar trend under HIAL stress. At present, it is not known whether the Al tolerance gene from Young, in combination with those from PI 416937, will raise Al tolerance beyond that now observed in the PI. One allele for Al tolerance from PI 416937 (for marker B122‐1) may be difficult to capitalize upon, agronomically, because of its association with a detrimental pod dehiscence factor. Further experimentation is needed to distinguish between linkage and pleiotropic effects near this marker. A favorable epistatic effect for Al tolerance was detected between two alleles from the PI 416937. The relationships revealed by marker analysis indicated that marker‐facilitated selection may be a viable approach in the breeding of Al‐tolerant soybean.}, number={2}, journal={CROP SCIENCE}, author={Bianchi-Hall, CM and Carter, TE and Bailey, MA and Mian, MAR and Rufty, TW and Ashley, DA and Boerma, HR and Arellano, C and Hussey, RS and Parrott, WA}, year={2000}, pages={538–545} }
 @article{jackson_rufty_heagle_severson_eckel_2000, title={Survival and development of tobacco hornworm larvae on tobacco plants grown under elevated levels of ozone}, volume={26}, ISSN={["0098-0331"]}, DOI={10.1023/A:1005440025509}, number={1}, journal={JOURNAL OF CHEMICAL ECOLOGY}, author={Jackson, DM and Rufty, TW and Heagle, AS and Severson, RF and Eckel, RVW}, year={2000}, month={Jan}, pages={1–19} }
 @article{wright_coble_raper_rufty_1999, title={Comparative responses of soybean (Glycine max), sicklepod (Senna obtusifolia), and Palmer amaranth (Amaranthus palmeri) to root zone and aerial temperatures}, volume={47}, number={2}, journal={Weed Science}, author={Wright, S. R. and Coble, H. D. and Raper, C. D. and Rufty, T. W.}, year={1999}, pages={167–174} }
 @article{growth and nutrition of flu-cured tobacco exposured to aluminum in solution culture._1999, volume={43}, number={1}, journal={Tobacco Science}, year={1999}, pages={1–6} }
 @article{wright_jennette_coble_rufty_1999, title={Root morphology of young Glycine max, Senna obtusifolia, and Amaranthus palmeri}, volume={47}, number={6}, journal={Weed Science}, author={Wright, S. R. and Jennette, M. W. and Coble, H. D. and Rufty, T. W.}, year={1999}, pages={706–711} }
 @article{gojon_dapoigny_lejay_tillard_rufty_1998, title={Effects of genetic modification of nitrate reductase expression on (NO3-)-N-15 uptake and reduction in Nicotiana plants}, volume={21}, ISSN={["0140-7791"]}, DOI={10.1046/j.1365-3040.1998.00269.x}, abstractNote={The physiological consequences for NO3– utilization by the plant of underexpression and overexpression of nitrate reductase (NR) were investigated in nine transformants of Nicotiana tabacum and Nicotiana plumbaginifolia. The in vitro NR activities (NRAs) in both roots and leaves of low- and high-NR tobacco transformants ranged from 5–10% to 150–200%, respectively, of those measured in wild-type plants. The level of NR expression markedly affected the NO3– reduction efficiency in detached leaves and intact plants. In both species, 15NO3– reduction ranged from 15–45% of 15NO3– uptake in the low-NR plants, to 40–80% in the wild-type, and up to 95% in high-NR plants. In the high-NR genotypes, however, total 15NO3– assimilation was not significantly increased when compared with that in wild-type plants, because the higher 15NO3– reduction efficiency was offset by lower 15NO3– uptake by the roots. The inhibition of NO3– uptake appeared to be the result of negative feedback regulation of NO3– influx, and is interpreted as an adjustment of NO3– uptake to prevent excessive amino acid synthesis. In genotypes underexpressing NR, the low 15NO3– reduction efficiency also was generally associated with a decrease in net 15NO3– uptake as compared with the wild type. Thus, underexpression of NR resulted in an inhibition of reduced 15N synthesis in the plant, although the effect was much less pronounced than that expected from the very low NRAs. The restricted NO3– uptake in low-NR plants emphasizes the point that the products of NO3– assimilation are not the only factors responsible for down-regulation of the NO3– uptake system.}, number={1}, journal={PLANT CELL AND ENVIRONMENT}, author={Gojon, A and Dapoigny, L and Lejay, L and Tillard, P and Rufty, TW}, year={1998}, month={Jan}, pages={43–53} }
