@article{akinrinlola_kelly_sinclair_shekoofa_2024, title={<i>Heterodera glycines</i> HG type 1.2.5.7 causes a decrease in soybean (<i>Glycine max</i> [L.] Merr.) nitrogen fixation and growth variables}, ISSN={["1542-7536"]}, DOI={10.1080/15427528.2024.2336267}, journal={JOURNAL OF CROP IMPROVEMENT}, author={Akinrinlola, Rufus J. and Kelly, Heather M. and Sinclair, Thomas R. and Shekoofa, Avat}, year={2024}, month={Apr} }
 @article{jafarikouhini_sinclair_2024, title={Recovery of root hydraulic conductance and xylem vessel diameter following prolonged water deficit of maize}, ISSN={["1435-0653"]}, DOI={10.1002/csc2.21161}, abstractNote={To sustain crop growth following soil water‐deficit, it is essential to have rapid recovery of leaf gas exchange. One basis for rapid recovery would be rapid return of root hydraulic conductance to predrought levels to support water transport to the plant shoot. In this study, transpiration and root hydraulic conductance were measured over a 7‐d recovery period following an initial water‐deficit treatment of three maize (Zea mays L.) cultivars. In addition, xylem vessel diameter was measured during the recovery period at different positions from the root tip. Initiation of recovery in transpiration rate occurred in all three cultivars within 3 days after watering, although root conductance and transpiration rate of one cultivar was much lower than the other two cultivars. Root conductance and vessel diameter increased more slowly than the recovery of transpiration. There was indication that transpiration could have been limited by root hydraulic conductance only when its values were low during recovery. The relationship between hydraulic conductance and vessel diameter did not, however, indicate a Poiseuille's law relationship between the two variables. Overall, cultivar variability in recovery from water deficit of transpiration rate and root hydraulic conductance indicates that selection for rapid recovery of leaf gas exchange following water deficit could be an important component of genotype selection in maize breeding programs.This article is protected by copyright. All rights reserved}, journal={CROP SCIENCE}, author={Jafarikouhini, Nahid and Sinclair, Thomas R.}, year={2024}, month={Jan} }
 @article{sinclair_jafarikouhini_pradhan_2024, title={Unexpectedly, triple super phosphate fertilizer induces maize drought resilience}, ISSN={["1532-4087"]}, DOI={10.1080/01904167.2024.2325948}, abstractNote={Phosphorus fertilizer is commonly applied to soils in crop production as diammonium phosphate (DAP). To decrease ammonium addition to the environment, triple super phosphate (TSP) is being considered as a DAP replacement. This study was undertaken to compare the response of maize plants to soil fertilization with TSP vs. DAP under well-watered conditions, under soil-drying conditions, and root hydraulic conductance. It was found for well-watered conditions in a controlled environment that there was no difference in plant growth between DAP to TSP treatments. In soil dry-down experiments, however, the initiation of the decrease in transpiration rate was unexpectedly quite different between DAP and TSP treatments. The soil water content threshold for initiation of decrease in transpiration rate with DAP treatment (average fraction transpirable soil water for two experiments = 0.285) was consistent with common observations, but the threshold associated with TSP treatment occurred at an unusually high soil water content (average fraction transpirable soil water for two experiments = 0.545). The higher threshold with TSP resulted in an extended period of soil water use, i.e. soil water conservation. Soil water conservation resulting from the TSP treatment was associated with a 27% greater shoot mass accumulation following a 4-wk re-watering period after the water-deficit treatment than measured with the DAP treatment. The high threshold for decrease in transpiration resulting from TSP was consistent with measured lower root hydraulic conductance as compared to DAP treatment. The unexpected discovery of TSP-induced initiation of transpiration rate decrease at high soil water content is consistent with greater crop drought resilience.}, journal={JOURNAL OF PLANT NUTRITION}, author={Sinclair, Thomas R. and Jafarikouhini, Nahid and Pradhan, Deepti}, year={2024}, month={Feb} }
 @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} }
 @article{jafarikouhini_sinclair_2023, title={Hydraulic conductance and xylem vessel diameter of young maize roots subjected to sustained water-deficit}, ISSN={["1435-0653"]}, DOI={10.1002/csc2.21023}, abstractNote={Abstract Water deficit can have large impacts on plants, including likely alteration of root hydraulic conductance and root xylem vessel diameter, which can decrease crop productivity. No results, however, exist to assess possible linkages between these two variables as critical components contributing to plant water status. This linkage was investigated in three maize ( Zea mays L.) cultivars. A stable water‐deficit treatment was established and maintained in pots by allowing soil drying to the point where transpiration rate was held constant at about 0.5 of well‐watered pots. Initially, the root hydraulic conductance of the water‐deficit plants was equivalent to that of well‐watered plants. Subsequently, however, hydraulic conductance decreased substantially. The results for xylem vessel diameter at 5 cm from the root tip exhibited a pattern similar to the decrease in root hydraulic conductance. A graph of root hydraulic conductance versus xylem vessel diameter at 5 cm showed a curvilinear response with lessening in the increase in hydraulic conductance with increasing xylem vessel diameter. The results indicate a possible link between root conductance and xylem diameter but the conductance is much less sensitive to vessel diameter than the fourth power of the radius predicted by Poiseuille's law. The association between conductance and xylem vessel diameter may reflect interaction of radial and axial water flux through the root system as indexed by vessel radius in the zone near the root tip.}, journal={CROP SCIENCE}, author={Jafarikouhini, Nahid and Sinclair, Thomas R.}, year={2023}, month={May} }
 @article{rouichi_idrissi_sohail_marrou_sinclair_hejjaoui_amri_ghanem_2023, title={Limited-transpiration trait in response to high vapor pressure deficit from wild to cultivated species: study of the Lens genus}, ISSN={["1460-2431"]}, DOI={10.1093/jxb/erad264}, abstractNote={Lentil (Lens culinaris Medik.) is commonly grown in drought-prone areas where terminal heat and drought are frequent. The limited transpiration trait (TRlim) under high vapor pressure deficit (VPD) could be a way to conserve water and increase yield under water deficit conditions. The TRlim trait was examined in cultivated and wild lentil species and its evolution throughout the selection pipeline. 61 accessions representing the six wild lentil species (L. orientalis, L. tomentosus, L. odemensis, L. lamottei, L. ervoides, and L. nigricans), and 13 interspecific advanced lines were evaluated in their transpiration response to high VPD. A large variation in transpiration rate (TR) response to increased VPD was recorded among wild lentil accessions with 43 accessions exhibiting a breakpoint (BP) in their TR response to increasing VPD with values ranging from 0.92 to 3.38 kPa under greenhouse conditions. Ten genotypes for the interspecific advanced lines displayed a BP with an average of 1.95 kPa, much lower than previously reported for cultivated lentil. Results from field experiments suggest that the TRlim trait (BP = 0.97 kPa) positively affected yield and yield-related parameters during the years with late-season water stress. The selection of TRlim genotypes for high VPD environments could improve lentil productivity in drought-prone areas.}, journal={JOURNAL OF EXPERIMENTAL BOTANY}, author={Rouichi, Salma and Idrissi, Omar and Sohail, Quahir and Marrou, Helene and Sinclair, Thomas R. and Hejjaoui, Kamal and Amri, Moez and Ghanem, Michel Edmond}, year={2023}, month={Jul} }
 @article{echarte_sinclair_jafarikouhini_2023, title={Maize leaf rolling and its response to drying soil and evaporative demand}, ISSN={["1435-0653"]}, DOI={10.1002/csc2.21002}, abstractNote={Abstract Leaf rolling is an adaptive mechanism associated with water deficiencies; however, the physiological processes and environmental factors contributing to leaf rolling are not fully understood. The objective of this study was to examine (i) a possible relationship between the degree of leaf rolling and soil water content and (ii) the possible influence of vapor pressure deficit (VPD) on the degree of leaf rolling. Leaf rolling was measured on maize ( Zea mays L.) plants grown in pots and subjected to various soil drying and atmospheric VPD treatments. The experimental results indicated that (i) high VPD by itself does not readily induce leaf rolling, and (ii) leaf rolling was observed in proportion to the extent of soil drying. The values of the fraction of transpirable soil water thresholds for the decline in normalized transpiration rate and for the initiation of plant leaf rolling were sensitive to environmental conditions (VPD and temperature). With soil drying, leaf rolling was initiated slightly after the initiation of a decrease in the transpiration rate.}, journal={CROP SCIENCE}, author={Echarte, Laura and Sinclair, Thomas. R. R. and Jafarikouhini, Nahid}, year={2023}, month={May} }
 @misc{sinclair_ghanem_abdel latef_yadav_2023, title={Realistic Physiological Options to Increase Grain Legume Yield under Drought}, volume={12}, ISSN={["2223-7747"]}, DOI={10.3390/plants12173137}, abstractNote={Increasing yield resiliency under water deficits remains a high priority for crop improvement. In considering the yield benefit of a plant trait modification, two facts are often overlooked: (1) the total amount of water available to a crop through a growing season ultimately constrains growth and yield cannot exceed what is possible with the limited amount of available water, and (2) soil water content always changes over time, so plant response needs to be considered within a temporally dynamic context of day-to-day variation in soil water status. Many previous evaluations of drought traits have implicitly considered water deficit from a “static” perspective, but while the static approach of stable water deficit treatments is experimentally congruous, the results are not realistic representations of real-world drought conditions, where soil water levels are always changing. No trait always results in a positive response under all drought scenarios. In this paper, we suggest two key traits for improving grain legume yield under water deficit conditions: (1) partial stomata closure at elevated atmospheric vapor pressure deficit that results in soil water conservation, and (2) lessening of the high sensitivity of nitrogen fixation activity to soil drying.}, number={17}, journal={PLANTS-BASEL}, author={Sinclair, Thomas R. and Ghanem, Michel E. and Abdel Latef, Arafat Abdel Hamed and Yadav, Narendra Singh}, year={2023}, month={Sep} }
 @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{jafarikouhini_sinclair_resende_2022, title={Comparison of water flow capacity in leaves among sweet corn genotypes as basis for plant transpiration rate sensitivity to vapor pressure deficit}, ISSN={["1435-0653"]}, DOI={10.1002/csc2.20711}, abstractNote={Abstract Genotypes in crop species have been identified that initiate partial stomata closure at elevated atmospheric vapor pressure deficit (VPD), which results in conserved soil water for crop use during subsequent water‐deficit episodes and thereby allowing for possible yield increase. In sweet corn ( Zea mays L), 17 genotypes have been previously identified with the VPD‐responsive trait, although the VPD value at the initiation of stomata closure varied among genotypes. A hypothesis to explain variation in transpiration response to VPD is that water flow capacity in the leaves differs among genotypes. To gauge water flow capacity in leaves, the rate of stomata opening was observed visually after stomata closure was induced by 3 kPa VPD. The stomata opening time was rapid and varied among genotypes from 90 to 179 s. However, there was no correlation between opening time and the VPD at which partial stomata closure was initiated in intact plants. An additional set of experiments was done to examine whether genotypic differences in a subpopulation of silver‐inhibited aquaporins might contribute to differences in leaf water flow. There was a correlation among genotypes between slow opening time of the stomata and greater inhibition of transpiration rate following feeding leaves with silver ion. However, the response to the silver treatment did not correlate with the VPD at which transpiration decrease of intact plants was initiated. These results indicate that the differences observed in the water flow capacity in sweet corn leaves were not major factors accounting for the genotypic differences in whole‐plant transpiration response to elevated VPD.}, journal={CROP SCIENCE}, author={Jafarikouhini, Nahid and Sinclair, Thomas R. and Resende, Marcio F., Jr.}, year={2022}, month={Feb} }
 @article{kibbou_el bouhmadi_marrou_sinclair_ghanem_2022, title={Impact of drought and temperature constraints on development and growth of faba bean (Vicia faba L.)}, volume={36}, ISSN={["1542-7536"]}, DOI={10.1080/15427528.2021.1906811}, abstractNote={ABSTRACT Faba bean (Vicia faba L.) is an important traditional pulse crop in many parts of Asia and the Mediterranean region. However, water deficit and temperature, two of the key variables associated with climate variability, can have major negative influences on the development and growth of faba bean. A series of experiments were conducted to study the potential impact of temperature and water deficit on several physiological processes among faba bean genotypes. Development of node number was determined to be dependent on temperature and was found to be essentially constant among genotypes with a value of 56°C accumulated temperature required for appearance of each node. Plant leaf area, which is important in crop carbon accumulation, was estimated by developing allometric relationships between plant leaf area and number of nodes. The coefficients of these relationships varied among genotypes. Water deficit was found to be critical in impacting plant transpiration and nitrogen fixation rates. The threshold for the decrease in transpiration rate with soil drying was found to range from a fraction of transpirable soil water (FTSW) from 0.22 to 0.60 among 12 genotypes, indicating a genetic resource for improving drought resilience. Results in comparing symbiotic nitrogen fixation on drying soil among genotypes also indicated genetic variation, with one genotype (WW4403/H) being especially drought tolerant. The results of these experiments identified important genotypic differences in sensitivity of specific physiological processes to temperature and water deficit, which can be exploited to improve faba bean resilience to these environmental variables.}, number={1}, journal={JOURNAL OF CROP IMPROVEMENT}, author={Kibbou, Fatimaezzhara and El Bouhmadi, Keltoum and Marrou, Helene and Sinclair, Thomas R. and Ghanem, Michel E.}, year={2022}, month={Jan}, pages={57–72} }
 @article{sinclair_jafarikouhini_2022, title={Plant waterflow restrictions among sweet corn lines related to limited-transpiration trait}, ISSN={["1435-0653"]}, DOI={10.1002/csc2.20717}, abstractNote={Abstract While partial stomata closure under elevated vapor pressure deficit (VPD), that is, a limited‐transpiration trait resulting in soil water conservation and crop drought resiliency, has been identified in a few lines in all major crop species, the basis for the trait is not resolved. Since changes in stomatal aperture are associated with hydraulic processes, properties influencing waterflow in the plant are candidates associated with expression of limited‐transpiration. In a previous study with leaves of sweet corn ( Zea mays L.), limited‐transpiration was only weakly associated with the effect of silver ion, an aquaporin inhibitor, on leaf transpiration rate. The hypothesis was explored that total aquaporin activity rather than only silver‐sensitive aquaporins may be more relevant in the expression of limited transpiration. Leaves were fed potent aquaporin inhibitors of mercury and peroxide which both resulted in greater transpiration inhibition than silver, but there were no differences in response among lines. A second hypothesis was that there may be a major limitation of waterflow in the root system accounting for genotypic variation in expression of the limited‐transpiration trait. No differences in root hydraulic conductance were found among sweet corn lines differing in the limited‐transpiration trait. However, it was discovered that the root conductance decreased during the photoperiod in all tested lines. Measurements of root hydraulic conductance in response to a silver treatment showed differences among lines with an association between the VPD breakpoint for limited transpiration and transpiration sensitivity to the silver treatment.}, journal={CROP SCIENCE}, author={Sinclair, Thomas R. and Jafarikouhini, Nahid}, year={2022}, month={Apr} }
 @article{sinclair_marrou_ghanem_kharrat_amri_2022, title={Review of quantitative sensitivity of faba bean physiology to temperature and soil-water deficit}, ISSN={["1836-5795"]}, DOI={10.1071/CP22316}, abstractNote={ABSTRACT Faba bean (Vicia faba L.) is an important component of cropping systems in cool, arid environments. However, no review has specifically focused on the quantitative sensitivity of physiological processes in faba bean to low temperature and water deficits. The objective of this review was to examine published functional relationships between physiological activity and these environmental variables. Among faba bean genotypes, temperature generally resulted in a consistent linear response in plant ontogeny and leaf area development. By contrast, nitrogen fixation exhibited a sharp threshold response to temperature such that at temperatures below ~13.5–15°C faba bean had virtually no nitrogen fixation activity. This inability to fix nitrogen under cool temperatures is likely to be a major weakness for faba bean in cool-season production systems. Water deficit also had a large impact on the physiology of faba bean. Ontogeny was generally shortened when plants were subjected to drought, resulting in major yield decreases. Genotypic differences within faba bean have been identified for initiation of partial stomata closure at high soil-water content, resulting in possible soil-water conservation in the field. Also, differences among genotypes have been identified in the sensitivity of nitrogen fixation activity to water deficits. Finally, collectively the reviewed functional relationships have been applied to simulation analysis of the geospatial impact of irrigation regimes and of sowing date for faba bean production. These geospatial studies offered insights on options to improve faba bean management.}, journal={CROP & PASTURE SCIENCE}, author={Sinclair, Thomas R. and Marrou, Helene and Ghanem, Michel Edmond and Kharrat, Mohamed and Amri, Moez}, year={2022}, month={Nov} }
 @article{sinclair_2021, title={"Basis of yield component compensation in crop plants with special reference to field bean, Phaseolus vulgaris" by M. Wayne Adams, Crop Science (1967) 7, 505-510}, volume={61}, ISSN={["1435-0653"]}, DOI={10.1002/csc2.20350}, abstractNote={Abstract This article is part of a series of brief commentaries to highlight papers that have resulted in important and distinctly new perspectives in crop science. A criterion for selection of papers is that they must have been published at least 20 yr ago to allow for a long‐range perspective in assessment of the papers. The current article briefly reviews the paper by M. Wayne Adams published in 1967 that provided original insights about compensation in the components of seed number and seed yield in determining crop yield. Adams reviewed experimental results in a large number of crop species and discovered a consistent negative correlation between seed number and mean seed mass. He labeled this negative correlation as “component compensation” in the formation of yield. He hypothesized that component compensation resulted from limiting nutrient‐metabolite availability to support developing reproductive structures. Ultimately, the retained seeds would be filled to the extent allowed by the supply of nutrient‐metabolites so that there was compensation between seed number and individual seed mass.}, number={2}, journal={CROP SCIENCE}, author={Sinclair, Thomas R.}, year={2021}, month={Mar}, pages={863–865} }
 @article{sinclair_2021, title={"Studies of the Uptake of Nitrate in Barley. I. Kinetics of (NO3-)-N-13 Influx" by MY Siddiqi, ADM Glass, TJ Ruth, and TW Rufty, Jr., Plant Physiology (1990) 93:1426-1432}, volume={61}, ISSN={["1435-0653"]}, DOI={10.1002/csc2.20287}, abstractNote={Abstract This article is part of a series of brief commentaries to highlight papers that have resulted in important and distinctly new perspectives in crop science. A criterion for selection of papers is that they must have been published at least 20 yr ago to allow for a long‐range perspective in assessment of the papers. The current article briefly reviews the paper by M.Y. Siddiqi, A.D.M. Glass, T.J. Ruth, and T.W. Rufty, Jr. published in 1990 that investigated the kinetics of nitrate influx by barley ( Hordeum vulgare L.) seedlings. Using 13 NO 3 − , they documented the existence of two influx systems. One was inducible and nitrate influx saturated under low nitrate concentrations. The second was noninducible and expressed a linear increase in nitrate influx over high nitrate concentrations. Key transformative results from this study were the demonstration that both systems were under negative feedback control based on root nitrate concentration.}, number={1}, journal={CROP SCIENCE}, author={Sinclair, Thomas R.}, year={2021}, month={Jan}, pages={21–23} }
 @article{guiguitant_marrou_vile_sinclair_pradhan_ramirez_ghanem_2021, title={An exploration of the variability of physiological responses to soil drying in relation with C/N balance across three species of the under-utilized genus Vigna}, volume={172}, ISSN={["1399-3054"]}, DOI={10.1111/ppl.13224}, abstractNote={The genus Vigna (Fabaceae) is an agriculturally important taxon, which includes several crop species such as cowpea (Vigna unguiculata L), mung bean (Vigna radiata) and azuki bean (Vigna angularis). Most studies have focused on cowpea (Vigna unguiculata (L.) as a drought-resistant crop, although insights on the mechanisms that confer this species the ability to grow in dry environment are still not fully resolved. The diversity of this rich genus has been overlooked in many physiological studies. This study explores the physiological mechanisms of response to soil drying (N2 fixation, transpiration rate and changes in C and N allocation) across three species of the Vigna genus: Vigna radiata, Vigna unguiculata, Vigna vexillata (tuber cowpea). A significant variability among the studied Vigna accessions was found for the threshold in decline of N2 fixation with soil drying. Less variability was observed in the transpiration threshold. Through the analysis of leaf traits variation under well-watered and water-deficit conditions, we were able to relate the variability in N2 fixation and transpiration response to C/N metabolism modifications resulting in different allocation of carbon and nitrogen to leaves under water deficit. This article is protected by copyright. All rights reserved.}, number={2}, journal={PHYSIOLOGIA PLANTARUM}, author={Guiguitant, Julie and Marrou, Helene and Vile, Denis and Sinclair, Thomas R. and Pradhan, Deepti and Ramirez, Martha and Ghanem, Michel Edmond}, year={2021}, month={Jun}, pages={477–486} }