 @article{bianchi-hall_carter_rufty_arellano_boerma_ashley_burton_1998, title={Heritability and resource allocation of aluminum tolerance derived from soybean PI 416937}, volume={38}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci1998.0011183X003800020040x}, abstractNote={Aluminum toxicity restricts soybean [Glycine max (L.) Merr.] yield in many growing areas. When correction of toxicity by management is impractical, an economically sound alternative is to develop Al tolerant cultivars. Heritability (h 2 ) estimates for Al tolerance in hydroponics would aid in the efficient design of selection programs for cultivar development. Our objectives were to determine the h 2 of Al tolerance in a F 4 -derived population using tap root extension in hydroponics culture as the indicator of tolerance. The 120 random F 4 -derived lines of sensitive 'Young' x tolerant PI 416937 were evaluated in the absence (NOAL) and presence (HIAL) of Al (2 μM Al 3+ activity) by means of a split-plot design. Aluminum stress increased seedling tap root extension 3% in PI 416937 and decreased extension in Young 53%. Mean progeny performance decreased 31%. Analysis of variance revealed significant (P < 0.05) progeny and progeny x Al interaction effects, indicating heritable genetic variation for Al tolerance. The h 2 under HIAL was moderate (0.57) on a single-replication basis and high (0.87) based upon five replicates, indicating the relative ease by which Al tolerance may be improved. Tolerance expressed as percent of control (PC) had a similar h 2 . Approximately 6% of the F 4 -derived progeny in this study were numerically similar to the parents for Al response under HIAL, suggesting that three to five genes may control Al tolerance and that a population size of 150 random inbred lines may be needed to assure full recovery of Al tolerance in the progeny of future breeding populations. Expected gain and risk avoidance analysis suggested that two or three replications are sufficient for initial screening of single seed descent (SSD) populations derived from the PI 416937 and that employment of this PI as a control enhances the ability of the breeder to discard inferior types during screening. Practical advice is presented to assist plant breeders in the efficient improvement of Al tolerance in soybean.}, number={2}, journal={CROP SCIENCE}, author={Bianchi-Hall, CM and Carter, TE and Rufty, TW and Arellano, C and Boerma, HR and Ashley, DA and Burton, JW}, year={1998}, pages={513–522} }
 @article{bowman_devitt_engelke_rufty_1998, title={Root architecture affects nitrate leaching from bentgrass turf}, volume={38}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci1998.0011183X003800060036x}, abstractNote={Understanding the determinants of nitrate leaching should improve nitrogen uptake efficiency and reduce ground water contamination. This column lysimeter study examined the effect of root architecture on NO3 leaching from two genotypes of creeping bentgrass (Agrostis palustris Huds.) differing in rooting characteristics. Ammonium nitrate was applied (50 kg N ha−1) and the columns were irrigated with 1, 2 or 3 cm day−1 (Exp. 1) or irrigation was delayed 1, 3 or 5 d (Exp. 2). In Exp. 1, leachate NO3 concentrations and total N leached from the shallow‐rooted (SR) genotype were approximately twice those from the deep‐rooted (DR) genotype. An average of 38 and 18% of the applied N leached from the SR and DR genotypes, respectively. Cumulative leaching losses increased with irrigation depth. In Exp. 2, NO3 leaching was reduced 90% or more by increasing the time period for immobilization from 1 to 5 d. Recovery of applied 15N in the tissue averaged 87% after 2 mo. Absorption of NO3 and NH4 was measured in nutrient solution culture. The SR genotype had significantly higher uptake rates than DR for both forms of N, expressed on a root weight basis. Collectively these data indicate that a deep‐rooted turfgrass absorbs N more efficiently than a shallowrooted turf, reducing the concentration and total amount of NO3 leached. The effect is apparently not due to differences in N uptake, but rather to rooting patterns. Environmental conditions and management practices that affect rooting depth and density may thus affect N nutrition and NO3 leaching.}, number={6}, journal={CROP SCIENCE}, author={Bowman, DC and Devitt, DA and Engelke, MC and Rufty, TW}, year={1998}, pages={1633–1639} }
 @article{agrell_larsson_larsson_mackown_rufty_1997, title={Initial kinetics of N-15-nitrate labelling of root and shoot N fractions of barley cultured at different relative addition rates of nitrate-N}, volume={35}, number={12}, journal={Plant Physiology and Biochemistry}, author={Agrell, D. and Larsson, C. M. and Larsson, M. and MacKown, C. T. and Rufty, T. W.}, year={1997}, pages={923–931} }
 @article{ameziane_cassan_dufosse_rufty_limami_1997, title={Phosphate availability in combination with nitrate availability affects root yield and chicon yield and quality of Belgian endive (Cichorium intybus)}, volume={191}, ISSN={["1573-5036"]}, DOI={10.1023/A:1004230520073}, number={2}, journal={PLANT AND SOIL}, author={Ameziane, R and Cassan, L and Dufosse, C and Rufty, TW and Limami, AM}, year={1997}, month={Apr}, pages={269–277} }
 @article{rufty_mackown_lazof_carter_1995, title={EFFECTS OF ALUMINUM ON NITRATE UPTAKE AND ASSIMILATION}, volume={18}, ISSN={["0140-7791"]}, DOI={10.1111/j.1365-3040.1995.tb00192.x}, abstractNote={ABSTRACT}, number={11}, journal={PLANT CELL AND ENVIRONMENT}, author={RUFTY, TW and MACKOWN, CT and LAZOF, DB and CARTER, TE}, year={1995}, month={Nov}, pages={1325–1331} }
 @article{rufty_volk_glass_1992, title={Relationship between carbohydrate availability and assimilation of nitrate}, ISBN={0198577524}, journal={Nitrogen metabolism of plants}, publisher={Oxford : Clarendon Press}, author={Rufty, T. W., Jr. and Volk, R. J. and Glass, A. D. M.}, editor={K. Mengel and Pilbeam, D.J.Editors}, year={1992}, pages={103} }
 @article{rufty_mackown_volk_1990, title={ALTERATIONS IN NITROGEN ASSIMILATION AND PARTITIONING IN NITROGEN STRESSED PLANTS}, volume={79}, ISSN={["0031-9317"]}, DOI={10.1111/j.1399-3054.1990.tb05870.x}, abstractNote={Although nutrient stress is known to alter partitioning between shoots and roots, the physiological basis for the phenomenon is unresolved. Experiments were conducted to examine assimilation of 15NO3 by N‐stressed plants and to determine whether apparent changes in assimilation in the root contributed to alterations in whole‐plant partitioning of reduced‐N. Tobacco plants (Nicotiana tabacum L. cv. NC 2326) were exposed to a low concentration of NO3− in solution (80 μM) for 9 days to effect a N‐stress response. Exposure of plants to 1000 μM15NO3− for 12 h on selected days revealed that roots of N‐stressed plants developed an increased capacity to absorb NO3−, and accumulation of reduced‐15N in the root increased to an even greater extent. When plants were exposed to 80 or 1000 μM15NO3− in steady‐state, 15NO3− uptake over a 12 h period was noticeably restricted at the lower concentration, but a larger proportion of the absorbed 15N still accumulated as reduced‐15N in the root. The alteration in reduced‐15N partitioning was maintained in N‐stressed plants during the subsequent 3‐day “chase” period when formation of insoluble reduced‐15N in the root was quantitatively related to the disappearance of 15NO3− and soluble reduced‐15N. The results indicate that increased assimilation of absorbed NO3−, in the root may contribute significantly to the altered reduced‐N partitioning which occurs in N‐stressed plants.}, number={1}, journal={PHYSIOLOGIA PLANTARUM}, author={RUFTY, TW and MACKOWN, CT and VOLK, RJ}, year={1990}, month={May}, pages={85–95} }