 @article{kibbou_el bouhmadi_ghanem_marrou_sinclair_2021, title={Analysis for Improved Sowing Date for Winter Faba Bean in Morocco}, ISSN={["1735-8043"]}, DOI={10.1007/s42106-021-00162-4}, journal={INTERNATIONAL JOURNAL OF PLANT PRODUCTION}, author={Kibbou, Fatimaezzhara and El Bouhmadi, Keltoum and Ghanem, Michel E. and Marrou, Helene and Sinclair, Thomas R.}, year={2021}, month={Sep} }
 @article{chiango_figueiredo_sousa_sinclair_silva_2021, title={Assessing drought tolerance of traditional maize genotypes of Mozambique using chlorophyll fluorescence parameters}, volume={138}, ISSN={["1727-9321"]}, DOI={10.1016/j.sajb.2021.01.005}, abstractNote={Just behind wheat and rice, maize is the third most important grain crop in the world, grown in many agricultural areas. In Mozambique, rainfall is declining, posing serious threats to national food sovereignty and security, particularly in southern regions of the country. Despite this fact, few research studies have been conducted on the performance of Mozambique´s maize germplasm under drought stress conditions. A randomized design combining eight maize genotypes (six traditional Mozambican genotypes: LVA34, TCDE, G234, D456C, MABC, C123; and two commercial cultivars from DuPont Pioneer: P0023 and P9838) and three water regimes (control (irrigated), stress and recovery) was used to characterize the maize resilience to water deficit. The photochemical performance was accessed by rapid chlorophyll fluorescence induction curves (JIP-test). The use of Performance Index based dendrogram analysis allowed to explain genotypes behavior on the different experimental sets (control, drought stress and recovery). G234 and C123 presented the best performance with the lowest mortality rates, showing a better ability to cope with drought stress when compared to other genotypes from Mozambique and to the commercial cultivars from DuPont Pioneer.}, journal={SOUTH AFRICAN JOURNAL OF BOTANY}, author={Chiango, Hamilton and Figueiredo, Andreia and Sousa, Lisete and Sinclair, Thomas and Silva, Jorge Marques da}, year={2021}, month={May}, pages={311–317} }
 @article{chiango_jafarikouhini_pradhan_figueiredo_silva_sinclair_holland_2021, title={Drought resilience in CIMMYT maize lines adapted to Africa resulting from transpiration sensitivity to vapor pressure deficit and soil drying}, volume={8}, ISSN={["1542-7536"]}, DOI={10.1080/15427528.2021.1961334}, abstractNote={ABSTRACT Low rainfall limits crop yield, particularly for maize (Zea mays L.) in southern Africa. Consequently, there is a need to identify genetic sources of specific drought-related traits that can contribute to soil water conservation and increased yields under water-limited conditions. In this study, maize genotypes released for production in southern Africa were tested for expression of two soil water-conservation traits: limited transpiration under elevated vapor pressure deficit (VPD) and decreased transpiration rate at high soil water contents earlier in the soil drying cycle. Two genotypes, CML 590 and CML 593, were identified and confirmed to initiate expression of limited-transpiration rate at VPD above about 1.9 kPa. In the soil-drying experiment, Umbelu 8923 and Umbelu 8930 closed their stomata earliest in the soil drying cycle as compared to other tested genotypes. These four genotypes with specific physiological traits for superior response to water deficit are genetic resources for further study to improve maize drought resilience.}, journal={JOURNAL OF CROP IMPROVEMENT}, author={Chiango, H. and Jafarikouhini, N. and Pradhan, D. and Figueiredo, A. and Silva, J. and Sinclair, T. R. and Holland, J.}, year={2021}, month={Aug} }
 @article{jafarikouhini_kazemeini_sinclair_2021, title={Fresh sweet corn yield sensitivity to deficit nitrogen and water conditions}, ISSN={["1542-7536"]}, DOI={10.1080/15427528.2021.1995560}, abstractNote={ABSTRACT Water and nitrogen (N) are the major limitations for maximizing crop yield. However, there has been no detailed examination of these limitations on fresh kernel yield in sweet corn (Zea mays L.). A two-year field study in Shiraz, Iran, was conducted to document sweet corn response to three soil-water regimes (irrigation to field capacity, and 80% and 60% of this amount) and five N fertilizer amounts (0, 75, 125, 175, and 225 kg N ha−1). Decreasing irrigation to 60% of field capacity resulted in yield decreases. The results showed that increasing N amounts increased fresh kernel yield to a maximum at 175 and 225 kg N ha−1. A highly positive, linear correlation was found between fresh kernel yield and kernel number formed per ear (R2 = 0.94), and also between kernel fresh yield and total crop mass (R2 = 0.88). Harvest index (HI) based on dry kernel weight varied between 0.20 and 0.41 in the two years with the lowest HI occurring in the 0 and 75 kg N ha−1 treatments.}, journal={JOURNAL OF CROP IMPROVEMENT}, author={Jafarikouhini, Nahid and Kazemeini, Seyed Abdolreza and Sinclair, Thomas R.}, year={2021}, month={Oct} }
 @article{sinclair_jafarikouhini_2021, title={Interactive effects of level of nitrogen and irrigation application on maize yield}, ISSN={["1532-4087"]}, DOI={10.1080/01904167.2021.2020835}, abstractNote={Abstract Maize (Zea mays L.) yields are recognized to be sensitive to both the level of nitrogen fertilization and irrigation that is applied to the crop. However, there are virtually no studies where experimental results are analyzed to quantitatively explore directly the interactive influence of these two resources on yield. As a consequence, it is difficult to sort out the optimum management regime for the available resources. A polynomial regression analysis was applied to results from seven field experiments involving several nitrogen and irrigation treatments. The polynomial equation included for each resource a linear term and second-order term plus a multiplicative term of the two resources. The polynomial regression fit very well the results of all experiments (R2 ≥ 0.86). The impact of irrigation included the linear term in all experiments (p ≤ 0.017). In all but one experiment, yield was also linearly dependent on amount of nitrogen application. The polynomial expression led to determination of the nitrogen fertilization required for maximum yield as being dependent on level of irrigation. In all cases, increased irrigation amounts resulted in an increased nitrogen requirement to achieve maximum yield. Another important outcome of the analysis was that the multiplicative term for irrigation x nitrogen was generally important in describing yield. These results demonstrate the inadequacy of attempting to define the results of such multiple-factor experiments based on a single limiting-factor approach.}, journal={JOURNAL OF PLANT NUTRITION}, author={Sinclair, Thomas R. and Jafarikouhini, Nahid}, year={2021}, month={Dec} }
 @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{jafarikouhini_sinclair_resende_2021, title={Limited-transpiration rate and plant conductance in a diverse sweet corn population}, ISSN={["1435-0653"]}, DOI={10.1002/csc2.20664}, abstractNote={Abstract Limited‐transpiration rate at elevated vapor pressure deficit (VPD) can allow soil water conservation for use during late‐season drought, but it can also result in decreased crop yields under well‐watered conditions because of restricted crop gas exchange. Previous studies with sweet corn ( Zea mays L.) have found the limited‐transpiration rate was quite common among commercial cultivars even though sweet corn is commonly grown under well‐watered conditions. This study was undertaken to identify possible genetic sources of sweet corn that were not encumbered by the limited‐transpiration trait. Additionally, data were obtained to compare the plant hydraulic conductance among the lines. Among the 26 sweet corn lines included in this study, only eight did not express the limited‐transpiration trait. Four of the lines not expressing the limited‐transpiration (IL395a, IL543c, P39, and SD245) had stomata vapor conductance values over the range of tested VPD similar to the values expressed by many of the limited‐transpiration lines only at low VPD. The eight lines not expressing the limited‐transpiration trait tended to have low plant hydraulic conductance. For those lines expressing the limited‐transpiration trait, there was a correlation between the VPD at initiation of limited transpiration and plant hydraulic conductance. Expression of the limited‐transpiration traits proved, however, to be temperature sensitive in 7 of 18 tested lines expressing the trait at 32 °C because they failed to express the trait at 38 °C. The genetic variation in expression of the limited‐transpiration trait and plant hydraulic conductance identified in this study offers specific candidate inbred lines that could be used as genetic resources for improving sweet corn growth and yield for well‐watered environments.}, journal={CROP SCIENCE}, author={Jafarikouhini, Nahid and Sinclair, Thomas R. and Resende, Marcio F. R.}, year={2021}, month={Dec} }
 @article{pradhan_bertin_sinclair_nogueira_livingston_carter_2021, title={Microsphere stem blockage as a screen for nitrogen-fixation drought tolerance in soybean}, volume={172}, ISSN={["1399-3054"]}, DOI={10.1111/ppl.13281}, abstractNote={Symbiotic nitrogen fixation of soybean (Glycine max (Merr.) L) commonly decreases in response to soil drying in advance of other plant processes. While a few soybean lines express nitrogen fixation drought tolerance, breeding for genetic variation is hampered by laborious phenotyping procedures. The objective of this research was to explore the potential of an initial screen for nitrogen fixation drought-tolerant genotypes based on a possible relationship with xylem-vessel diameter. The hypothesis was that nitrogen fixation drought-tolerance might result from fewer, large-diameter xylem vessels in the stem that are vulnerable to disrupted flow as water deficit develops. The disrupted flow could cause nitrogen products to accumulate in nodules resulting in negative feedback on nitrogen fixation rate. The proposed screen involved exposing de-rooted shoots to a suspension containing microspheres (45-53 μm diameter) and recording the decrease in transpiration rate as a result of microsphere xylem-blockage. Two soybean populations were tested. One population was progeny derived from mating of two parents with high and low nitrogen fixation drought sensitivity. A high correlation (R2 = 0.68; P<0.001) was found in this population between decreasing transpiration rate resulting from the microsphere treatment and increasing sensitivity of nitrogen fixation to soil drying. The second tested population consisted of 16 genotypes, most of which had been previously identified in germplasm screens as expressing nitrogen fixation drought tolerance. Nearly half of the lines in this second population were identified in the screen as showing minimum blockage of transpiration when exposed to the microspheres. Overall, these results showed the potential of using the microsphere screen to identify candidate genotypes expressing nitrogen fixation drought-tolerance.}, number={2}, journal={PHYSIOLOGIA PLANTARUM}, author={Pradhan, Deepti and Bertin, Diana and Sinclair, Thomas R. and Nogueira, Marco A. and Livingston, David and Carter, Thomas}, year={2021}, month={Jun}, pages={1376–1381} }
 @article{marrou_ghanem_amri_maalouf_ben sadoun_kibbou_sinclair_2021, title={Restrictive irrigation improves yield and reduces risk for faba bean across the Middle East and North Africa: A modeling study}, volume={189}, ISSN={["1873-2267"]}, DOI={10.1016/j.agsy.2021.103068}, abstractNote={Faba bean is a crucial component of Mediterranean food systems. However, the crop is somewhat underrepresented in the major crop models and usage of these models requires substantial calibration with data that might not be available. The Simple Simulation Model (SSM) is a simple, non-calibrated and physiology-based model that has the advantage of having a reduced number of parameters that can all be measured or inferred from simple experiments. We aimed to parameterize and assess the capacity of the SSM to simulate faba bean phenology, dry matter accumulation, nitrogen accumulation and final yield and to explore the impact of supplemental irrigation on crop production. Model simulations were compared to observations collected over 30 experimental situations in Morocco, Tunisia, and Lebanon. SSM was then used to explore water restrictive irrigation scenarios, allowing two irrigation events after flowering, with a total irrigation dose of 50 mm, in the Middle East and in North Africa (MENA). The prediction error on final total above ground dry matter was satisfactory and the dynamics of dry matter and nitrogen accumulation in plant organs matched the observations. This study showed that 50 mm irrigation can be sufficient to substantially improve faba bean production sustainability in MENA. In the driest areas (below 200 mm in-season rainfall), 50 mm irrigation could reduce the risk of low crops by up to 34% and increase yield sufficiently to meet average farm household needs. In more humid areas of the region, 50 mm irrigation could improve faba bean yield by up to 1 t/ha compared to an average yield of 3.5 t/ha. Simulation outputs showed that deficit irrigation could improve N soil balance and soil health in the mid- to long-term. The analysis of the simulation results can be used to advise farmers on best adapted irrigation dates without additional in situ measurement. This study revealed that non-calibrated models such as SSM can simulate yield and dry matter accumulation with a predictive capacity similar to calibrated tools making it suitable for addressing a known gap in irrigation management for Mediterranean food systems. In the MENA region, relative small amounts of irrigation (50 mm) can substantially reduce production risk, and so increase security for farmers, and improve faba bean productivity and sustainability.}, journal={AGRICULTURAL SYSTEMS}, author={Marrou, Helene and Ghanem, Michel Edmond and Amri, Moez and Maalouf, Fouad and Ben Sadoun, Sarah and Kibbou, Fatimaezzhara and Sinclair, Thomas R.}, year={2021}, month={Apr} }
 @article{sanchez_sinclair_pradhan_2021, title={Transpiration response to vapor pressure deficit and soil drying among quinoa genotypes (Chenopodium quinoa Willd.)}, volume={35}, ISSN={["1542-7536"]}, DOI={10.1080/15427528.2020.1817221}, abstractNote={ABSTRACT Water-deficit conditions limit increasing crop yield around the world. In order to improve crop yield it has been proposed to decrease water use early in the season so more water will be available later in the season to support seed growth during reproductive development. To achieve this, there are two water-conservation traits of special interest: partial stomatal closure under high vapor pressure deficit (VPD) and early in the soil drying cycle. Quinoa (Chenopodium quinoa Willd.) is well known for its ability to grow in poor soils and extreme climatic environments. Therefore, quinoa may especially benefit from expression of water-conservation for water-limited conditions. These traits have not been previously studied in quinoa. This study reported the response of eight quinoa genotypes. Genotypes Red head, CICA-17, Salcedo, Ollague, Good Afternoon, and Pasankalla expressed a VPD breakpoint (BP) but Titicaca and French Vanilla not. All genotypes expressed a FTSW threshold with soil drying as expected. French Vanilla had the highest threshold, so it would be a candidate as a water-conserving genotype. The results of this study can be applied directly in field tests comparing cultivars under water-deficit conditions, and selection of genotypes to be used in breeding for improved cultivars specifically for drought.}, number={2}, journal={JOURNAL OF CROP IMPROVEMENT}, author={Sanchez, Maria and Sinclair, Thomas R. and Pradhan, Deepti}, year={2021}, month={Mar}, pages={291–302} }
 @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 This article is part of a series of brief commentaries to highlight papers that have resulted in important and distinctly new perspectives in crop science. A criterion for selection of papers is that they must have been published at least 20 yr ago to allow for a long‐range perspective in assessment of the papers. The current article briefly reviews the paper by H.D. Cooper and D.T. Clarkson published in 1989 that offered an original analysis of internal movement of nitrogen in wheat ( Triticum aestivum L.). Using 15 NO 3 − fed to a split‐root system, they found that a large fraction of absorbed nitrogen was rapidly cycled around the plant as a result of exchanges between the xylem and phloem. They concluded that cycling in the plant ensured tissues had access to a common pool of soluble nitrogen from which nitrogen could be removed and incorporated into protein depending on the demands of tissue growth. The cycling pool of nitrogen also provided a possible whole‐plant signaling mechanism that coordinates growth activities with the feedback control system regulating nitrate uptake by the root.}, number={5}, journal={CROP SCIENCE}, author={Rufty, Thomas W. and Sinclair, Thomas R.}, year={2020}, pages={2192–2194} }
 @article{sinclair_2020, title={"Water dynamics in the soil-plant-atmosphere system" by JT Ritchie, Plant and Soil (1981) 58:81-96}, volume={60}, ISSN={["1435-0653"]}, DOI={10.1002/csc2.20037}, abstractNote={Abstract}, number={2}, journal={CROP SCIENCE}, author={Sinclair, Thomas R.}, year={2020}, pages={541–543} }
 @article{shekoofa_sinclair_2020, title={Abscisic Acid and Sulfate Offer a Possible Explanation for Differences in Physiological Drought Response of Two Maize Near-Isolines}, volume={9}, ISSN={["2223-7747"]}, DOI={10.3390/plants9121713}, abstractNote={The hypothesis was tested that differences in response to water-deficits between low osmotic potential (LOP) and high osmotic potential (HOP) maize (Zea mays L.) near-isolines were associated with differences in transpiration rate sensitivity to abscisic acid (ABA) and/or sulfate. In a series of four experiments, decreases in transpiration rate (DTR) of whole plants and fully expanded leaves were measured in response to treatments of 1.0 µM ABA and 15 mM MgSO4 singly and in combination following long (2 day) and short (180 min) exposures. There was little evidence that intact plants grown on soil were responsive to the treatments. For hydroponically grown plants subjected to long exposure, there was similarly no response to treatments. Further, the short exposure of hydroponically grown plants to solely ABA or a combination of chemicals resulted in no sensitivity in DTR for either of the near-isolines. On the other hand, when these plants were fed sulfate, the transpiration was stimulated by about 20% for the LOP and 60% for the HOP. Detached leaves proved to be the most sensitive to treatment. Treatment with the two chemicals singly caused essentially equivalent DTR in the two near-isolines. However, treatment with ABA plus sulfate resulted in different DTR between the two near-isolines with values of 65% for the LOP and 16% for the HOP near-isoline. Overall, these results showed that the short exposure treatment of hydroponically grown plants or detached leaves supported the hypothesis of different transpiration rate sensitivities of the near-isolines in response to ABA and sulfate treatments.}, number={12}, journal={PLANTS-BASEL}, author={Shekoofa, Avat and Sinclair, Thomas R.}, year={2020}, month={Dec} }
 @article{jafarikouhini_pradhan_sinclair_2020, title={Basis of limited-transpiration rate under elevated vapor pressure deficit and high temperature among sweet corn cultivars}, volume={179}, ISBN={1873-7307}, DOI={10.1016/j.envexpbot.2020.104205}, abstractNote={One plant trait that has been developed in several crop species to increase the effectiveness in water use through the cropping season is limited-transpiration under elevated atmospheric vapor pressure deficit (VPD). This trait allows water conservation early in the season so that there is more soil water available late in the season for sustained physiological activity during seed development. In sweet corn (Zea mays L. saccharata), where the quality of the kernels is important, this trait could prove to be especially beneficial. The background objective of this study was to explore 16 sweet corn cultivars for expression of the limited-transpiration trait. It was found at 32 °C that 13 of the 16 cultivars expressed the trait. It was found in a subset of eight of these cultivars, however, only half retained the limited-transpiration trait at 38 °C. The additional objectives were to explore the hypotheses that expression of the limited-transpiration trait was related to plant hydraulic conductance, and to the abundance of silver-sensitive aquaporins in the leaves. In cultivars that lost expression of the limited-transpiration trait at 38 °C there were large increases in plant hydraulic conductance at 38 °C as compared to 32 °C. Abundance of silver-sensitive aquaporins was related to the transpiration rate under low VPD conditions. That is, those cultivars with more abundant silver-sensitive aquaporins had greater transpiration rates as a result of greater stomatal conductance. These results showed that while expression of the limited-transpiration trait in sweet corn at 32 °C was common, differences in expression of the trait at 38 °C were observed due to differences in plant hydraulic conductance and stomatal conductance.}, journal={ENVIRONMENTAL AND EXPERIMENTAL BOTANY}, author={Jafarikouhini, Nahid and Pradhan, Deepti and Sinclair, Thomas R.}, year={2020}, month={Nov} }
 @article{sinclair_soltani_marrou_ghanem_vadez_2020, title={Geospatial assessment for crop physiological and management improvements with examples using the simple simulation model}, volume={60}, ISSN={["1435-0653"]}, DOI={10.1002/csc2.20106}, abstractNote={Abstract}, number={2}, journal={CROP SCIENCE}, author={Sinclair, Thomas R. and Soltani, Afshin and Marrou, Helene and Ghanem, Michel and Vadez, Vincent}, year={2020}, pages={700–708} }
 @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{soltani_alimagham_nehbandani_torabi_zeinali_zand_ghassemi_vadez_sinclair_ittersum_2020, title={Modeling plant production at country level as affected by availability and productivity of land and water}, volume={183}, ISSN={["1873-2267"]}, DOI={10.1016/j.agsy.2020.102859}, abstractNote={Assessing the food availability and food security of countries is a critical exercise in which crop simulation models are essential. Application of crop models has been limited often to estimate yield per unit area of one or a few important field crops, whereas what is really required is the total national production of diverse crops including forages, vegetables and fruit trees that compete for limited resources of land and water. In this study a simple crop model (SSM-iCrop2; Simple Simulation Models) was set up for an entire country using a bottom-up approach such that it provides representative estimates of potential yield and other crop properties at provincial level as influenced by climate, soil, management and cultivar. The information is then used to calculate total plant production at province and country levels, as influenced by available land and water resources and by the efficiency of utilizing the resources using the concepts relative yield gap and irrigation efficiency. Iran was used as a case study to develop the modeling framework and illustrative outputs. Development of the framework resulted in accumulation of large bodies of valuable geospatial information and statistics across disciplines that are critical for analysis of plant production at a country level. The framework allows different scenarios of national plant production to be evaluated. This includes assessing the possibility of increasing national plant production via intensification, optimizing water allocation across plant species at province and country levels by changing the cropping pattern, and assessing and prioritizing possible ways of adapting a country's agriculture to limited land and water resources and climate change.}, journal={AGRICULTURAL SYSTEMS}, author={Soltani, A. and Alimagham, S. M. and Nehbandani, A. and Torabi, B. and Zeinali, E. and Zand, E. and Ghassemi, S. and Vadez, V. and Sinclair, T. R. and Ittersum, M. K.}, year={2020}, month={Aug} }
 @article{pradhan_dunne_ramirez_sinclair_2020, title={Nitrogen-fixation drought tolerance in virginia-type peanut}, volume={34}, ISSN={["1542-7536"]}, DOI={10.1080/15427528.2020.1740903}, abstractNote={ABSTRACT Symbiotic nitrogen-fixation activity of grain legumes commonly does not exhibit tolerance to soil drying, including in peanut (Arachis hypogaea L.). Since the demand for nitrogen of peanut is large in the synthesis of seeds with high protein concentration, loss of nitrogen-fixation activity can result in major yield decreases. The objective of this study was to search the germplasm of virginia-type peanut for sources of nitrogen-fixation drought tolerance. The first phase was a field screen in one growing season of 100 lines from which leaves were harvested and nitrogen concentration measured. Research in soybean had shown that low leaf-nitrogen concentration was associated with nitrogen-fixation drought tolerance. A wide range of leaf nitrogen concentrations was observed, and 10 lines of low leaf nitrogen (23.1 to 26.4 mg N g−1) were identified for the second phase of study. The second phase of study was done in a greenhouse with 5-week old plants sealed in pots subjected to a 2-week dry down. Each day, the plants were briefly exposed to acetylene to measure acetylene reduction activity as an indicator of nitrogen-fixation activity. The soil water content, at which a decline in nitrogen fixation was initiated, was not different among seven lines. Three of the lines exhibited high sensitivity of nitrogen fixation to soil drying. None of the lines, however, exhibited substantial tolerance of nitrogen fixation to soil drying, indicating a need to search an even more diverse population of peanut to identify a genetic source for tolerance.}, number={4}, journal={JOURNAL OF CROP IMPROVEMENT}, author={Pradhan, Deepti and Dunne, Jeffrey and Ramirez, Martha and Sinclair, Thomas R.}, year={2020}, month={Jul}, pages={540–548} }
 @misc{sinclair_ghanem_2020, title={Plant-based predictions of canopy transpiration instead of meteorological approximations}, volume={60}, ISSN={["1435-0653"]}, DOI={10.1002/csc2.20067}, abstractNote={Abstract}, number={3}, journal={CROP SCIENCE}, author={Sinclair, Thomas R. and Ghanem, Michel Edmond}, year={2020}, pages={1133–1141} }
 @article{manjarrez-sandoval_chen_mozzoni_florez-palacios_orazaly_wu_sinclair_carter_purcell_king_2020, title={Registration of soybean germplasm lines R10-2436 and R10-2710 with drought tolerance traits and high yield under moderate water stress}, volume={14}, ISSN={["1940-3496"]}, DOI={10.1002/plr2.20048}, abstractNote={Abstract Soybean [ Glycine max (L.) Merr.] lines R10‐2436 (Reg. no. GP‐439, PI 692971) and R10‐2710 (Reg. no. GP‐440, PI 692972) are high‐yielding and drought‐tolerant conventional germplasm released by the Arkansas Agricultural Experiment Station in February 2017. R10‐2436 and R10‐2710 have a relative maturity of 5.6 and 5.8, respectively. R10‐2436 is an F 4 –derived line from the cross R01‐52F × R02‐6268F, and R10‐2710 is an F 2 –derived line from R01‐52F × ‘USDA‐N7002’. In 6 yr of testing, R10‐2436 and R10‐2710 significantly outyielded the maturity group 5 check mean under moderate water‐deficit stress in Stuttgart, AR (2,893, 2,889, and 2,506 kg ha −1 , respectively) and were on a par with the checks under full irrigation in Stuttgart (4,644, 4,511, and 4,613 kg ha −1 , respectively) and in five additional irrigated Arkansas environments. The water‐deficit treatment consisted of normal irrigation until blooming, after which irrigation was suspended for the rest of the season. In greenhouse pot studies, both releases exhibited sustained nitrogen fixation during a dry‐down cycle. This trait was presumably inherited from their ancestor ‘Jackson’. R10‐2436 also exhibited slow wilting in multiple drought‐stressed environments in Arkansas and North Carolina, likely inherited from PI 416937. Because of their yield potential under drought and irrigation, as well as their good agronomic characteristics, R10‐2436 and R10‐2710 can be easily incorporated in applied breeding programs to transfer drought tolerance into elite high‐yielding cultivars.}, number={2}, journal={JOURNAL OF PLANT REGISTRATIONS}, author={Manjarrez-Sandoval, Pedro and Chen, Pengyin and Mozzoni, Leandro and Florez-Palacios, Liliana and Orazaly, Moldir and Wu, Chengjun and Sinclair, Thomas R. and Carter, Thomas E., Jr. and Purcell, Larry C. and King, C. Andy}, year={2020}, month={May}, pages={189–196} }
 @article{soltani_alimagham_nehbandani_torabi_zeinali_dadrasi_zand_ghassemi_pourshirazi_alasti_et al._2020, title={SSM-iCrop2: A simple model for diverse crop species over large areas}, volume={182}, ISSN={["1873-2267"]}, DOI={10.1016/j.agsy.2020.102855}, abstractNote={Crop models are essential in undertaking large scale estimation of crop production of diverse crop species, especially in assessing food availability and climate change impacts. In this study, an existing model (SSM, Simple Simulation Models) was adapted to simulate a large number of plant species including orchard species and perennial forages. Simplification of some methods employed in the original model was necessary to deal with limited data availability for some of the plant species to be simulated. The model requires limited, readily available input information. The simulations account for plant phenology, leaf area development and senescence, dry matter accumulation, yield formation, and soil water balance in a daily time step. Parameterization of the model for new crops/cultivars is easy and straight-forward. The resultant model (SSM-iCrop2) was parameterized and tested for more than 30 crop species of Iran using numerous field experiments. Tests showed the model was robust in the predictions of crop yield and water use. Root mean square of error as percentage of observed mean for yield was 18% for grain field crops, 14% for non-grain crops 14% for vegetables and 28% for fruit trees.}, journal={AGRICULTURAL SYSTEMS}, author={Soltani, A. and Alimagham, S. M. and Nehbandani, A. and Torabi, B. and Zeinali, E. and Dadrasi, A. and Zand, E. and Ghassemi, S. and Pourshirazi, S. and Alasti, O. and et al.}, year={2020}, month={Jun} }
 @article{ghanem_kehel_marrou_sinclair_2020, title={Seasonal and climatic variation of weighted VPD for transpiration estimation}, volume={113}, ISSN={["1873-7331"]}, DOI={10.1016/j.eja.2019.125966}, abstractNote={Vapor pressure deficit (VPD) is one of the critical variables that drives evapotranspiration, and is of fundamental importance in crop physiology and modeling in the face of climate change. Unfortunately, direct records of atmospheric moisture are rarely available at short temporal scales, e.g. hourly, and country or regional scales. Most models use approximations to estimate daily transpiration-weighted VPD. Tanner and Sinclair (1983) suggested an approach to calculate weighted daily VPD as a fraction (0.75) of the difference between daily maximum and minimum vapor pressure based on estimates calculated from daily maximum and minimum temperatures, respectively. A test of the Tanner-Sinclair suggestion is reported by obtaining daily weighted VPD from hourly measurements of humidity and temperature. The objective of this study was to assess the fractional value to obtained daily weighted VPD estimations. This study was based on ten years of hourly weather data collected at thirty five stations across the wide diversity of environments that exist in France.}, journal={EUROPEAN JOURNAL OF AGRONOMY}, author={Ghanem, Michel Edmond and Kehel, Zakaria and Marrou, Helene and Sinclair, Thomas R.}, year={2020}, month={Feb} }
 @article{schoppach_sinclair_sadok_2020, title={Sleep tight and wake-up early: nocturnal transpiration traits to increase wheat drought tolerance in a Mediterranean environment}, volume={47}, ISSN={["1445-4416"]}, DOI={10.1071/FP20044}, abstractNote={
In wheat, night-time transpiration rate (TRN) could amount to 14–55% of daytime transpiration rate (TR), depending on the cultivar and environment. Recent evidence suggests that TRN is much less responsive to soil drying than daytime TR, and that such ‘wasteful’ water losses would increase the impact of drought on yields. In contrast, other evidence indicates that pre-dawn, circadian increases in TRN may enable enhanced radiation use efficiency, resulting in increased productivity under water deficit. Until now, there have been no attempts to evaluate these seemingly conflicting hypotheses in terms of their impact on yields in any crop. Here, using the Mediterranean environment of Tunisia as a case study, we undertook a simulation modelling approach using SSM-Wheat to evaluate yield outcomes resulting from these TRN trait modifications. TRN represented 15% of daytime TR-generated yield penalties of up to 20%, and these worsened when TRN was not sensitive to soil drying TR. For the same TRN level (15%), simulating a predawn increase in TRN alleviated yield penalties, leading to yield gains of up to 25%. Overall, this work suggests that decreasing TRN but increasing pre-dawn circadian control would be a viable breeding target to increase drought tolerance in a Mediterranean environment.
}, number={12}, journal={FUNCTIONAL PLANT BIOLOGY}, author={Schoppach, Remy and Sinclair, Thomas R. and Sadok, Walid}, year={2020}, pages={1117–1127} }
 @article{jafarikouhini_kazemeini_sinclair_2020, title={Sweet corn nitrogen accumulation, leaf photosynthesis rate, and radiation use efficiency under variable nitrogen fertility and irrigation}, volume={257}, ISSN={["1872-6852"]}, DOI={10.1016/j.fcr.2020.107913}, abstractNote={Virtually no information exists on the response of sweet corn (Zea mays L. saccharata) to nitrogen fertility and irrigation treatments in terms of leaf nitrogen accumulation and the consequent impact on leaf CO2 assimilation rate and on crop growth as measured as radiation use efficiency (RUE). A two-year field experiment was undertaken in which a sweet corn cultivar was subjected to all combinations of five nitrogen fertility and three irrigation treatments. Leaf photosynthesis measurements were made at stages of 7–9 leaves, tasseling, silking, blistering, and milking. Leaf nitrogen per unit area was also measured at these five stages plus two additional stages before and after the five core measurements. Total nitrogen and plant mass was accumulated at the seven stages to track total nitrogen accumulation and to calculate RUE. The overall patterns in the measured variables were similar to those reported for field maize. However, leaf nitrogen per unit area for sweet corn under optimum conditions was greater than reported for field maize. The higher leaf nitrogen per unit area in sweet corn did not, however, result in greater leaf photosynthesis rates and RUE than reported for field maize. The results of these unique observations on sweet corn indicate the possibility of greater nitrogen storage in sweet corn leaves that is not directly linked with photosynthesis and carbon accumulation.}, journal={FIELD CROPS RESEARCH}, author={Jafarikouhini, Nahid and Kazemeini, Seyed Abdolreza and Sinclair, Thomas R.}, year={2020}, month={Oct} }
 @article{beseli_shekoofa_ali_sinclair_2020, title={Temporal water use by two maize lines differing in leaf osmotic potential}, volume={60}, ISSN={["1435-0653"]}, DOI={10.1002/csc2.20062}, abstractNote={Abstract}, number={2}, journal={CROP SCIENCE}, author={Beseli, Amber L. and Shekoofa, Avat and Ali, Mujahid and Sinclair, Thomas R.}, year={2020}, pages={945–953} }
 @article{ye_song_schapaugh_ali_sinclair_riar_raymond_li_vuong_valliyodan_et al._2020, title={The importance of slow canopy wilting in drought tolerance in soybean}, volume={71}, ISSN={["1460-2431"]}, DOI={10.1093/jxb/erz150}, abstractNote={Physiological mechanisms of slow canopy wilting in early maturity group soybeans were identified and the underlying QTLs were mapped and confirmed to protect soybean yield under drought in the field.}, number={2}, journal={JOURNAL OF EXPERIMENTAL BOTANY}, author={Ye, Heng and Song, Li and Schapaugh, William T. and Ali, Liakat and Sinclair, Thomas R. and Riar, Mandeep K. and Raymond, Raymond N. and Li, Yang and Vuong, Tri and Valliyodan, Babu and et al.}, year={2020}, month={Jan}, pages={642–652} }
 @article{nogueira_livingston_tuong_sinclair_2020, title={Xylem vessel radii comparison between soybean genotypes differing in tolerance to drought}, volume={34}, ISSN={["1542-7536"]}, DOI={10.1080/15427528.2020.1724225}, abstractNote={ABSTRACT Xylem element radius can be a key factor in determining plant hydraulic conductance and vulnerability to cavitation. Most studies of xylem element radius have been on woody species with a focus on plant survival under severe water-deficit stress. However, xylem element radius, particularly the largest radius elements, can potentially have an influence on hydraulic flow at more moderate water-deficits. Few studies have offered a detailed distribution of xylem element radii, and even fewer on the distribution in crop species. In this study, the xylem element radii of two genotypes of soybean (Glycine max L. Merr.) were compared because these two genotypes had been documented to react differently to drying soil. The stems of young plants were harvested from three positions, and in stem cross-sections, the number of xylem elements and the radius of each element were determined. While the number of xylem elements did not differ significantly between the two genotypes, the distribution of the radii was skewed to smaller radii in drought-tolerant PI 4719386 as compared to Hutcheson. This contrast extended to a difference between the genotypes in the radii of the largest elements, which are considered most vulnerable to cavitation.}, number={3}, journal={JOURNAL OF CROP IMPROVEMENT}, author={Nogueira, Marco and Livingston, David and Tuong, Tan and Sinclair, Thomas R.}, year={2020}, month={May}, pages={404–413} }
 @article{sinclair_2019, title={"A Model for Simulating Photosynthesis in Plant Communities" by WG Duncan, RS Loomis, WA Williams, and R. Hanau, Hilgardia (1967) 38: 181-205}, volume={59}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2018.07.0467}, abstractNote={This article is part of a series of brief commentaries to highlight papers that have resulted in important and distinctly new perspectives in crop science. A criterion for selection of papers is that they must have been published at least 20 yr ago to allow for a long‐range perspective in assessment of the papers. The current article briefly reviews the paper by W.G. Duncan, R.S. Loomis, W.A. Williams, and R. Hanau published in 1967 that provided original concepts about the interception of solar radiation by crop leaf canopies and the estimate of canopy photosynthesis rate based on the intercepted radiation. They developed a geometric description of beam penetration through leaf layers and calculation of canopy CO2 exchange by considering separately leaves in direct‐beam radiation and in the shade.}, number={1}, journal={CROP SCIENCE}, author={Sinclair, Thomas R.}, year={2019}, pages={15–18} }
 @article{sinclair_2019, title={"Natural Evaporation from Open Water, Bare Soil and Grass" by Harold L. Penman, Proceedings of the Royal Society of London (1948) A193:120-146}, volume={59}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2019.05.0292}, abstractNote={ABSTRACT}, number={6}, journal={CROP SCIENCE}, author={Sinclair, Thomas R.}, year={2019}, pages={2297–2299} }
 @article{sinclair_2019, title={"The Biological Yield and Harvest Index of Cereals as Agronomic and Plant Breeding Criteria" by CM Donald and J. Hamblin, Advances in Agronomy (1976) 28: 361-405}, volume={59}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2018.10.0645}, abstractNote={This article is part of a series of brief commentaries to highlight papers that have resulted in important and distinctly new perspectives in crop science. A criterion for selection of papers is that they must have been published at least 20 yr ago to allow for a long‐range perspective in assessment of the papers. The current article briefly reviews the paper by C.M. Donald and J. Hamblin published in 1976 that provided original insights about the role of harvest index (defined by them as the ratio of economic yield to aboveground mass) in influencing crop yield. Donald and Hamblin reviewed experimental results showing that harvest index was relatively stable across variations in plant size, had high heritability, and was associated with high grain yield. Although their observations were confirmed in subsequent tests, inconsistent results in plant selection in breeding programs for high yield based on harvest index has discouraged the use of harvest index as a basis for selection. Nevertheless, high harvest index is now well ingrained as an essential plant characteristic for high crop yields.}, number={3}, journal={CROP SCIENCE}, author={Sinclair, Thomas R.}, year={2019}, pages={850–852} }
 @misc{lemaire_sinclair_sadras_belanger_2019, title={Allometric approach to crop nutrition and implications for crop diagnosis and phenotyping. A review}, volume={39}, ISSN={["1773-0155"]}, DOI={10.1007/s13593-019-0570-6}, abstractNote={Historically, the agronomic focus of crop mineral nutrition has yielded responses to individual elements (N, P, K…) to determine the economically optimum fertilization rates. This “prognostic” approach required several parameters for crops, climates, and soils that are often estimated with large uncertainty leading to over-fertilization and environmental problems in some systems (e.g., maize in China), and under-fertilization and soil mining in other systems (e.g., wheat in Australia). In this review, an alternative approach is developed for reducing the uncertainty intrinsically linked to this prognostic approach. Our approach is based on four propositions: (1) the evidence of an allometry between the metabolic shoot mass (scaling with leaf area) and the structural shoot mass (supporting and vascular tissues) within plants that allows the formulation of critical N dilution curves and the determination of the Nitrogen Nutrition Index (NNI) for estimating the N nutrition status of field crops; (2) the co-regulation of crop N uptake dynamics by both soil N supply and crop N demand in relation with its growth capacity that allows a better, more generalizable estimation of timing and rate of fertilizer; (3) a better understanding of the effects of genotype–environment–management interactions on N use efficiency in cropping systems reducing then drastically uncertainties linked to the classical prognostic approach for N fertilization; (4) as P and K also relate allometrically with biomass, P and K concentrations can be directly related to N concentration for the formulation of a multi-element diagnosis of crop nutrition. Here, we develop the theoretical background supporting these four propositions and outline implications for both fertilization management and crop phenotyping.}, number={2}, journal={AGRONOMY FOR SUSTAINABLE DEVELOPMENT}, author={Lemaire, Gilles and Sinclair, Thomas and Sadras, Victor and Belanger, Gilles}, year={2019}, month={Apr} }
 @article{lemaire_sinclair_sadras_belanger_2019, title={Allometric approach to crop nutrition and implications for crop diagnosis and phenotyping. A review (vol 39, 27, 2019)}, volume={39}, ISSN={["1773-0155"]}, DOI={10.1007/s13593-019-0578-y}, abstractNote={Due to a different interpretation of a query about figure numbering during proof stage, figures and captions in above mentioned article got mixed-up in the final version.}, number={3}, journal={AGRONOMY FOR SUSTAINABLE DEVELOPMENT}, author={Lemaire, Gilles and Sinclair, Thomas and Sadras, Victor and Belanger, Gilles}, year={2019}, month={Jun} }
 @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{clavijo michelangeli_ricaurte_sinclair_rao_beebe_2019, title={Influence of plant density and growth habit of common bean on leaf area development and N accumulation}, volume={33}, ISSN={["1542-7536"]}, DOI={10.1080/15427528.2019.1644694}, abstractNote={ABSTRACT Crop yield requires leaf area to intercept solar radiation and to undertake photosynthesis, both of which depend on nitrogen (N) accumulation. Further, the amount of accumulated plant N at the beginning of seed fill serves as the reservoir for N required in synthesizing the proteins in developing seeds. For common bean (Phaseolus vulgaris L.), resolution of the basic characteristics limiting production is challenging because of variation in plant growth-habit and in wide-ranging plant spacing. Field experiments were undertaken at two low-latitude locations with three plant growth-habit types and six plant densities to measure canopy leaf area and leaf N accumulation at the beginning of seed fill. Plant spacing of 20 plants m−2 or more was sufficient to result in equal leaf area and N accumulation for all six plant genotypes at each location. However, the low-altitude, higher-temperature location had lower accumulated leaf N and yield than the high-altitude, cooler-temperature location. These results indicate attention needs to be given to physiological or agronomic approaches to overcome the negative impact of high temperature on N accumulation by common bean.}, number={5}, journal={JOURNAL OF CROP IMPROVEMENT}, author={Clavijo Michelangeli, Jose A. and Ricaurte, Jaumer and Sinclair, Thomas R. and Rao, Idupulapati M. and Beebe, Stephen E.}, year={2019}, month={Sep}, pages={620–632} }
 @article{sciarresi_patrignani_soltani_sinclair_lollato_2019, title={Plant Traits to Increase Winter Wheat Yield in Semiarid and Subhumid Environments}, volume={111}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2018.12.0766}, abstractNote={Core Ideas
Wheat simulations occurred in over 2000 site–years for semiarid and subhumid climates.Limited transpiration trait increased wheat yield in 12 g m−2 in semiarid climate.Root exploration traits improved wheat yield by 60 g m−2 in semiarid climate.Faster leaf development trait increased wheat yield by 21 g m−2 across the entire study‐regionGenetic variability exists for the above traits for breeding programs to explore.