 @article{rufty_mackown_israel_1990, title={PHOSPHORUS STRESS EFFECTS ON ASSIMILATION OF NITRATE}, volume={94}, ISSN={["0032-0889"]}, DOI={10.1104/pp.94.1.328}, abstractNote={An experiment was conducted to investigate alterations in uptake and assimilation of NO(3) (-) by phosphorus-stressed plants. Young tobacco plants (Nicotiana tabacum [L.], cv NC 2326) growing in solution culture were deprived of an external phosphorus (P) supply for 12 days. On selected days, plants were exposed to (15)NO(3) (-) during the 12 hour light period to determine changes in NO(3) (-) assimilation as the P deficiency progressed. Decreased whole-plant growth was evident after 3 days of P deprivation and became more pronounced with time, but root growth was unaffected until after day 6. Uptake of (15)NO(3) (-) per gram root dry weight and translocation of absorbed (15)NO(3) (-) out of the root were noticeably restricted in -P plants by day 3, and effects on both increased in severity with time. Whole-plant reduction of (15)NO(3) (-) and (15)N incorporation into insoluble reduced-N in the shoot decreased after day 3. Although the P limitation was associated with a substantial accumulation of amino acids in the shoot, there was no indication of excessive accumulation of soluble reduced-(15)N in the shoot during the 12 hour (15)NO(3) (-) exposure periods. The results indicate that alterations in NO(3) (-) transport processes in the root system are the primary initial responses limiting synthesis of shoot protein in P-stressed plants. Elevated amino acid levels evidently are associated with enhanced degradation of protein rather than inhibition of concurrent protein synthesis.}, number={1}, journal={PLANT PHYSIOLOGY}, author={RUFTY, TW and MACKOWN, CT and ISRAEL, DW}, year={1990}, month={Sep}, pages={328–333} }
 @article{rufty_volk_mcclure_israel_raper_1982, title={RELATIVE CONTENT OF NO3- AND REDUCED N IN XYLEM EXUDATE AS AN INDICATOR OF ROOT REDUCTION OF CONCURRENTLY ABSORBED N-150-3(-1)}, volume={69}, ISSN={["0032-0889"]}, DOI={10.1104/pp.69.1.166}, abstractNote={It is unclear if the relative content of NO(3) (-) and reduced N in xylem exudate provides an accurate estimate of the percentage reduction of concurrently absorbed NO(3) (-) in the root. Experiments were conducted to determine whether NO(3) (-) and reduced N in xylem exudate of vegetative, nonnodulated soybean plants (Glycine max [L.] Merr., ;Ransom') originated from exogenous recently absorbed (15)NO(3) (-) or from endogenous (14)N pools. Plants either were decapitated and exposed to (15)NO(3) (-) solutions for 2 hours or were decapitated for the final 20 minutes of a 50-minute exposure to (15)NO(3) (-) in the dark and in the light. Considerable amounts of (14)NO(3) (-) and reduced (14)N were transported into the xylem, but almost all of the (15)N was present as (15)NO(3) (-). Dissimilar changes in transport of (14)NO(3) (-), reduced (14)N and (15)NO(3) (-) during the 2 hours of sap collection resulted in large variability over time in the percentage of total N in the exudate which was reduced N. Over a 20-minute period the rate of (15)N transport into the xylem of decapitated plants was only 21 to 36% of the (15)N delivered to the shoot of intact plants. Based on the proportion of total (15)N which was found as reduced (15)N in exudate and in intact plants in the dark, it was estimated that 5 to 17% of concurrently absorbed (15)NO(3) (-) was reduced in the root. This was much less than the 38 to 59% which would have been predicted from the relative content of total NO(3) (-) and total reduced N in the xylem exudate.}, number={1}, journal={PLANT PHYSIOLOGY}, author={RUFTY, TW and VOLK, RJ and MCCLURE, PR and ISRAEL, DW and RAPER, CD}, year={1982}, pages={166–170} }