}, number={4}, journal={AGRONOMY JOURNAL}, author={Sciarresi, Cintia and Patrignani, Andres and Soltani, Afshin and Sinclair, Thomas and Lollato, Romulo P.}, year={2019}, pages={1728–1740} }
 @misc{ewel_schreeg_sinclair_2019, title={Resources for Crop Production: Accessing the Unavailable}, volume={24}, ISSN={["1878-4372"]}, DOI={10.1016/j.tplants.2018.10.008}, abstractNote={Natural ecosystems and undomesticated plants have solved many resource-acquisition problems – problems challenging agriculture with economic and societal constraints on fertilizer, water and fossil energy. Symbiotic N2 fixation input can best be enhanced by focus on host plant. Biologically mediated extraction of phosphate from soils is widespread – geographically and phylogenetically – in nature. Efficacy of water use can be increased by temporal regulation of transpiration, by deeper-rooted crops, and by hydraulic redistribution via roots from wetter to drier soil where it can become available to companion species. An acute imbalance between human population and food production is projected, partially due to increasing resource scarcity; dietary shifts and the current course of technology alone will not soon solve the problem. Natural ecosystems, typically characterized by high species richness and perennial growth habit, have solved many of the resource–acquisition problems faced by crops, making nature a likely source of insights for potential application in commercial agriculture. Further research on undomesticated plants and natural ecosystems, and the adaptations that enable them to meet their needs for N, P, and water, could change the face of commercial food production, including on marginal lands. An acute imbalance between human population and food production is projected, partially due to increasing resource scarcity; dietary shifts and the current course of technology alone will not soon solve the problem. Natural ecosystems, typically characterized by high species richness and perennial growth habit, have solved many of the resource–acquisition problems faced by crops, making nature a likely source of insights for potential application in commercial agriculture. Further research on undomesticated plants and natural ecosystems, and the adaptations that enable them to meet their needs for N, P, and water, could change the face of commercial food production, including on marginal lands.}, number={2}, journal={TRENDS IN PLANT SCIENCE}, author={Ewel, John J. and Schreeg, Laura A. and Sinclair, Thomas R.}, year={2019}, month={Feb}, pages={121–129} }
 @article{beseli_hall_manandhar_sinclair_2019, title={Root osmotic potential and length for two maize lines differing in leaf osmotic potential}, volume={33}, ISSN={["1542-7536"]}, DOI={10.1080/15427528.2019.1607642}, abstractNote={ABSTRACT Two maize (Zea mays L.) lines had previously been developed, one for expression in leaves of high osmotic adjustment (HOA) and the other for low osmotic adjustment (LOA). In field, these lines differed in soil water extraction depth and in plant wilting. It was hypothesized that HOA in leaves was also expressed in the root tips, and consequently it results in greater root extension and extraction of deeper soil water. Experiments reported here were undertaken in 1-m tall pots in a growth chamber and in the field to test these hypotheses. Periodic harvests of the soil columns during dry-down experiments showed no leaf OA in the two maize lines although the HOA line consistently had a lower leaf osmotic potential than the LOA line by 0.23 MPa. On the other hand, under the slow development of water deficit there was equivalent root tip OA in both lines. Consistent with this equivalency in root tip OA, no consistent difference in root length was observed in any of the experiments. Hence, the basis for the difference in wilting and water use between the two maize lines was not explained by differences in root OA and root extension.}, number={4}, journal={JOURNAL OF CROP IMPROVEMENT}, author={Beseli, Amber and Hall, Antonio J. and Manandhar, Anju and Sinclair, Thomas R.}, year={2019}, month={Jul}, pages={429–444} }
 @article{pradhan_shekoofa_sinclair_2019, title={Temperature effect on peanut (Arachis hypogaea L.) transpiration response to vapor pressure deficit and its recovery}, volume={33}, ISSN={["1542-7536"]}, DOI={10.1080/15427528.2018.1552900}, abstractNote={ABSTRACT Partial stomata closure under high atmospheric vapor pressure deficit (VPD) has been identified as a means to conserve soil water to allow sustained crop physiological activity late in the growing season, especially during reproductive growth. This trait has been identified as potentially being particularly important in peanut (Arachis hypogaea L.) since peanut is commonly grown on sandy soils under variable rainfall conditions. While 11 peanut genotypes had been previously identified as expressing limited-transpiration trait (TRlim) at 32°C, there is no information on their response to VPD at higher temperatures to which peanut may be exposed. This study documented the response of these 11 genotypes to VPD when subjected to increasing temperatures at 2°C intervals from 32°C to 38°C. Nine of the 11 genotypes lost expression of the TRlim trait within this temperature range. Only two genotypes (N013042ol and G644) were able to sustain the TRlim trait at 38°C. Recovery of expression of the TRlim trait following the loss of the trait at high temperature also varied among genotypes. Three genotypes that lost expression of TRlim at 36°C were returned to 32°C to determine the ability to recover the trait. Two genotypes showed full recovery of TRlim within 1 or 2 days, whereas the third showed no recovery across 3 days. This study provides useful information on genotypic variability in transpiration response to VPD under high temperatures that can be applied in developing cultivars that are better suited to water-limited conditions.}, number={2}, journal={JOURNAL OF CROP IMPROVEMENT}, author={Pradhan, Deepti and Shekoofa, Avat and Sinclair, Thomas R.}, year={2019}, month={Mar}, pages={177–186} }
 @article{livingston_tuong_nogueira_sinclair_2019, title={Three-dimensional reconstruction of soybean nodules provides an update on vascular structure}, volume={106}, ISSN={["1537-2197"]}, DOI={10.1002/ajb2.1249}, abstractNote={Premise of the StudyIn many cases, the functioning of a biological system cannot be correctly understood if its physical anatomy is incorrectly described. Accurate knowledge of the anatomy of soybean [Glycine max (L.) Merril] nodules and its connection with the root vasculature is important for understanding its function in supplying the plant with nitrogenous compounds. Previous two‐dimensional anatomical observations of soybean nodules led to the assumption that vascular bundles terminate within the cortex of the nodule and that a single vascular bundle connects the nodule to the root. We wanted to see whether these anatomical assumptions would be verified by digitally reconstructing soybean nodules in three dimensions.}, number={3}, journal={AMERICAN JOURNAL OF BOTANY}, author={Livingston, David and Tuong, Tan and Nogueira, Marco and Sinclair, Thomas}, year={2019}, month={Mar}, pages={507–513} }
 @article{steketee_sinclair_riar_schapaugh_li_2019, title={Unraveling the genetic architecture for carbon and nitrogen related traits and leaf hydraulic conductance in soybean using genome-wide association analyses}, volume={20}, ISSN={["1471-2164"]}, DOI={10.1186/s12864-019-6170-7}, abstractNote={Abstract}, number={1}, journal={BMC GENOMICS}, author={Steketee, Clinton J. and Sinclair, Thomas R. and Riar, Mandeep K. and Schapaugh, William T. and Li, Zenglu}, year={2019}, month={Nov} }
 @article{sadok_schoppach_ghanem_zucca_sinclair_2019, title={Wheat drought-tolerance to enhance food security in Tunisia, birthplace of the Arab Spring}, volume={107}, ISSN={["1873-7331"]}, DOI={10.1016/j.eja.2019.03.009}, abstractNote={The beginning of the ‘Arab Spring’ in 2011, a regional revolution which started in the Tunisian city of Sidi Bouzid in late 2010, occurred in part as a result of drought-triggered high wheat prices, which in the past led to ‘bread riots’ across several Middle East and North Africa (MENA) nations. Here we present, for the first time, an analysis of possible amelioration of wheat yield loss and greater stability in bread supply resulting from the incorporation of putative drought-tolerant traits into wheat cultivars grown in Tunisia. To this end, we used a simulation crop modeling approach using SSM-Wheat to evaluate yield loss or gain resulting from three types of water-saving traits that have been recently identified in wheat. These consisted in partial stomatal closure at high soil water content, overall decrease in transpiration rate (TR), and partial stomatal closure under elevated vapor pressure deficit (VPD). To capture large gradients in seasonal precipitation across wheat growing areas over a small country such as Tunisia, a grid pattern of 29 × 29 km was established as a basis for the geospatial simulation. Surprisingly, the simulation reflected opposite strategies in terms of water use (water-saving vs aggressive water use). The highest yield gain (30%) resulting from water-saving modification was found to occur in the food-insecure region of Sidi Bouzid. Traits enabling aggressive water use were found to be generally favorable across Tunisia, with one trait leading to up to 80% and 40% increases in yield and its stability in the food-challenged south of the country. However, major yield penalties were found to occur if water-saving traits were to be deployed in the ‘wrong’ region. Those findings could be used as a blueprint to navigate complex trait × environment interactions and to better inform local breeding and management programs to improve wheat yield and it stability in Tunisia and the MENA region in general.}, journal={EUROPEAN JOURNAL OF AGRONOMY}, author={Sadok, Walid and Schoppach, Remy and Ghanem, Michel E. and Zucca, Claudio and Sinclair, Thomas R.}, year={2019}, month={Jul}, pages={1–9} }
 @article{sinclair_2018, title={"A Biometeorological Time Scale for Cereal Crop Involving Day and Night Temperatures and Photoperiod" by George W. Robertson, International Journal of Biometeorology (1968) 12:191-223}, volume={58}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2018.05.0289}, abstractNote={This article is part of a series of brief commentaries to highlight papers that have resulted in important and distinctly new perspectives in crop science. A criterion for the selection of papers is that they must have been published at least 20 yr ago to allow for a long‐range perspective in assessment of the papers. The current article briefly reviews the paper by George Robertson published in 1968 that provided key concepts used yet today to describe the pace of plant development. Robertson developed the ideas of normalized development rates for each ontogenetic stage, multiplication of temperature and photoperiod responses, and inclusion of base temperature and photoperiod parameters in the response functions.}, number={6}, journal={CROP SCIENCE}, author={Sinclair, Thomas R.}, year={2018}, pages={2229–2232} }
 @misc{shekoofa_sinclair_2018, title={Aquaporin Activity to Improve Crop Drought Tolerance}, volume={7}, ISSN={["2073-4409"]}, DOI={10.3390/cells7090123}, abstractNote={In plants, aquaporins (AQP) occur in multiple isoforms in both plasmalemma and tonoplast membranes resulting in regulation of water flow in and out of cells, and ultimately, water transfer through a series of cells in leaves and roots. Consequently, it is not surprising that physiological and molecular studies have identified AQPs as playing key roles in regulating hydraulic conductance in roots and leaves. As a result, the activity of AQPs influences a range of physiological processes including phloem loading, xylem water exit, stomatal aperture and gas exchange. The influence of AQPs on hydraulic conductance in plants is particularly important in regulating plant transpiration rate, particularly under conditions of developing soil water-deficit stress and elevated atmospheric vapor pressure deficit (VPD). In this review, we examine the impact of AQP activity and hydraulic conductance on crop water use and the identification of genotypes that express soil water conservation as a result of these traits. An important outcome of this research has been the identification and commercialization of cultivars of peanut (Arachis hypogaea L.), maize (Zea mays L.), and soybean (Glycine max (Merr) L.) for dry land production systems.}, number={9}, journal={CELLS}, author={Shekoofa, Avat and Sinclair, Thomas R.}, year={2018}, month={Sep} }
 @article{sinclair_2018, title={Effective Water Use Required for Improving Crop Growth Rather Than Transpiration Efficiency}, volume={9}, ISSN={["1664-462X"]}, DOI={10.3389/fpls.2018.01442}, abstractNote={The phenomenological expression showing crop yield to be directly dependent on crop transpiration use efficiency (TE) has encouraged continued focus on TE as a viable approach to increasing crop yields. The difficulty in the phenomenological perspective is that research tends not to match up with the underlying mechanistic variables defining TE. Experimental evidence and the mechanistic derivation of TE by Tanner and Sinclair showed that the common focus on increasing the intrinsic ratio of leaf CO2/H2O exchange has limited opportunities for improvement. On the other hand, the derivation showed that daily vapor pressure deficit (VPD) weighted for the daily cycle of transpiration rate has a large, direct impact on TE. While VPD is often viewed as an environmental variable, daily weighted VPD can be under plant control as a result of partial stomatal closure during the midday. A critical feature of the partial stomatal closure is that transpiration rate is decreased resulting in conservation of soil water. The conserved soil water allows late-season, sustained physiological activity during subsequent periods of developing water deficits, which can be especially beneficial during reproductive development. The shift in the temporal dynamics of water use by water conservations traits has been shown in simulation studies to result in substantial yield increases. It is suggested from this analysis that effective water use through the growing season is more important for increasing crop yield than attempts focused on improving the static, intrinsic TE ratio.}, journal={FRONTIERS IN PLANT SCIENCE}, author={Sinclair, Thomas R.}, year={2018}, month={Sep} }
 @article{riar_cerezini_manandhar_sinclair_li_carter_2018, title={Expression of Drought-Tolerant N-2 Fixation in Heterogeneous Inbred Families derived from PI471938 and Hutcheson Soybean}, volume={58}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2017.02.0089}, abstractNote={ABSTRACT}, number={1}, journal={CROP SCIENCE}, author={Riar, Mandeep K. and Cerezini, Paula and Manandhar, Anju and Sinclair, Thomas R. and Li, Zenglu and Carter, Thomas E.}, year={2018}, pages={364–369} }
 @article{sinclair_shekoofa_isleib_balota_zhang_2018, title={Identification of Virginia-Type Peanut Genotypes for Water-Deficit Conditions Based on Early Decrease in Transpiration Rate with Soil Drying}, volume={58}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2018.05.0293}, abstractNote={Early decrease in transpiration rate as soil progressively dries allows soil water conservation for sustained crop physiological activity as water deficit continues to increase. This trait is likely to be particularly useful for peanut (Arachis hypogaea L.), which is often grown on sandy soil where water deficit can develop quickly. This study was undertaken to identify peanut genotypes that express this water conservation trait and to determine if it confers a yield advantage. Three approaches were taken. (i) Two populations of peanut were tested in controlled environments during progressive soil drying. Especially high thresholds of soil water content for initiation of decrease in transpiration rate were identified in three lines in each of the breeding populations. (ii) Nine genotypes were identified for field observation of leaf wilting under rain shelters and in the open field. There was a correspondence between the early decrease in transpiration rate with soil drying and delayed wilting. (iii) Yield trial data for three genotypes were examined to identify those lines that consistently had higher yields than the commercial check cultivar ‘Bailey’, particularly at low yield levels commonly associated with drier conditions. When expressing total seed yield in monetary return, these breeding lines had yield values that were consistently superior to Bailey below the US$2000 ha−1 threshold. Based on the three experimental approaches, N12006ol consistently expressed a desired response of early decrease in transpiration rate with soil drying, delayed wilting in the field when soil water deficit developed, and greater yield value than Bailey in low‐yield environments.}, number={6}, journal={CROP SCIENCE}, author={Sinclair, Thomas R. and Shekoofa, Avat and Isleib, Thomas G. and Balota, Maria and Zhang, Hao}, year={2018}, pages={2607–2612} }
 @article{sinclair_pradhan_shekoofa_2018, title={Inheritance of limited-transpiration trait in peanut: an update}, volume={32}, ISSN={["1542-7536"]}, DOI={10.1080/15427528.2017.1420000}, abstractNote={ABSTRACT Peanut (Arachis Hypogeae L.) is commonly grown on sandy soil and in environments with intermittent rainfall, both of which can lead to soil water-deficit. Limited transpiration (LT) under elevated vapor pressure deficit (VPD) can result in water conservation, allowing sustained physiological activity later in the season during reproductive development. The objective of this study was to expand the number of progeny lines phenotyped for expression of the LT trait from the mating of Tifrunner (LT trait not expressed) × NC 3033 (LT trait expressed) to allow a preliminary examination of inheritance. Half of the 24 phenotyped lines expressed LT with their VPD threshold ranging from 2.16 to 3.38 kPa. Six of the 12 genotypes expressing LT had a threshold at 2.65 kPa or less, which is the range likely to be relevant in most peanut environments. These results, indicating epistatic inheritance, are supportive of LT expression in progeny lines at a reasonable frequency for relevant use in cultivar development for water-deficit conditions.}, number={2}, journal={JOURNAL OF CROP IMPROVEMENT}, author={Sinclair, Thomas R. and Pradhan, Deepti and Shekoofa, Avat}, year={2018}, pages={281–286} }
 @article{pradhan_sinclair_alijani_2018, title={Nitrogen Fixation Establishment during Initial Growth of Grain Legume Species}, volume={32}, ISSN={["1542-7536"]}, DOI={10.1080/15427528.2017.1393648}, abstractNote={ABSTRACT Atmospheric nitrogen fixation as a result of the symbiosis between bacteria and legume species, can result in major advantages in providing host plants with organic nitrogen. The objective of the present study was to evaluate the physiological potential during early seedling development for initiation of nodulation and nitrogen fixation activity of four grain legumes species: soybean [Glycine max (L.)], cowpea [Vigna unguiculate (L.) Walp], common bean [Phaseolus vulgaris (L.)], and peanut [Arachis hypogaea (L.)]. Seedlings were grown on a hydroponic solution so that nodule development could be readily observed until about 3 weeks after germination. Nodules developed in all cases. Acetylene reduction activity (ARA) by soybean and cowpea was also found early in seedling development. In contrast, peanut and common bean showed little or no development of ARA during seedling development. The results provided insight into differences in physiological potential among grain legumes in establishing symbiotic nitrogen fixation during crop establishment. These results indicate those species/cultivars that are candidates for readily establishing nitrogen fixation activity during the seedling stage of plant development.}, number={1}, journal={JOURNAL OF CROP IMPROVEMENT}, author={Pradhan, Deepti and Sinclair, Thomas R. and Alijani, Khadijeh}, year={2018}, pages={50–58} }
 @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} }
 @misc{sinclair_nogueira_2018, title={Selection of host-plant genotype: the next step to increase grain legume N-2 fixation activity}, volume={69}, ISSN={["1460-2431"]}, DOI={10.1093/jxb/ery115}, abstractNote={Symbiotic N2 fixation research thus far has been primarily focused on selection of bacteria. However, little progress in impacting crop yields has resulted from this approach. Bacteria introduced in field soils rarely compete well with indigenous bacteria, including mutated lines selected for high nitrogen fixation capacity. Consequently, introduction of 'elite' bacteria in fields commonly does not result in crop yield increase. This review highlights that the primary regulation of N2 fixation is a result of response of integrated physiological activity at the plant level. Nitrogen feedback from the host plant plays an important role in regulating the N2 fixation rate. Rapid sequestration of fixed nitrogen by the plant is especially important for high N2 fixation activity. In addition, water cycling in the plant between the shoot and nodules plays a key role in sustaining high N2 fixation activity. Therefore, attention in selecting the host-plant genotype is suggested to be the next step to increasing N2 fixation activity of grain legumes.}, number={15}, journal={JOURNAL OF EXPERIMENTAL BOTANY}, author={Sinclair, Thomas R. and Nogueira, Marco A.}, year={2018}, month={Jul}, pages={3523–3530} }
 @article{shaaban_wahbi_sinclair_2018, title={Sowing date and mulch to improve water use and yield of wheat and barley in the Middle East environment}, volume={165}, ISSN={["1873-2267"]}, DOI={10.1016/j.agsy.2018.05.011}, abstractNote={Water is a critical limitation of crop yield in Middle East environments. Cereal production is limited to the winter months when rains occur. Options to increase the effective use of the available water to increase yield could be of direct benefit. This simulation study was undertaken for four locations in Syria that encompassed the wetter climate for wheat production in the north and the drier climate for barley production in the middle and south. Simulations were done for four sowing dates along with either the absence or presence of mulch on the soil surface. These simulations showed that sowing in early November for both barley and wheat resulted in the highest average yields among the simulated sowing dates. Surprisingly, the retention of straw mulch on the soil surface had only a small impact on yield. In most cases, yield increases were fairly modest in the range of about 4 to 9%. Since management practices to retain straw mulch in place in the field are challenging in the Syrian environment, these simulations do not indicate priority be given to developing this management practice solely for water retention.}, journal={AGRICULTURAL SYSTEMS}, author={Shaaban, Ahmad Shams Aldien and Wahbi, Ammar and Sinclair, Thomas R.}, year={2018}, month={Sep}, pages={26–32} }
 @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{roberts_braun_sinclair_lobell_schlenker_2017, title={Comparing and combining process-based crop models and statistical models with some implications for climate change}, volume={12}, ISSN={["1748-9326"]}, DOI={10.1088/1748-9326/aa7f33}, abstractNote={We compare predictions of a simple process-based crop model (Soltani and Sinclair ), a simple statistical model (Schlenker and Roberts ), and a combination of both models to actual maize yields on a large, representative sample of farmer-managed fields in the Corn Belt region of the United States. After statistical post-model calibration, the process model (Simple Simulation Model, or SSM) predicts actual outcomes slightly better than the statistical model, but the combined model performs significantly better than either model. The SSM, statistical model and combined model all show similar relationships with precipitation, while the SSM better accounts for temporal patterns of precipitation, vapor pressure deficit and solar radiation. The statistical and combined models show a more negative impact associated with extreme heat for which the process model does not account. Due to the extreme heat effect, predicted impacts under uniform climate change scenarios are considerably more severe for the statistical and combined models than for the process-based model.}, number={9}, journal={ENVIRONMENTAL RESEARCH LETTERS}, author={Roberts, Michael J. and Braun, Noah O. and Sinclair, Thomas R. and Lobell, David B. and Schlenker, Wolfram}, year={2017}, month={Sep} }
 @article{sinclair_2017, title={Early Partial Stomata Closure with Soil Drying}, ISBN={["978-3-319-56320-6"]}, ISSN={["2191-5555"]}, DOI={10.1007/978-3-319-56321-3_2}, abstractNote={The soil volumetric water content at which partial stomatal closure is initiated with soil drying is a critical variable in comparing the sensitivity of plants to water-deficit conditions. Those plants that initiate stomatal closure at higher soil water contents result in soil water conservation, which allows water use to be spread over more days resulting in sustained crop physiological activity during the ongoing development of water deficit. The threshold for the initiation of the partial stomatal closure appears to be fairly stable for individual genotypes when referenced against soil water contents, defined as fraction transpirable soil water (FTSW). Although early partial closure of stomata is associated with decreased photosynthetic capacity, simulations have shown that the overall benefit of sustained physiological activity with developing drought as a result of this trait is generally expected to allow yield increase.}, journal={WATER-CONSERVATION TRAITS TO INCREASE CROP YIELDS IN WATER-DEFICIT ENVIRONMENTS: CASE STUDIES}, author={Sinclair, Thomas R.}, year={2017}, pages={5–9} }
 @article{shekoofa_sinclair_aninbon_holbrook_isleib_ozias-akins_chu_2017, title={Expression of the limited-transpiration trait under high vapour pressure deficit in peanut populations: Runner and virginia types}, volume={203}, ISSN={["1439-037X"]}, DOI={10.1111/jac.12204}, abstractNote={Abstract}, number={4}, journal={JOURNAL OF AGRONOMY AND CROP SCIENCE}, author={Shekoofa, A. and Sinclair, T. R. and Aninbon, C. and Holbrook, C. C. and Isleib, T. G. and Ozias-Akins, P. and Chu, Y.}, year={2017}, month={Aug}, pages={295–300} }
 @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} }
 @article{sinclair_2017, title={Limited-Transpiration Rate Under Elevated Atmospheric Vapor Pressure Deficit}, ISBN={["978-3-319-56320-6"]}, ISSN={["2191-5555"]}, DOI={10.1007/978-3-319-56321-3_3}, abstractNote={The driving force of transpiration rate is the gradient in vapor pressure between the dry atmosphere and the wet interior of leaves, commonly referred to as the vapor pressure deficit (VPD). The other key variable is the resistance to vapor diffusion from the leaves attributed to the aperture of the stomata pores. Partial stomatal closure at modest VPD results in limited-transpiration rate and, hence, conservative use of water. The conservative use of water allows more water to be available to sustain physiological activity later in the growing species. However, in many crop species, the limited-transpiration rate is not commonly expressed in commercial genotypes. Only recently have specific genotypes been identified that express the trait, and these genotypes are now being exploited in breeding programs. These breeding efforts have led to commercial cultivars in maize and soybean resulting in increased yields under dry land conditions.}, journal={WATER-CONSERVATION TRAITS TO INCREASE CROP YIELDS IN WATER-DEFICIT ENVIRONMENTS: CASE STUDIES}, author={Sinclair, Thomas R.}, year={2017}, pages={11–16} }
 @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{guiguitant_marrou_vadez_gupta_kumar_soltani_sinclair_edmond ghanem_2017, title={Relevance of limited-transpiration trait for lentil (Lens culinaris Medik.) in South Asia}, volume={209}, ISSN={["1872-6852"]}, DOI={10.1016/j.fcr.2017.04.013}, abstractNote={Drought is one of the most important environmental factors that limit crop production. It has been hypothesized that a limited-transpiration trait under high vapor pressure deficit (VPD) is a mechanism for water conservation leading to yield increase under water-deficit conditions. The first research objective was to compare expression of limited-transpiration (TRlim) in lentil (Lens culinaris Medik.) observed by whole-plant measurements in controlled environments and under natural conditions outdoors during a high VPD period. Seventeen lentil genotypes were studied. All genotypes showed a linear increase with increasing VPD under natural conditions. Differences were observed among genotypes in their expression of TRlim with increasing VPD in the controlled environment. Almost all genotypes showed a VPD breakpoint at approximately 3.4 kPa. A simulation analysis was conducted across South Asia to identify where, how often, and how much this trait in lentil would benefit farmers with four different VPD breakpoint scenarios (VPD breakpoint at 3.4, 2.2, 1.1 kPa, and VPD-insensitive). Results showed that the limited-transpiration trait at a low simulated threshold (1.1 kPa) can result in improved lentil performance in drought-prone environments and that the impact of the trait on lentil productivity varies with geography and environment. The largest average yield increase was simulated for drought-prone environments (250 g m−2). Outcomes from this simulation study provide insights into the plausible role of the limited-transpiration trait under high VPD in future lentil genetic improvement and implies that a search for germplasm with a breakpoint as low as 1.1 kPa needs to be made.}, journal={FIELD CROPS RESEARCH}, author={Guiguitant, Julie and Marrou, Helene and Vadez, Vincent and Gupta, Priyanka and Kumar, Shiv and Soltani, Afshin and Sinclair, Thomas R. and Edmond Ghanem, Michel}, year={2017}, month={Aug}, pages={96–107} }
 @article{sinclair_2017, title={Soybean}, ISBN={["978-3-319-56320-6"]}, ISSN={["2191-5555"]}, DOI={10.1007/978-3-319-56321-3_4}, abstractNote={Soybean (Glycine max (Merr.) L) is not often irrigated (<5% of the land area in the major producing countries), so the crop is vulnerable to variations in rainfall. Even short periods of soil water deficit can adversely affect soybean yields, especially because of the high sensitivity of its symbiotic nitrogen fixation to even minor decreases in soil moisture. Therefore, soil water conservation traits have the potential to result in yield increases. Curiously, little variation has been identified among soybean genotypes for early partial stomatal closure with soil drying. On the other hand, a few genotypes have been identified that express initiation of partial stomatal closure at vapor-pressure deficit as low as 2 kPa. Genotype PI 416937, in particular, has become an important genetic contributor in developing soybean cultivars for dry-land conditions. This genotype has been found to have unique properties in plant hydraulic conductivity and aquaporin expression.}, journal={WATER-CONSERVATION TRAITS TO INCREASE CROP YIELDS IN WATER-DEFICIT ENVIRONMENTS: CASE STUDIES}, author={Sinclair, Thomas R.}, year={2017}, pages={17–26} }
 @article{schoppach_fleury_sinclair_sadok_2017, title={Transpiration Sensitivity to Evaporative Demand Across 120 Years of Breeding of Australian Wheat Cultivars}, volume={203}, ISSN={["1439-037X"]}, DOI={10.1111/jac.12193}, abstractNote={Abstract}, number={3}, journal={JOURNAL OF AGRONOMY AND CROP SCIENCE}, author={Schoppach, R. and Fleury, D. and Sinclair, T. R. and Sadok, W.}, year={2017}, month={Jun}, pages={219–226} }
 @book{water-conservation traits to increase crop yields in water-deficit environments: case studies_2017, ISBN={["978-3-319-56320-6"]}, ISSN={["2191-5555"]}, DOI={10.1007/978-3-319-56321-3}, abstractNote={This volume explores specific approaches that have shown to result in crop yield increases. Research on the physiological understanding of these methods has led to the development of practical applica}, journal={WATER-CONSERVATION TRAITS TO INCREASE CROP YIELDS IN WATER-DEFICIT ENVIRONMENTS: CASE STUDIES}, year={2017}, pages={1–95} }
 @article{schoppach_soltani_sinclair_sadok_2017, title={Yield comparison of simulated rainfed wheat and barley across Middle-East}, volume={153}, ISSN={["1873-2267"]}, DOI={10.1016/j.agsy.2016.12.017}, abstractNote={Rain-fed wheat and barley are key crops in the Middle-East. A slight improvement in the effective use of water and in grain yield could greatly improve lives of subsistence farmers. This study aimed to evaluate the relative merits of wheat and barley in this region by simulating yields across 404 uniformly spread locations across 30 growing seasons. The results emphasized the primary importance of sowing date in each location. In comparison to wheat, barley generally was capable of rapid progress through its development stages allowing it to avoid deleterious late-season droughts and to have greater yields in low rainfall regions. A large part of Middle-East appeared unsuited for rain-fed production of these two grain species if seasonal yield variability is a concern.}, journal={AGRICULTURAL SYSTEMS}, author={Schoppach, Remy and Soltani, Afshin and Sinclair, Thomas R. and Sadok, Walid}, year={2017}, month={May}, pages={101–108} }
 @article{halilou_hissene_michelangeli_hamidou_sinclair_soltani_mahamane_vadez_2016, title={Determination of coefficient defining leaf area development in different genotypes, plant types and planting densities in peanut (Arachis hypogeae L.)}, volume={199}, ISSN={["1872-6852"]}, DOI={10.1016/j.fcr.2016.09.013}, abstractNote={Rapid leaf area development may be attractive under a number of cropping conditions to enhance the vigor of crop establishment and allow rapid canopy closure for maximizing light interception and shading of weed competitors. This study was undertaken to determine (1) if parameters describing leaf area development varied among ten peanut (Arachis hypogeae L.) genotypes grown in field and pot experiments, (2) if these parameters were affected by the planting density, and (3) if these parameters varied between Spanish and Virginia genotypes. Leaf area development was described by two steps: prediction of main stem number of nodes based on phyllochron development and plant leaf area dependent based on main stem node number. There was no genetic variation in the phyllochron measured in the field. However, the phyllochron was much longer for plants grown in pots as compared to the field-grown plants. These results indicated a negative aspect of growing peanut plants in the pots used in this experiment. In contrast to phyllochron, there was no difference in the relationship between plant leaf area and main stem node number between the pot and field experiments. However, there was genetic variation in both the pot and field experiments in the exponential coefficient (PLAPOW) of the power function used to describe leaf area development from node number. This genetic variation was confirmed in another experiment with a larger number of genotypes, although possible G × E interaction for the PLAPOW was found. Sowing density did not affect the power function relating leaf area to main stem node number. There was also no difference in the power function coefficient between Spanish and Virginia genotypes. SSM (Simple Simulation model) reliably predicted leaf canopy development in groundnut. Indeed the leaf area showed a close agreement between predicted and observed values up to 60000 cm2 m-2. The slightly higher prediction in India and slightly lower prediction in Niger reflected GxE interactions. Until more understanding is obtained on the possible GxE interaction effects on the canopy development, a generic PLAPOW value of 2.71, no correction for sowing density, and a phyllochron on 53 °C could be used to model canopy development in peanut.}, journal={FIELD CROPS RESEARCH}, author={Halilou, Oumarou and Hissene, Halime Mahamat and Michelangeli, Jose A. Clavijo and Hamidou, Falalou and Sinclair, Thomas R. and Soltani, Afshin and Mahamane, Saadou and Vadez, Vincent}, year={2016}, month={Dec}, pages={42–51} }
 @article{devi_sinclair_jain_gallo_2016, title={Leaf aquaporin transcript abundance in peanut genotypes diverging in expression of the limited-transpiration trait when subjected to differing vapor pressure deficits and aquaporin inhibitors}, volume={156}, ISSN={["1399-3054"]}, DOI={10.1111/ppl.12378}, abstractNote={A plant trait currently being exploited to decrease crop yield loss under water‐deficit conditions is limited‐transpiration rate (TRlim) under high atmospheric vapor pressure deficit (VPD) conditions. Although limited genotype comparisons for the TRlim trait have been performed in peanut (Arachis hypogaea), no detailed study to describe the basis for this trait in peanut has been reported. Since it has been hypothesized that the TRlim trait may be a result of low leaf hydraulic conductance associated with aquaporins (AQPs), the first objective of this study was to examine a possible correlation of TRlim to leaf AQP transcriptional profiles in six peanut cultivars. Five of the studied cultivars were selected because they expressed TRlim while the cultivar York did not. Transcripts of six AQPs were measured. Under exposure to high vapor pressure deficit, cultivar C 76‐16 had decreased AQP transcript abundance for four of the six AQPs but in York only one AQP had decreased abundance. The second objective was to explore the influence of AQP inhibitors mercury and silver on expression of TRlim and AQP transcription profiles. Quantitative RT‐PCR data were compared in cultivars York and C 76‐16, which had the extreme response in TR to VPD. Inhibitor treatment resulted in increased abundance of AQP transcripts in both. The results of these experiments indicate that AQP transcript abundance itself may not be useful in identifying genotypes expressing the TRlim trait under high VPD conditions.}, number={4}, journal={PHYSIOLOGIA PLANTARUM}, author={Devi, M. Jyostna and Sinclair, Thomas R. and Jain, Mukesh and Gallo, Maria}, year={2016}, month={Apr}, pages={387–396} }
 @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{hissene_vadez_michelangeli_halilou_ndoye_soltani_sinclair_2016, title={Quantifying Leaf Area Development Parameters for Cowpea [Vigna unguiculata (L.) Walpers]}, volume={56}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2016.02.0132}, abstractNote={Cowpea [Vigna unguiculata (L.) Walpers] is a major crop legume for the Sahelian zone in Africa. An accurate simulation of the growth and yield for cowpea that considers the environment would be a robust tool for evaluating improved management and plant genetics. The objective of this study was to parameterize a simple model framework to describe cowpea leaf area development. To obtain field data in divergent environments, leaf area development was measured for four genotypes at two sites: Patancheru, India, and Bambey, Senegal. In addition, the effect of plant density was tested at Patancheru. Leaf area development was considered in two steps: the increase in main stem node number as a function of temperature (i.e., phyllochron) and plant leaf area as a function of main stem node number. The difference in phyllochron values among genotypes was not significant at Bambey, but one genotype at Patancheru significantly diverged from the others. Also, there was a plant density effect at Patancheru, especially for genotype Suvita‐2. An allometric power function, used to calculate plant leaf area based on the number of nodes, required two parameters: PLAPOW, the exponent in the function, and PLACON, the linear multiplier of the equation. Determination of the two parameters at Patancheru showed a genotype effect in both site and plant‐density effect. To examine the practical impact of genotypic differences and density effects in light interception and shading, estimated leaf development parameters were used to calculate light interception. There was very little variation in light interception resulting from the observed range in leaf phyllochron, PLAPOW, and PLACON and in density responses among the cowpea genotypes. The results of these experiments showed that, in most cases, a single set of parameters can be used to describe light interception by cowpea leaf canopies.}, number={6}, journal={CROP SCIENCE}, author={Hissene, Halime Mahamat and Vadez, Vincent and Michelangeli, Jose Clavijo and Halilou, Oumarou and Ndoye, Ibrahima and Soltani, Afshin and Sinclair, Thomas}, year={2016}, pages={3209–3217} }
 @article{devi_sinclair_taliercio_2016, title={Silver and zinc inhibitors influence transpiration rate and aquaporin transcript abundance in intact soybean plants}, volume={122}, ISSN={["1873-7307"]}, DOI={10.1016/j.envexpbot.2015.10.006}, abstractNote={Soybean genotype PI 416937 has previously been found to have low leaf hydraulic conductivity, which was hypothesized to be the basis for limited transpiration (TRlim) rates under high vapor pressure deficit. Previous studies with de-rooted shoots showed there was a consistency in the expression of TRlim and plant response to exposure to silver, an aquaporin (AQP) inhibitor. However, it is not clear what confounding influence treatments with metal AQP inhibitors may have on AQP transcript expression. This study was undertaken to extend the observations of response to silver and zinc using intact plants. In a comparison of four genotypes, intact plants of PI 416937 were uniquely insensitive to exposure to silver and of PI 471938 were uniquely insensitive to zinc. RNA abundance of eight AQPs was measured after treatment with the AQP inhibitors. There were differences in the abundance of RNA among genotypes. There was a general trend of less change in abundance in PI 416937 following silver treatment in contrast to increased abundance in the other genotypes. This result would be consistent with little or no response in transpiration rate in the intact plants of PI 416937 following silver treatment. Following zinc treatment, there was a rapid increase in RNA abundance in PI 471938 in comparison to the other genotypes. However, the changes in AQP abundance following treatment with metal inhibitors indicates the likely interaction of direct response of AQP to metals and alternation of expression of AQP transcripts. These results indicate that the results from treatment with metal inhibitors should likely be considered only as preliminary screens from which genotypes need to be tested directly for the TRlim trait.}, journal={ENVIRONMENTAL AND EXPERIMENTAL BOTANY}, author={Devi, M. Jyostna and Sinclair, Thomas R. and Taliercio, Earl}, year={2016}, month={Feb}, pages={168–175} }
 @article{ricaurte_michelangeli_sinclair_rao_beebe_2016, title={Sowing Density Effect on Common Bean Leaf Area Development}, volume={56}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2016.01.0056}, abstractNote={Sowing density is a major management factor that affects growth and development of grain crops by modifying the canopy light environment and interplant competition for water and nutrients. While the effects of density and plant architecture on static vegetative and reproductive growth traits have been explored previously in common bean (Phaseolus vulgaris L.), there are no reports of intensive measurements of the temporal dynamics on node addition and leaf area development. Such results are reported here from two sites of field experiments where the effects of sowing densities (5, 10, 15, 20, 25, and 35 plants m−2) and genotypes with contrasting plant architectures (two each from growth habits I, II, and III) were assessed. Analysis of the phyllochron (°C node−1) indicated genotype and density effects (but no interaction) on the rate of node addition. While significant, these differences amounted to <2 d of leaf development at either site. In terms of leaf area development, analysis using a power function reflected large differences in the dynamics and final size of individual plant leaf area (PLA) between the lower density (<15 plants m−2) treatments and commonly used values (>20 plants m−2) at the growth habit but not genotype level. These differences in node addition and leaf development dynamics translated to marked differences among growth habits and densities in estimated leaf area indices and, consequently, in the estimated fraction of intercepted light at lower densities.}, number={5}, journal={CROP SCIENCE}, author={Ricaurte, Jaumer and Michelangeli, Jose A. Clavijo and Sinclair, Thomas R. and Rao, Idupulapati M. and Beebe, Stephen E.}, year={2016}, pages={2713–2721} }
 @article{michelangeli_sinclair_bliznyuk_2016, title={Using an Arrhenius-type function to describe temperature response of plant developmental processes: inference and cautions}, volume={210}, ISSN={["1469-8137"]}, DOI={10.1111/nph.13812}, abstractNote={Managing the impacts of weather on agricultural systems requires developing practices and novel germplasm capable of withstanding erratic temperature regimes, which will be critical under projected global climate change scenarios (Lobell et al., 2008). Thus, describing temperature responses of developmental and growth processes, and identifying the underlying genetic signal has long been a key challenge in plant biology. In this letter, we review the approach used to describe temperature responses presented by Parent & Tardieu (2012) using a modified nonlinear function originally developed to study enzyme kinetics. Three specific issues are addressed in this letter. (1) Does the function offer mechanistic insight? (2) Are there clear statistical criteria for function evaluation? (3) Does the function appropriately relate to observed genetic variation in temperature response? Using Eqn 2, Parent & Tardieu (2012) specifically tested two hypotheses: (1) genotypes of the species originating from ‘cold or warm’ areas (e.g. maize lines from temperate or tropical regions) have different temperature responses, via the analysis of fitted parameters of a nonlinear function (derivation discussed later); and (2) one or more of the solved parameters of the function used were similar within or across species. The test of shape of the response curves were studied using normalized rates (referenced to 20°C) of growth (tissue expansion and cell division) and development (germination, node addition, time to anthesis) from novel and previously published experiments using several genotypes of wheat (Triticum aestivum), maize (Zea mays), rice (Oryza spp.) and barley (Hordeum vulgare) and an additional 14 species via a meta-analysis. An initial concern is the interpretation of the parameters resulting from fitting Eqn 2 to experimental data. For instance, according to Parent & Tardieu (2012) the parameter α is actually the /ratio in Eqn 1. Hence, when fitting α separately in Eqn 2, the original dependency of the ratio on is lost, affecting the estimation process and the claimed inferences. Consequently, regression fits of Eqn 2 essentially become empirical descriptions of the experimental data. While the use of empirical functions to study the genetic control of different growth and developmental processes is well established, it seems unjustified to suggest that the empirical structure of Eqn 2 provides insight about an ‘immutable law with parameters based on physical constraints’ in plant temperature response. Therefore, we conclude that Eqn 2 is essentially another possibility for describing plant responses to temperature without being able to claim any particular insight about the basic nature of the processes influencing temperature sensitivity. As suggested by Price et al. (2012), a model must first be logically consistent, and second, provide biologically useful or meaningful insight. As discussed earlier, use of Boltzmann–Arrhenius functions derived for individual enzymatic reactions can only be considered approximations of temperature sensitivity of whole-organism metabolic rates, and may well miss representing key processes involved in temperature response (Price et al., 2012). This problem seems especially challenging in a plant breeding context, where identifying and using specific phenotypic targets in selection schemes would be critical in improving a complex trait such as developmental rate or organ temperature responses. Ambiguity about the derived parameters for Eqn 2 seems to preclude the possibility of gaining insights about genetic variability. This ambiguity is highlighted by the fact that Parent & Tardieu (2012) offered eight alternative approaches (Table 1) to solve the three parameters in Eqn 2. These approaches considered all possible combinations in determining the parameters of Eqn 2 (, T0 and α) by either solving all parameters (referred to as being ‘free’) or by fixing up to two parameters (i.e. ‘fixed’) and solving the rest in the regression analysis. Table 1 gives the identifications of the three approaches in comparison with genotype or species, or between and across species, depending on the data set. Critically, details of the data pooling procedures from the different temperature experiments were not readily available in Parent & Tardieu (2012), making assessments of the fitting procedures difficult since the datasets used varied widely in scope, experimental conditions, measured traits and sample sizes. Furthermore, the eight approaches in evaluating Eqn 2 were not all fitted by using the same optimization procedures, and relied on assumptions that may well not have been met. More formally, numerical issues aside, the objective functions presented in their Supporting Information Fig. S3 (p. 5) for the three models are equivalent to Gaussian maximum likelihood objective functions (with independent errors) only under the strong assumption of equal variances across all lines and temperature treatments. This assumption was not stated, let alone justified, in the manuscript. This can be problematic, since failure to account for variance heterogeneity or observation independence can lead to inaccurate parameter estimates and/or distorted standard errors (Ritz & Streibig, 2008), and affect criteria for model selection (Burnham & Anderson, 2002). Packages or routines exist in all major statistical software to accurately model these scenarios (e.g. gnls package in R, proc nlin in SAS®). The analysis of the model selection approach used by Parent & Tardieu (2012) also raises concerns, particularly in terms of the model selected as best, and those that are discarded. In each analysis scenario, the fitted models were ranked based on the Bayesian Information Criterion (BIC), while Akaike's Information Criterion (AIC) was also provided. Both measures are based on minimizing the Kullback–Leibler divergence (i.e. the amount of information lost when using a model to approximate reality), but the derivations and interpretations of the two statistics differ (Burnham & Anderson, 2002). For both cases, models are penalized depending on the number of parameters, and the best model within the subset is that with the smallest criterion value. Since several models may have similar information criteria values, an established selection approach is based on the differences in information criteria values between the best (i.e. lowest AIC or BIC value) model, and the rest (denoted as ΔAIC or ΔBIC). For this purpose, Burnham & Anderson (2002) proposed a widely-used rule of thumb where models approximately 2 AIC or BIC units from the best model have substantial empirical support, those within 4–7 units considerably less, while models > 10 units away have essentially no support. Furthermore, the ΔAIC or ΔBIC values are also used to compute weights (denoted as wAIC or wBIC), which are interpreted as the relative likelihood that each model (normalized to sum to one) is the expected best model among those tested (Burnham & Anderson, 2002). However, the statistical model and approach used to calculate the likelihoods and information criteria in Parent & Tardieu (2012) was not stated explicitly. With these guidelines and comments in mind, results in Supporting Information Table S1 of Parent & Tardieu (2012) indicated that models with parameters estimated by genotype cannot be discarded for maize, rice and wheat. Specifically, for maize and rice, none of the model fits are farther apart than 3.2 BIC units from each other, suggesting none of them should be discarded outright for making inferences about genotypic differences. In addition, the best models for both maize and rice are not those where parameters are estimated across all genotypes (model M.0), but instead M.1a (with wBIC of 0.27 and 0.21, respectively), which has T0 estimated by genotype, and the remaining parameter across genotypes. Although for wheat the best model is in fact M.0, it is < 0.5 BIC units from model M.1a, and consequently, the latter should also be considered a strong candidate model. Supposing that the model interpretations and fitting procedures raised were addressed, the model selection procedures used should lead to more cautious conclusions than those presented in Parent & Tardieu (2012). The results seem to indicate that, in all likelihood, the temperature response of developmental processes is not the same for all genotypes within each crop species in individual crop experiment datasets (i.e. the fits of genotypes of maize, rice and wheat). Thus, the overall conclusion that breeding has not changed the temperature responses within these crops cannot be supported given the data utilized. For the comparison of maize, rice, wheat and A. thaliana (their Table S1, bottom), a more appropriate interpretation would indicate that model M.2b is the most likely model within those tested, while models M.1a, M.2c, M.2a and M.3 cannot be discarded. In this case, while the original overall conclusions of Parent & Tardieu (2012) would stand, the identification of the parameters under genetic control and the uncertainty around their estimates are more tenuous than those provided. Moreover, many peer-reviewed publications have identified genetic variability for the temperature responses of various processes within the ranges studied in Parent & Tardieu (2012) in maize (e.g. Pešev, 1970; Eagles & Hardacre, 1979; Maryam & Jones, 1983; Dolstra et al., 1994), wheat (Cao & Moss, 1989; Slafer & Rawson, 1995; Robertson et al., 1996) and rice (Glaszmann et al., 1990; Yin & Kropff, 1996; Yin et al., 1996; Fujino et al., 2004; Jiang et al., 2008; Suh et al., 2010; Lin et al., 2014), including studies in molecular biology, whole-plant physiology and modeling. Taken as a whole, the large body of evidence suggesting genetic control of temperature responses should at least be considered when making conclusions regarding the effects of evolution or selection on current crop responses. The authors thank Martijn Slot for helpful comments that improved the final version of the paper.}, number={2}, journal={NEW PHYTOLOGIST}, author={Michelangeli, Jose A. Clavijo and Sinclair, Thomas R. and Bliznyuk, Nikolay}, year={2016}, month={Apr}, pages={377–379} }
 @article{shekoofa_sinclair_messina_cooper_2016, title={Variation Among Maize Hybrids in Response to High Vapor Pressure Deficit at High Temperatures}, volume={56}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2015.02.0134}, abstractNote={ABSTRACT}, number={1}, journal={CROP SCIENCE}, author={Shekoofa, Avat and Sinclair, Thomas R. and Messina, Carlos D. and Cooper, Mark}, year={2016}, pages={392–396} }
 @article{soltani_sinclair_2015, title={A comparison of four wheat models with respect to robustness and transparency: Simulation in a temperate, sub-humid environment}, volume={175}, ISSN={["1872-6852"]}, DOI={10.1016/j.fcr.2014.10.019}, abstractNote={There is debate over determining the appropriate model complexity to simulate crop development, growth, and yield. An approach that is sometimes suggested is to compare the performance of models using common datasets for ability to reproduce specific sets of observations. However, this narrow-focused approach overlooks the critical heuristic aspects in using models to explore and understand the behavior of cropping systems at the process level. We argue that the key criteria of model evaluation are both transparency and overall robustness. While model robustness (often mislabeled as “validation”) is sometimes presented at some level, model transparency has normally been ignored in model comparison studies. The objective of this paper is to examine the transparency and robustness of four wheat (Triticum aestivum L.) models that are markedly different in detail: CropSyst and SSM as simpler models and APSIM and DSSAT as more complex models. Data for development, growth and yield of the crop were collected from a wide range of environmental and growth conditions in the Grogan region of Iran. Models parameterization was done according to the guidelines for each model and then model testing and comparison were performed using different datasets. The two simpler models were found to be more robust than the complex models; across all the evaluated crop variables, the coefficient of variation in yield prediction was lower for SSM (8.2%) and CropSyst (14.3%) than APSIM (15.0%) and DSSAT (18.5%). Transparency of the models was mainly gauged by the number of input parameters needed by the models. Simulations using APSIM (292 parameters) and DSSAT (211 parameters) required the definition of about fourfold more parameters than CropSyst (50 parameters) and SSM (55 parameters). The simulation results showed no significant relationship between model performance and parameter number; the lack of transparency sacrificed in complexity was not rewarded by increased robustness in the output.}, journal={FIELD CROPS RESEARCH}, author={Soltani, Afshin and Sinclair, Thomas R.}, year={2015}, month={Apr}, pages={37–46} }
 @article{devi_sinclair_taliercio_2015, title={Comparisons of the Effects of Elevated Vapor Pressure Deficit on Gene Expression in Leaves among Two Fast-Wilting and a Slow-Wilting Soybean}, volume={10}, ISSN={["1932-6203"]}, DOI={10.1371/journal.pone.0139134}, abstractNote={Limiting the transpiration rate (TR) of a plant under high vapor pressure deficit (VPD) has the potential to improve crop yield under drought conditions. The effects of elevated VPD on the expression of genes in the leaves of three soybean accessions, Plant Introduction (PI) 416937, PI 471938 and Hutcheson (PI 518664) were investigated because these accessions have contrasting responses to VPD changes. Hutcheson, a fast-wilting soybean, and PI 471938, a slow-wilting soybean, respond to increased VPD with a linear increase in TR. TR of the slow-wilting PI 416937 is limited when VPD increases to greater than about 2 kPa. The objective of this study was to identify the response of the transcriptome of these accessions to elevated VPD under well-watered conditions and identify responses that are unique to the slow-wilting accessions. Gene expression analysis in leaves of genotypes PI 471938 and Hutcheson showed that 22 and 1 genes, respectively, were differentially expressed under high VPD. In contrast, there were 944 genes differentially expressed in PI 416937 with the same increase in VPD. The increased alteration of the transcriptome of PI 416937 in response to elevated VPD clearly distinguished it from the other slow-wilting PI 471938 and the fast-wilting Hutcheson. The inventory and analysis of differentially expressed genes in PI 416937 in response to VPD is a foundation for further investigation to extend the current understanding of plant hydraulic conductivity in drought environments.}, number={10}, journal={PLOS ONE}, author={Devi, Mura Jyostna and Sinclair, Thomas R. and Taliercio, Earl}, year={2015}, month={Oct} }
 @article{wherley_dukes_cathey_miller_sinclair_2015, title={Consumptive water use and crop coefficients for warm-season turfgrass species in the Southeastern United States}, volume={156}, ISSN={["1873-2283"]}, DOI={10.1016/j.agwat.2015.03.020}, abstractNote={Increased urban demand for landscape irrigation, as well as interest in promoting water-use efficient species by municipalities, water purveyors, and homeowners associations emphasize the need for comparative data on consumptive water use by warm-season lawn grasses. The objective of this study was to quantify actual evapotranspiration (ETa) and to develop crop coefficients (Kc) for four warm-season turfgrass species, namely ‘Tifway’ bermudagrass (Cynodon dactylon (L.) Pers. x Cynodon transvaalensis Burtt-Davy), ‘Empire’ zoysiagrass (Zoysia japonica Steud.), ‘Floratam’ St. Augustinegrass [Stenotaphrum secundatum (Walter) Kuntze], and ‘Argentine’ bahiagrass (Paspalum notatum Flugge). Crop coefficients were derived by dividing ETa (measured directly from lysimeter weight change over 24 to 72-h periods) by reference evapotranspiration (ETo) calculated from the ASCE–EWRI Standardized Method using onsite weather station data. Data were collected over three seasons from non-stressed, well-watered turf. For 17 of the 30 measurement periods, Kc did not differ among the 4 species, and on 24 of 30 periods zoysiagrass, bermudagrass, and St. Augustinegrass Kc did not differ from one another. A trend toward elevated Kc was observed in bahiagrass in years 2 and 3, particularly during early spring measurement periods. Kc values for all species fluctuated across seasons and years, peaking to ∼0.8 during active growth periods when vapor pressure deficit and solar radiation were greatest, and declining to ∼0.3 in late fall and winter. Root growth differences among the species appeared to have a stronger relationship to ET rates than did shoot growth rate. Results demonstrated that the commonly recommended warm-season turf coefficient of 0.6, while approximating overall average annual ETa, under-predicted ETa during active growth periods and over-predicted ETa during late fall and winter periods, when turf was slowly growing or quiescent. The results indicate seasonal refinement of Kc values may be needed to more effectively meet consumptive water use requirements of warm-season turfgrasses.}, journal={AGRICULTURAL WATER MANAGEMENT}, author={Wherley, B. and Dukes, M. D. and Cathey, S. and Miller, G. and Sinclair, T.}, year={2015}, month={Jul}, pages={10–18} }
 @article{choudhary_sinclair_messina_cai_warner_cooper_2015, title={Inhibitor screen for limited-transpiration trait among maize hybrids}, volume={109}, ISSN={["1873-7307"]}, DOI={10.1016/j.envexpbot.2014.07.015}, abstractNote={A plant trait to minimize the impact of drought on crop yield is limited-transpiration rate (TR) under high ambient vapor pressure deficit (VPD) so that soil water is conserved to sustain grain fill. Variation among maize (Zea mays L.) hybrids has been identified for the existence of the limited-TR trait at high atmospheric VPD, and the VPD at which TR becomes limited. Further, it has been shown that the TR limitation at high VPD is related to plant hydraulic conductance, which may be due to differences in aquaporin expression. This paper reports studies to relate the TR response of 21 maize hybrids to treatment of leaves and intact plants with cycloheximide (CHX) and four aquaporin inhibitors: silver (AgNO3), gold (HAuCl4), zinc (ZnCl2), and mercury (HgCl2). There was no discrimination among hybrids based on treatment with Hg or CHX. Segregation between hybrids for response to increasing VPD corresponded with differences in leaf response to Ag and Au treatment and intact plant response to Zn. The highest correlation (r = 0.90) between VPD breakpoint and TR response to inhibitor was with Ag treatment of leaves. These results indicate that Ag may be an effective initial screen for expression of the limited-TR trait under high VPD.}, journal={ENVIRONMENTAL AND EXPERIMENTAL BOTANY}, author={Choudhary, Sunita and Sinclair, Thomas R. and Messina, Carlos D. and Cai, Weiguo and Warner, Dave and Cooper, Mark}, year={2015}, month={Jan}, pages={161–167} }
 @article{devi_taliercio_sinclair_2015, title={Leaf expansion of soybean subjected to high and low atmospheric vapour pressure deficits}, volume={66}, ISSN={["1460-2431"]}, DOI={10.1093/jxb/eru520}, abstractNote={Summary Genotypic differences were found in decrease of leaf expansion with exposure to high vapour pressure deficit. Changes in leaf expansion were associated with down-regulation of expansin and extensin genes.}, number={7}, journal={JOURNAL OF EXPERIMENTAL BOTANY}, author={Devi, M. Jyostna and Taliercio, Earl W. and Sinclair, Thomas R.}, year={2015}, month={Apr}, pages={1845–1850} }
 @article{ghanem_marrou_soltani_kumar_sinclair_2015, title={Lentil Variation in Phenology and Yield Evaluated with a Model}, volume={107}, ISSN={["1435-0645"]}, DOI={10.2134/agronj15.0061}, abstractNote={Lentil (Lens culinaris Medik.) is a major crop highly valued in the food and nutritional security of millions of people, as well as a rotation crop. Lentil is grown in areas facing many environmental constraints from low moisture availability and high temperatures to winter cold at high elevations. The use of an appropriate and robust crop model can offer mechanistic bases for exploring and extrapolating the impact of a given plant trait or crop management across a range of environments. First, we used the generic SSM‐Legumes model to develop a simple and transparent lentil model. The SSM‐Legumes model had a robust predictive capability to assess variation in the phenological development and yield of lentil in three locations in the Middle East (Lebanon and Syria) with large differences in rainfall. The agreement between simulated and observed days to flowering or maturity and yield showed the robustness of the model in predicting lentil growth and yield. Second, we incorporated into SSM‐legumes a submodel allowing a more realistic accounting of crop survival at very low soil water content, resulting in more realistic predictions of lentil growth and yield. Third, we used the model to test the potential for increasing lentil yields by the retention of crop residue on the soil surface to decrease soil evaporation. Our results showed yield increases of up to 25% in all three locations from the retention of previous crop residues.}, number={6}, journal={AGRONOMY JOURNAL}, author={Ghanem, Michel Edmond and Marrou, Helene and Soltani, Afshin and Kumar, Shiv and Sinclair, Thomas R.}, year={2015}, pages={1967–1977} }
 @article{messina_sinclair_hammer_curan_thompson_oler_gho_cooper_2015, title={Limited-Transpiration Trait May Increase Maize Drought Tolerance in the US Corn Belt}, volume={107}, ISSN={["1435-0645"]}, DOI={10.2134/agronj15.0016}, abstractNote={Yield loss due to water deficit is ubiquitous in maize (Zea mays L.) production environments in the United States. The impact of water deficits on yield depends on the cropping system management and physiological characteristics of the hybrid. Genotypic diversity among maize hybrids in the transpiration response to vapor pressure deficit (VPD) indicates that a limited‐transpiration trait may contribute to improved drought tolerance and yield in maize. By limiting transpiration at VPD above a VPD threshold, this trait can increase both daily transpiration efficiency and water availability for late‐season use. Reduced water use, however, may compromise yield potential. The complexity associated with genotype × environment × management interactions can be explored in a quantitative assessment using a simulation model. A simulation study was conducted to assess the likely effect of genotypic variation in limited‐transpiration rate on yield performance of maize at a regional scale in the United States. We demonstrated that the limited‐transpiration trait can result in improved maize performance in drought‐prone environments and that the impact of the trait on maize productivity varies with geography, environment type, expression of the trait, and plant density. The largest average yield increase was simulated for drought‐prone environments (135 g m−2), while a small yield penalty was simulated for environments where water was not limiting (–33 g m−2). Outcomes from this simulation study help interpret the ubiquitous nature of variation for the limited‐transpiration trait in maize germplasm and provide insights into the plausible role of the trait in past and future maize genetic improvement.}, number={6}, journal={AGRONOMY JOURNAL}, author={Messina, Carlos D. and Sinclair, Thomas R. and Hammer, Graeme L. and Curan, Dian and Thompson, Jason and Oler, Zac and Gho, Carla and Cooper, Mark}, year={2015}, pages={1978–1986} }
 @article{shekoofa_rosas-anderson_sinclair_balota_isleib_2015, title={Measurement of Limited-Transpiration Trait under High Vapor Pressure Deficit for Peanut in Chambers and in Field}, volume={107}, ISSN={["1435-0645"]}, DOI={10.2134/agronj14.0570}, abstractNote={Drought is one of the most important environmental factors that limit crop production. Based on controlled‐environment studies, it has been hypothesized that a limited‐transpiration (TRlim) trait under high vapor pressure deficit (VPD) is a mechanism for water conservation leading to yield increase under water‐deficit conditions. The current research objective was to compare expression of TRlim in peanut (Arachis hypogaea L.) observed by whole‐plant measurements in controlled environments and by leaf gas exchange measurements on plants grown in the field. Six peanut genotypes with different breeding backgrounds, that is, wild‐type, commercial cultivars, and advanced breeding lines were studied. Differences were observed among genotypes in their expression of TRlim with increasing VPD in the controlled environment at 31/26°C. Within each breeding background, one genotype showed a linear increase in transpiration with increasing VPD while the other expressed the TRlim trait. In a second set of controlled environment experiments at 36/26°C, none of the six genotypes expressed the TRlim trait. In the field, again none of the genotypes expressed the TRlim trait. The temperature to which the plants were exposed between the two controlled environments and field trial appeared critical in the expression of the TRlim trait of three of the genotypes.}, number={3}, journal={AGRONOMY JOURNAL}, author={Shekoofa, Avat and Rosas-Anderson, Pablo and Sinclair, Thomas R. and Balota, Maria and Isleib, Thomas G.}, year={2015}, pages={1019–1024} }
 @article{riar_sinclair_prasad_2015, title={Persistence of limited-transpiration-rate trait in sorghum at high temperature}, volume={115}, ISSN={["1873-7307"]}, DOI={10.1016/j.envexpbot.2015.02.007}, abstractNote={A limited-transpiration (TRlim) trait has been identified in many crop species, including sorghum (Sorghum bicolor (L.) Moench), that results in restricted transpiration rate under high vapor pressure deficits (VPD). The benefit of TRlim is that under high midday-VPD conditions crop water loss is limited so that there is water conservation and positions the crop to better withstand later-season drought. Previous studies performed at 31 °C found that TRlim was commonly expressed among sorghum genotypes. It was also found that those lines with low VPD breakpoints for expression of the TRlim trait exhibited insensitivity in transpiration rate to being fed silver ions. However, it is uncertain how applicable these previous results obtained at 31 °C might be at higher temperature that may exist at midday in regions where sorghum is commonly grown. The current study tested for the expression of TRlim at 37 °C in 16 sorghum genotypes previously found to express the trait at the lower temperature. Only three of the genotypes sustained expression of TRlim at 37 °C. These results indicate that for environments where temperature may commonly reach or exceed 37 °C, sorghum genotypes have been favored that acclimate to the high temperature by losing the TRlim trait. In conditions in which very high temperatures threaten crop heat stress, those genotypes that lose the TRlim trait at high temperature may be more desirable since increasing transpiration rates at these temperatures can result in leaf cooling. The silver test failed to discriminate genotypes for expression of the TRlim trait at high temperature.}, journal={ENVIRONMENTAL AND EXPERIMENTAL BOTANY}, author={Riar, Mandeep K. and Sinclair, Thomas R. and Prasad, P. V. Vara}, year={2015}, month={Jul}, pages={58–62} }
 @article{marrou_vadez_sinclair_2015, title={Plant Survival of Drought During Establishment: An Interspecific Comparison of Five Grain Legumes}, volume={55}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2014.11.0760}, abstractNote={ABSTRACT}, number={3}, journal={CROP SCIENCE}, author={Marrou, Helene and Vadez, Vincent and Sinclair, Thomas R.}, year={2015}, pages={1264–1273} }
 @article{ghanem_marrou_biradar_sinclair_2015, title={Production potential of Lentil (Lens culinaris Medik.) in East Africa}, volume={137}, ISSN={["1873-2267"]}, DOI={10.1016/j.agsy.2015.03.005}, abstractNote={Lentil (Lens culinaris Medik.) could possibly become a major crop in East Africa due to its many uses as a food and feed. Also, its ability to undertake symbiotic nitrogen fixation is an advantage over cereal crops. This study simulated lentil yield potential in order to determine the geographical areas in East Africa that offer potential for consistent lentil production. Results show that there is potential to further expand the geographical area in which lentil is currently grown in East Africa into Uganda, Kenya, Tanzania and even Somalia. Response to a change in management practices on potential yield of lentil as a result of different sowing dates was also examined. In addition, the effect of phenology on yield potential was examined by comparing a short-season type vs. a long-season type. Delaying sowing alone or in combination with a long-season genotype can result in a high probability of crop yield increase in East Africa. For the long-season genotype, an optimum sowing window was found between June and July (152–229 day of year) for areas to the north of the Rift Valley. Later sowing dates (229–243 day of year) were found to be optimal in southern areas of East Africa. These simulations indicated that selection and breeding for lentil accessions in East Africa should consider changes in plant phenology and/or sowing dates.}, journal={AGRICULTURAL SYSTEMS}, author={Ghanem, Michel Edmond and Marrou, Helene and Biradar, Chandrashekhar and Sinclair, Thomas R.}, year={2015}, month={Jul}, pages={24–38} }
 @article{hall_sinclair_2015, title={Rooting Front and Water Uptake: What You See and Get May Differ}, volume={107}, ISSN={["1435-0645"]}, DOI={10.2134/agronj14.0551}, abstractNote={Soil water extraction is a key function of plant roots, and in drought‐stressed plants the differentiation in the location of roots in the soil and the location of water extraction has usually not been considered. In this experiment with maize (Zea mays L.) grown in columns of drying sand, there was a clear lag in the depth of the water extraction front with respect to the depth of rooting. Under water‐deficit stress at least 10 cm to as much as 30 cm of the terminal segment of maize roots could not extract substrate water at measurable rates. These results showing a large difference in rooting and water extraction‐front depths indicate caution is needed in extrapolating between root position and water extraction.}, number={5}, journal={AGRONOMY JOURNAL}, author={Hall, Antonio J. and Sinclair, Thomas R.}, year={2015}, pages={1766–1770} }
 @article{sinclair_manandhar_belko_riar_vadez_roberts_2015, title={Variation among Cowpea Genotypes in Sensitivity of Transpiration Rate and Symbiotic Nitrogen Fixation to Soil Drying}, volume={55}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2014.12.0816}, abstractNote={ABSTRACT}, number={5}, journal={CROP SCIENCE}, author={Sinclair, Thomas R. and Manandhar, Anju and Belko, Nouhoun and Riar, Mandeep and Vadez, Vincent and Roberts, Philip A.}, year={2015}, pages={2270–2275} }
 @article{marrou_sinclair_metral_2014, title={Assessment of irrigation scenarios to improve performances of Lingot bean (Phaseolus vulgaris) in southwest France}, volume={59}, ISSN={["1873-7331"]}, DOI={10.1016/j.eja.2014.05.006}, abstractNote={In the context of climate change, producing the same amount of food with less water has become a challenge all over the world. This is also true for the Lingot bean production in the area of Castelnaudary of southwest France where market competition with imported bean has made it crucial to achieve high yields to maintain production in the area. The use of an appropriate and robust crop model can help to identify crop management solutions to face such issues. We used SSM-legumes, a crop model generic to legume species, as well as field observations recorded over five years on eight farms of the Castelnaudary area to assess the effect of different irrigation scenarios on bean yield and water consumption. First, it was demonstrated that the SSM-legumes model is robust in simulating the development and growth of Lingot bean in non-stressed or moderately stressed conditions of this region regarding water and nutrient availability. Then, the use of the model to compare irrigation scenarios provided guidance on how to improve irrigation management for Lingot bean production. These results showed that farmers could achieve slightly higher yields with less water by basing irrigation decisions on the water content of the soil.}, journal={EUROPEAN JOURNAL OF AGRONOMY}, author={Marrou, H. and Sinclair, T. R. and Metral, R.}, year={2014}, month={Sep}, pages={22–28} }
 @article{devi_sinclair_chen_carter_2014, title={Evaluation of Elite Southern Maturity Soybean Breeding Lines for Drought-Tolerant Traits}, volume={106}, ISSN={["1435-0645"]}, DOI={10.2134/agronj14.0242}, abstractNote={Breeding efforts in soybean [Glycine max (L.) Merr.] have addressed the challenge of water‐limited yields by incorporating parental stocks which exhibit drought‐tolerant traits. Multiple cycles of empirical selection for improved yielding ability in water‐deficient field environments have produced new generations of adapted breeding lines. However, the impact of this selection process on specific putative drought‐tolerant traits is unknown. The objective of this study was to determine if breeders’ selection of 10 elite lines for high seed yield under dry conditions is associated with the presence of physiological expression of three putative drought‐tolerant traits: (i) limited transpiration rate under high vapor pressure deficit (VPD), (ii) early decrease in transpiration rate with soil drying, and (iii) drought‐tolerant N2 fixation. Greenhouse experiments were undertaken to characterize each genotypes for their phenotype of each of these three traits. Unlike most soybean cultivars, 9 of the 10 elite lines expressed a limited transpiration rate under elevated VPD. The VPD at which transpiration rate became limited was 1.9 kPa or less. There was no difference among genotypes in the threshold for decline in transpiration rate with soil drying, although all genotypes expressed high thresholds indicating an ability to conserve soil water. All lines expressed drought tolerance in their N2 fixation rates, which was superior to that commonly observed in soybean. This study demonstrated that mating of parents that expressed a drought trait and multiple rounds of progeny selection based on improved yield under water‐limited conditions resulted in the elite lines expressing improved drought traits.}, number={6}, journal={AGRONOMY JOURNAL}, author={Devi, Jyostna Mura and Sinclair, Thomas R. and Chen, Pengyin and Carter, Thomas E.}, year={2014}, pages={1947–1954} }
 @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{sunita_sinclair_messina_cooper_2014, title={Hydraulic Conductance of Maize Hybrids Differing in Transpiration Response to Vapor Pressure Deficit}, volume={54}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2013.05.0303}, abstractNote={ABSTRACT}, number={3}, journal={CROP SCIENCE}, author={Sunita, Choudhary and Sinclair, Thomas R. and Messina, Carlos D. and Cooper, Mark}, year={2014}, pages={1147–1152} }
 @article{choudhary_sinclair_2014, title={Hydraulic conductance differences among sorghum genotypes to explain variation in restricted transpiration rates}, volume={41}, ISSN={["1445-4416"]}, DOI={10.1071/fp13246}, abstractNote={

Sorghum (Sorghum bicolor L.) is an important crop for production in dryland regions of the globe. Traits identified in many sorghum lines that apparently make them adapted for dryland conditions are restricted transpiration rate both early in the soil drying cycle and under high atmospheric vapour pressure deficit. It was hypothesised that these responses could be a result of differences in hydraulic conductance of the plants: those with low hydraulic conductance would be more likely to express restricted transpiration rates. The location of the lower hydraulic conductance in the plant could also be important with a low conductance in the leaf xylem to stomata pathway possibly being more advantageous than in the root. In this study, the amount and location of the hydraulic conductance was measured in 20 sorghum genotypes. Those genotypes that expressed an early decrease in transpiration rate with soil drying had greater plant and leaf hydraulic conductance than those genotypes that had the later decreases in transpiration rate, which was in contrast with what was hypothesised. However, sorghum genotypes that segregated between two groups based on expression of a maximum transpiration trait also segregated based on their hydraulic conductance. Those genotypes that expressed the maximum transpiration trait had lower hydraulic conductance for the intact plant and in the leaves.
}, number={3}, journal={FUNCTIONAL PLANT BIOLOGY}, author={Choudhary, Sunita and Sinclair, Thomas R.}, year={2014}, pages={270–275} }
 @article{shekoofa_balota_sinclair_2014, title={Limited-transpiration trait evaluated in growth chamber and field for sorghum genotypes}, volume={99}, ISSN={["1873-7307"]}, DOI={10.1016/j.envexpbot.2013.11.018}, abstractNote={Sorghum [Sorghum bicolor (L.) Moench] is commonly grown in water-limited environments throughout the world. Plant traits could be useful allowing for early-season water conservation so that more water is available for use later in the season when drought is most likely to develop. One trait that might result in early-season water conservation is the expression of a limited-transpiration trait defined as a limitation on further increases in transpiration rate (TR) under high vapor pressure deficit (VPD) conditions. The objective of this study was to compare the expression of the limited-TR trait measured for nine sorghum genotypes under both controlled chamber and field conditions. In the growth chamber, plant TR was measured over a range of imposed VPD to provide a direct measure of plant transpiration under high VPD. In the field, stomatal conductance (gs) was measured over the daily cycle, which resulted in a range of ambient VPD. A decrease in gs under high VPD was evidence of the limited-TR trait. This study identified three sorghum genotypes (DKS 36-06, DKS 44-20, and DKS 54-00) that did not show any limitation on water loss at high VPD in either the greenhouse or field. On the other hand, four genotypes (BTX 2752, SC 599, SC 982, and B 35) exhibited the limited-TR trait in the growth chamber with breakpoints in response to VPD at values of 2.33 kPa and above. These four genotypes also expressed a breakpoint in gs in response to increasing VPD in the field. Two genotypes (TX ARG 1, TX 436) that differed between the growth chamber and field showed consistency in response on close examination of the field results. The overall general correspondence within genotypes between the controlled chamber and the field in expression or lack of expression of a breakpoint in response to increasing VPD demonstrated the possibility of selecting genotypes for the TRlim trait under differing environmental conditions.}, journal={ENVIRONMENTAL AND EXPERIMENTAL BOTANY}, author={Shekoofa, A. and Balota, M. and Sinclair, T. R.}, year={2014}, month={Mar}, pages={175–179} }
 @article{sinclair_wherley_dukes_cathey_2014, title={Penman's sink-strength model as an improved approach to estimating plant canopy transpiration}, volume={197}, ISSN={["1873-2240"]}, DOI={10.1016/j.agrformet.2014.06.012}, abstractNote={The Penman energy balance equation has become a common approach to estimating the evaporation of plant canopies. Unfortunately, implementation of the energy balance equation requires various assumptions and empiricisms, including “crop coefficients”, so that in practice the Penman equation is used as a framework in which to apply empirical approximations. These limitations are reviewed in this paper. An alternative to the energy balance approach suggested by Penman was a “sink strength” model in which the gradient in vapor pressure was considered the prime driver of plant water loss. In this paper, the sink strength model is developed for determining plant canopy transpiration based on explicitly defined properties of the plants. The key variables are the carbon assimilation pathway of photosynthesis and the biochemical composition of the plant material being synthesized. These two parameters define the transpiration efficiency coefficient and radiation use efficiency that are required in the calculation of transpiration. Also, it is necessary to define a weighted vapor pressure gradient for transpiration when making estimates of the amount of transpiration on a daily basis. The derived expression of the sink strength model was used to compare predicted transpiration with measured values of four turf grass species measured over three years. A close linear correlation was observed for all grasses (P < 0.0001). However, there was an indication that the grasses may vary slightly in their radiation use efficiencies, which with measurement of photosynthetic capacity would further improve the predicted transpiration rates. The ability to directly compute transpiration from explicitly defined variables based on plant traits offers an attractive alternative to the Penman energy balance approach.}, journal={AGRICULTURAL AND FOREST METEOROLOGY}, author={Sinclair, Thomas R. and Wherley, Benjamin G. and Dukes, Michael D. and Cathey, Sarah E.}, year={2014}, month={Oct}, pages={136–141} }
 @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{devi_sinclair_beebe_rao_2013, title={Comparison of common bean (Phaseolus vulgaris L.) genotypes for nitrogen fixation tolerance to soil drying}, volume={364}, ISSN={["1573-5036"]}, DOI={10.1007/s11104-012-1330-4}, number={1-2}, journal={PLANT AND SOIL}, author={Devi, Mura Jyostna and Sinclair, Thomas R. and Beebe, Stephen E. and Rao, Idupulapati M.}, year={2013}, month={Mar}, pages={29–37} }
 @article{vadez_soltani_sinclair_2013, title={Crop simulation analysis of phenological adaptation of chickpea to different latitudes of India}, volume={146}, ISSN={["1872-6852"]}, DOI={10.1016/j.fcr.2013.03.005}, abstractNote={Plant phenology is a critical component of crop adaptation, especially under environmental conditions that don’t allow crop growth for unlimited periods. In chickpea (Cicer arietinum L.), which faces terminal drought and increasing temperature at the end of its growing season, it is widely considered that longer duration genotypes are needed for the higher latitudes of India and shorter duration genotypes for lower latitudes. Here, we compare two sets of genotypes bred in two locations varying in latitude (high latitude: Hisar, Haryana, India; low latitude: ICRISAT, Andhra Pradesh, India) for the number of biological days from emergence to flowering (EMR1) and for the grain filling period (R5R7). Biological days referred to days where the phenological development was optimal and therefore provides a measure of thermal time. Using a robust crop simulation model, the optimum EMR1 and R5R7 were determined for various locations. As expected, EMR1 and R5R7 values of genotypes bred for low latitude were lower than those bred for high latitude. However, predicted yields of these two sets of genotypes were similar when simulated for each of the two environments, yields being overall higher at Hisar. Results for the combined set of genotypes at each location predicted a similar optimum EMR1 to achieve maximum yield at each location: 44.3 biological days at Hisar and 43.5 biological days at ICRISAT. Derivation of optimum EMR1 across a total of ten locations in India indicated a wider range (37.2–51.8 biological days), although in eight locations the optimum EMR1 was in a narrower range (39.4–47.3 biological days). The differences in EMR1 across locations did not correspond to their latitudinal differences. Instead, rainfall through the growing season was significantly and positively related (R2 = 0.55) to optimum EMR1. These results indicate that the breeding for optimum EMR1 of chickpea in India needs to be focused on expected rainfall for a region, and that an optimum EMR1 of about 43 biological days would likely fit most of the environments.}, journal={FIELD CROPS RESEARCH}, author={Vadez, V. and Soltani, A. and Sinclair, T. R.}, year={2013}, month={May}, pages={1–9} }
 @article{shekoofa_devi_sinclair_holbrook_isleib_2013, title={Divergence in Drought-resistance Traits among Parents of Recombinant Peanut Inbred Lines}, volume={53}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2013.03.0153}, abstractNote={ABSTRACT}, number={6}, journal={CROP SCIENCE}, author={Shekoofa, Avat and Devi, J. Mura and Sinclair, Thomas R. and Holbrook, Corley C. and Isleib, Thomas G.}, year={2013}, pages={2569–2576} }
 @article{choudhary_sinclair_prasad_2013, title={Hydraulic conductance of intact plants of two contrasting sorghum lines, SC15 and SC1205}, volume={40}, ISSN={["1445-4416"]}, DOI={10.1071/fp12338}, abstractNote={

Low plant hydraulic conductance has been hypothesised as an approach to decrease the rate of soil water use, resulting in soil water conservation for use during late season water deficits. The impact of leaf hydraulic conductance (Kleaf) on water use characteristics was explored by comparing two sorghum (Sorghum bicolor (L.) Moench) genotypes that had been found to differ in Kleaf. Genotype SC15 had a much lower leaf conductance than genotype SC1205. Four sets of experiments were undertaken to extend the comparison to the impact of differences in Kleaf on the plant water budget. (1) Measurements of hydraulic conductance of intact plants confirmed that leaf conductance of SC15 was lower than that of SC1205. (2) The low leaf conductance of SC15 was associated with a decrease in transpiration during soil drying at a higher soil water content than that of SC1205. (3) SC15 had a restricted transpiration rate at vapour pressure deficits (VPD) above 2.1 kPa, whereas SC1205 did not. (4) Treatment with aquaporin inhibitors showed substantial differences in the sensitivity of the transpiration response between the genotypes. These results demonstrated that low Kleaf in SC15 was associated with conservative water use by restricting transpiration at higher soil water content during soil drying and under high VPD. Tests with inhibitors indicate that these differences may be linked to differences between their aquaporin populations. The differences between the two genotypes indicated that the traits exhibited by SC15 would be desirable in environments where soil water deficits develop.
}, number={7}, journal={FUNCTIONAL PLANT BIOLOGY}, author={Choudhary, Sunita and Sinclair, Thomas R. and Prasad, P. V. Vara}, year={2013}, pages={730–738} }
 @article{choudhary_mutava_shekoofa_sinclair_prasad_2013, title={Is the Stay-Green Trait in Sorghum a Result of Transpiration Sensitivity to Either Soil Drying or Vapor Pressure Deficit?}, volume={53}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2013.01.0043}, abstractNote={ABSTRACT}, number={5}, journal={CROP SCIENCE}, author={Choudhary, Sunita and Mutava, Raymond N. and Shekoofa, Avat and Sinclair, Thomas R. and Prasad, P. V. Vara}, year={2013}, pages={2129–2134} }
 @article{gholipoor_sinclair_raza_loeffler_cooper_messina_2013, title={Maize Hybrid Variability for Transpiration Decrease with Progressive Soil Drying}, volume={199}, ISSN={["1439-037X"]}, DOI={10.1111/j.1439-037x.2012.00530.x}, abstractNote={Abstract}, number={1}, journal={JOURNAL OF AGRONOMY AND CROP SCIENCE}, author={Gholipoor, M. and Sinclair, T. R. and Raza, M. A. S. and Loeffler, C. and Cooper, M. and Messina, C. D.}, year={2013}, month={Feb}, pages={23–29} }
 @article{cathey_sinclair_mackowiak_2013, title={NITROGEN LIMITATION OF RHIZOMA PEANUT GROWTH}, volume={36}, ISSN={["0190-4167"]}, DOI={10.1080/01904167.2012.739250}, abstractNote={Rhizoma peanut (Arachis glabrata) is a forage and groundcover crop of increasing importance in the southeastern United States, but little is known of its nitrogen (N) requirement for optimal production, or if this requirement is being met through symbiotic nitrogen fixation. Nitrogen fertilization greenhouse experiments were performed with Florigraze and Ecoturf genotypes and response measured by shoot production, nodulation, nitrogenase activity, shoot N concentrations, and N accumulation. Rhizome N concentrations with and without N fertilization were also evaluated in the field. From the two greenhouse studies, we found a saturating response to N fertilization between 11 and 23 kg N ha-1 during the 11-week evaluation period. In both the greenhouse, and to a lesser extent, the field experiment, N accumulation was found to increase with increased N fertilization, which indicates that N2-fixation may not provide the necessary N for optimal shoot production.}, number={2}, journal={JOURNAL OF PLANT NUTRITION}, author={Cathey, Sarah E. and Sinclair, Thomas R. and Mackowiak, Cheryl L.}, year={2013}, month={Jan}, pages={311–328} }
 @article{devi_sinclair_2013, title={Nitrogen Fixation Drought Tolerance of the Slow-Wilting Soybean PI 471938}, volume={53}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2013.02.0095}, abstractNote={ABSTRACT}, number={5}, journal={CROP SCIENCE}, author={Devi, M. J. and Sinclair, T. R.}, year={2013}, pages={2072–2078} }
 @article{devi_rowland_payton_faircloth_sinclair_2013, title={Nitrogen fixation tolerance to soil water deficit among commercial cultivars and breeding lines of peanut}, volume={149}, ISSN={["0378-4290"]}, DOI={10.1016/j.fcr.2013.04.026}, abstractNote={Peanut is often grown in the U.S. on sandy soil with limited water holding capacity. Since nitrogen fixation activity of other grain legume species, and some peanut cultivars, has been found to be especially sensitive to soil drying, yield improvement may be possible by identifying and/or breeding cultivars with nitrogen fixation resistance to water-deficit conditions. A key in this approach will be the use of screens to identify genotypes that may express drought resistance. Two screens of differing experimental sophistication were explored in this study as potential tools to compare genotypes. The first screen was done in the greenhouse using intact plants in a flow-though acetylene reduction system to measure nitrogen fixation response to soil drying over about two weeks. Ten commercial cultivars were tested and the only significant difference in nitrogen fixation activity was between Georgia 06G and York. The threshold for the decline in the nitrogen fixation rate averaged at a relative high value of 0.37 but Georgia 06G had a relatively low value of 0.28. These thresholds are greater than have been reported for nitrogen fixation tolerance in other species. The second, less sensitive screen that can be applied to a much larger number of genotypes was done in the field by measuring nitrogen accumulation over 2–3 wks of growth on limited available soil water. There were no differences in nitrogen-to-mass accumulation ratio among the commercial cultivars during two limited-water experiments. However, data collected from the field on several breeding lines from India indicated a consistency in the identification of nitrogen fixation in the greenhouse experiment and field experiments.}, journal={FIELD CROPS RESEARCH}, author={Devi, Joystna M. and Rowland, Diane L. and Payton, Paxton and Faircloth, Wilson and Sinclair, Thomas R.}, year={2013}, month={Aug}, pages={127–132} }
 @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{gholipoor_choudhary_sinclair_messina_cooper_2013, title={Transpiration Response of Maize Hybrids to Atmospheric Vapour Pressure Deficit}, volume={199}, ISSN={["1439-037X"]}, DOI={10.1111/jac.12010}, abstractNote={Abstract}, number={3}, journal={JOURNAL OF AGRONOMY AND CROP SCIENCE}, author={Gholipoor, M. and Choudhary, S. and Sinclair, T. R. and Messina, C. D. and Cooper, M.}, year={2013}, month={Jun}, pages={155–160} }
 @article{cathey_kruse_sinclair_dukes_2013, title={Transpiration and visual appearance of warm season turfgrasses during soil drying}, volume={89}, ISSN={["0098-8472"]}, DOI={10.1016/j.envexpbot.2012.12.004}, abstractNote={Warm-season turfgrasses may be subjected to increasing drought as future urban irrigation regulations become more restrictive. Species differences in water use and transpiration response to drying soil may be exploited in the future to increase survival and maintain green color under drying soil conditions. This study was undertaken to provide background documentation on the sensitivity to soil–water deficit of three warm-season grasses: ‘Argentine’ bahiagrass (Paspalum notatum); ‘Floratam’ St. Augustinegrass (Stenotaphrum secundatum), and ‘Empire’ zoysiagrass (Zoysia japonica). Each of these turfgrasses demonstrated a two-phased linear transpiration response to gradually drying soil as expressed by a normalized ratio between the transpiration rates of drought stressed to well-watered plants (NTR). In this study, well-watered bahiagrass used 30% more water on a daily basis than did well-watered St. Augustinegrass or zoysiagrass. However, under drought, the three grass species transpired the same amount of water during the soil drying period up until NTR to 0.1. Since bahiagrass reached an NTR of 0.1 at 10.3 days versus 12.7 and 13.0 days for St. Augustinegrass and zoysiagrass, respectively, bahiagrass demonstrated a more rapid water loss rate during the drying period. The fraction of transpirable soil water (FTSW) remaining in the soil at the breakpoints for bahiagrass, St. Augustinegrass and zoysiagrass were 0.13, 0.16, and 0.19, respectively, in 2010, but were 0.18, 0.30, and 0.22, respectively, under slightly warmer conditions in 2011. The consistently low FTSW breakpoint for bahiagrass means that compared to the other species, bahiagrass continues to use water at a high rate late into the soil drying cycle before conserving soil water by decreasing stomatal conductance. That is, bahiagrass is likely to be subjected to greater soil–water deficits in lengthy droughts and needs mechanisms to better survive these droughts. The differences in breakpoints by year may be due to a combination of soil factors and temperature differences in the greenhouse.}, journal={ENVIRONMENTAL AND EXPERIMENTAL BOTANY}, author={Cathey, Sarah E. and Kruse, Jason K. and Sinclair, Thomas R. and Dukes, Michael D.}, year={2013}, month={May}, pages={36–43} }
 @article{sadok_gilbert_raza_sinclair_2012, title={Basis of Slow-Wilting Phenotype in Soybean PI 471938}, volume={52}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2011.11.0622}, abstractNote={ABSTRACT}, number={3}, journal={CROP SCIENCE}, author={Sadok, Walid and Gilbert, Matthew E. and Raza, M. Aown S. and Sinclair, Thomas R.}, year={2012}, pages={1261–1269} }
 @misc{sinclair_2012, title={Empires of food: Feast, famine, and the rise and fall of civilizations}, volume={86}, number={2}, journal={Agricultural History}, author={Sinclair, T.}, year={2012}, pages={102–103} }
 @article{gholipoor_sinclair_prasad_2012, title={Genotypic variation within sorghum for transpiration response to drying soil}, volume={357}, ISSN={["0032-079X"]}, DOI={10.1007/s11104-012-1140-8}, number={1-2}, journal={PLANT AND SOIL}, author={Gholipoor, Manoochehr and Sinclair, Thomas R. and Prasad, P. V. Vara}, year={2012}, month={Aug}, pages={35–40} }
 @article{carpentieri-pipolo_pipolo_abdel-haleem_boerma_sinclair_2012, title={Identification of QTLs associated with limited leaf hydraulic conductance in soybean}, volume={186}, ISSN={["0014-2336"]}, DOI={10.1007/s10681-011-0535-6}, number={3}, journal={EUPHYTICA}, author={Carpentieri-Pipolo, V. and Pipolo, A. E. and Abdel-Haleem, H. and Boerma, H. R. and Sinclair, T. R.}, year={2012}, month={Aug}, pages={679–686} }
 @article{soltani_sinclair_2012, title={Identifying plant traits to increase chickpea yield in water-limited environments}, volume={133}, ISSN={["1872-6852"]}, DOI={10.1016/j.fcr.2012.04.006}, abstractNote={Average chickpea (Cicer arietinum L.) yield is low in major producer countries, which in nearly all cases is a consequence of water-deficit conditions. A first step in increasing crop yield under drought is to identify drought traits that are likely to be beneficial. In this study, we examined potential benefits of six modified drought traits in chickpea in two contrasting water-limited environments. Simulations were performed over 30 seasons for two soil depths (120 and 80 cm) at Tabriz and Gonbad, Iran, representing the environmental diversity among major chickpea producing areas. Delayed stomata closure with respect to soil drying resulted in decreased yield. A slower rate of leaf development did not lead to yield improvement. Four other traits increased crop yield. Increased depth of water extraction from the soil provided the greatest yield increase that varied from 14% in a deep soil at Gonbad (wetter environment) to 45% in a shallower soil at Tabriz (drier environment). Slower rate of growth (crop mass production) was the second important trait which resulted in 6–8% yield increase in 120-cm-soil and 21% yield increase in 80-cm-soil. The priority of other traits to increase crop yield depended on soil depth. In 120-cm-soil, reduced maximum transpiration rate improved crop yield (5–7%). Yield enhancement as a result of early stomata closure with respect to soil drying was ≤3% in this soil. In 80-cm-soil, however, early stomata closure with respect to soil drying was the third most beneficial drought traits in increasing yield (13–16%). Reduced maximum transpiration rate resulted in 3 and 6% yield increase at 80-cm-soil in Tabriz and Gonbad, respectively. It was concluded that deeper rooting, slower rate of growth, early stomata closure and reduced maximum transpiration rate are key target traits for genetic improvement in chickpea in water-limited environments with terminal droughts.}, journal={FIELD CROPS RESEARCH}, author={Soltani, Afshin and Sinclair, Thomas R.}, year={2012}, month={Jul}, pages={186–196} }
 @article{sinclair_2012, title={Is transpiration efficiency a viable plant trait in breeding for crop improvement?}, volume={39}, ISSN={["1445-4416"]}, DOI={10.1071/fp11198}, abstractNote={

Increased transpiration efficiency – commonly the ratio of mass accumulation to transpiration – is often suggested as a critical opportunity for genetic improvement for increased crop yields in water-limited environments. However, close inspection of transpiration efficiency (TE) shows that it is a complex term that is explicitly dependent upon both physiological and environmental variables. Physiological variables include leaf photosynthetic capacity, biochemical composition of the plant productions and possible hydraulic limitation on water flow in the plant. Environmental variables include atmospheric CO2 concentration and atmospheric vapour pressure deficit. To complicate the resolution of transpiration efficiency, a weighted integration over the daily cycle and over the dates of interest needs to be resolved. Consequently, it is concluded that transpiration efficiency is not a variable easily resolved for use in many breeding programs. Instead, component traits contributing to TE need to be studied to increase the effective use of available water through the growing season to ultimately maximise growth and yield of the crop.
}, number={5}, journal={FUNCTIONAL PLANT BIOLOGY}, author={Sinclair, Thomas R.}, year={2012}, pages={359–365} }
 @article{abdel-haleem_carter_purcell_king_ries_chen_schapaugh_sinclair_boerma_2012, title={Mapping of quantitative trait loci for canopy-wilting trait in soybean (Glycine max L. Merr)}, volume={125}, DOI={10.1007/s00122-012-1876-9}, abstractNote={Drought stress adversely affects [Glycine max (L.) Merr] soybean at most developmental stages, which collectively results in yield reduction. Little information is available on relative contribution and chromosomal locations of quantitative trait loci (QTL) conditioning drought tolerance in soybean. A Japanese germplasm accession, PI 416937, was found to possess drought resistance. Under moisture-deficit conditions, PI 416937 wilted more slowly in the field than elite cultivars and has been used as a parent in breeding programs to improve soybean productivity. A recombinant inbred line (RIL) population was derived from a cross between PI 416937 and Benning, and the population was phenotyped for canopy wilting under rain-fed field conditions in five distinct environments to identify the QTL associated with the canopy-wilting trait. In a combined analysis over environments, seven QTL that explained 75 % of the variation in canopy-wilting trait were identified on different chromosomes, implying the complexity of this trait. Five QTL inherited their positive alleles from PI 416937. Surprisingly, the other two QTL inherited their positive alleles from Benning. These putative QTL were co-localized with other QTL previously identified as related to plant abiotic stresses in soybean, suggesting that canopy-wilting QTL may be associated with additional morpho-physiological traits in soybean. A locus on chromosome 12 (Gm12) from PI 416937 was detected in the combined analysis as well as in each individual environment, and explained 27 % of the variation in canopy-wilting. QTL identified in PI 416937 could provide an efficient means to augment field-oriented development of drought-tolerant soybean cultivars.}, number={5}, journal={Theoretical and Applied Genetics}, author={Abdel-Haleem, H. and Carter, T. E. and Purcell, L. C. and King, C. A. and Ries, L. L. and Chen, P. Y. and Schapaugh, W. and Sinclair, T. R. and Boerma, H. R.}, year={2012}, pages={837–846} }
 @article{vadez_soltani_sinclair_2012, title={Modelling possible benefits of root related traits to enhance terminal drought adaptation of chickpea}, volume={137}, ISSN={["1872-6852"]}, DOI={10.1016/j.fcr.2012.07.022}, abstractNote={Chickpea is cultivated at the end of the rain in tropical and sub-tropical regions like in India. Crop growth depends on the soil moisture contained in the soil profile, commonly leading to terminal water deficits. The past three decades of research have focused on improving rooting traits, with a particular focus on the speed of root extension in the soil, making the assumption that this would lead to more water extraction. Here, we used a robust crop simulation model to assess genetic and management modifications that would affect water availability to the crop. Against expectations, increasing the rate of depth of root extension to 30 mm day−1 from a baseline of 17 mm day−1, to reflect the characteristics of an existing root trait quantitative trait locus (QTL) on linkage group 5 of chickpea, brought about a yield penalty in all situations (4–6%), especially in locations where the in-season rainfall was low (up to a 15% yield penalty). By contrast, modifying soil characteristics by increasing the depth of effective water extraction from 1000 mm to 1200 mm led to yield increases in all situations (8–12%) as a result of greater water available at the end of the growing season. Changing the rate of leaf area development rate associated with the root QTL locus on LG5, had no impact on yield except for a yield increase at the two highest yielding locations. The greatest changes in yield were obtained by irrigating the crop with 30 mm at R5 (beginning of seed growth). The average yield gain across all locations was 29% and the high yield benefit was achieved across all yield levels. These results indicated that some benefit would come from growing the crop in soil with a higher depth of effective water extraction, which may require faster root growth in very low rainfall environments, but the greatest yield benefit would result from modest irrigation at R5.}, journal={FIELD CROPS RESEARCH}, author={Vadez, V. and Soltani, A. and Sinclair, T. R.}, year={2012}, month={Oct}, pages={108–115} }
 @article{soltani_sinclair_2012, title={Optimizing chickpea phenology to available water under current and future climates}, volume={38}, ISSN={["1873-7331"]}, DOI={10.1016/j.eja.2011.11.010}, abstractNote={Average chickpea (Cicer arietinum L.) yield remains low in major producing countries due mainly to inadequate water, and a crucial issue for the future of these countries is the likely yield response to changing climate. In this study, we simulated potential benefits of modified phenology in chickpea in two contrasting water-limited environments under current and future (+4 °C increase in temperature, 15% lower precipitation and CO2 concentration of 700 μmol mol−1) climates. Long-term simulations were performed for Tabriz (39 years) and Gonbad (35 years) that represent major chickpea producing areas of Iran. Mean yield increased 42% in Tabriz (from 138 to 196 g m−2) and 21% in Gonbad (from 181 to 218 g m−2) under the future climate. Greater increases in Tabriz were due to the possibility of earlier sowing dates (21 days) under future climates. Earlier maturity as a result of 20% shorter vegetative period from emergence to flowering significantly increased crop yield in both locations under current (13–14%) and future (18–20%) climates. However, earlier maturity via shorter grain filling period did not result in yield increase. A combination of 20% shorter vegetative growth and 20% longer grain filling period led to even higher yields (17–24%) in both locations and under current and future climates.}, journal={EUROPEAN JOURNAL OF AGRONOMY}, author={Soltani, Afshin and Sinclair, Thomas R.}, year={2012}, month={Apr}, pages={22–31} }
 @article{yang_sinclair_zhu_messina_cooper_hammer_2012, title={Temperature effect on transpiration response of maize plants to vapour pressure deficit}, volume={78}, ISSN={["1873-7307"]}, DOI={10.1016/j.envexpbot.2011.12.034}, abstractNote={Breeding for drought tolerance can benefit from a better understanding of possible responses of transpiration to various environmental variables. Temperature and vapour pressure deficit (VPD) are two important factors influencing stomatal conductance and transpiration. In this study, maize (Zea mays L.) plants of four hybrids were grown under three day/night temperature regimes (30/26, 26/22 and 22/18 °C) in glasshouses, and the response of transpiration rate to changes in atmospheric VPD was measured at two different temperatures in a growth chamber. For all the hybrids examined, increases in transpiration rate with increasing VPD were similar and well described by a two-segment linear regression. There was little further increase in transpiration as VPD increased beyond a breakpoint. When measured at high temperature, the breakpoint in transpiration response to VPD occurred at significantly higher VPD and transpiration rate than at low temperature. The effect of growth temperature on transpiration was evident when plants were grown at low temperature (22/18 °C) and measured at higher temperature (30 °C). However, on the second day under the measurement temperature, the transpiration rate of these plants increased to the same level as those grown in higher day/night temperature environments. Limitation on transpiration at high VPD is a promising trait that could be incorporated into breeding programs to improve drought tolerance in maize.}, journal={ENVIRONMENTAL AND EXPERIMENTAL BOTANY}, author={Yang, Zongjian and Sinclair, Thomas R. and Zhu, Maggie and Messina, Carlos D. and Cooper, Mark and Hammer, Graeme L.}, year={2012}, month={May}, pages={157–162} }
 @misc{sinclair_vadez_2012, title={The future of grain legumes in cropping systems}, volume={63}, ISSN={["1836-5795"]}, DOI={10.1071/cp12128}, abstractNote={

Grain legume production is increasing worldwide due to their use directly as human food, feed for animals, and industrial demands. Further, grain legumes have the ability to enhance the levels of nitrogen and phosphorus in cropping systems. Considering the increasing needs for human consumption of plant products and the economic constraints of applying fertiliser on cereal crops, we envision a greater role for grain legumes in cropping systems, especially in regions where accessibility and affordability of fertiliser is an issue. However, for several reasons the role of grain legumes in cropping systems has often received less emphasis than cereals. In this review, we discuss four major issues in increasing grain legume productivity and their role in overall crop production: (i) increased symbiotic nitrogen fixation capacity, (ii) increased phosphorus recovery from the soil, (iii) overcoming grain legume yield limitations, and (iv) cropping systems to take advantage of the multi-dimensional benefits of grain legumes.
}, number={6}, journal={CROP & PASTURE SCIENCE}, author={Sinclair, Thomas R. and Vadez, Vincent}, year={2012}, pages={501–512} }
 @article{devi_sadok_sinclair_2012, title={Transpiration response of de-rooted peanut plants to aquaporin inhibitors}, volume={78}, ISSN={["0098-8472"]}, DOI={10.1016/j.envexpbot.2012.01.001}, abstractNote={Selected genotypes of peanut (Arachis hypogaea L.) have been identified that show constrained transpiration rates (TR) at high atmospheric vapor pressure deficits (VPD) in contrast to genotypes that exhibit continually increasing TR with increasing VPD. The constraint of TR has been proposed as a putative trait for soil water conservation and improved crop performance during late-season water deficits. In soybean (Glycine max (L.) Merr.), limited TR at high VPD has been found to be related to a decreased hydraulic conductance in leaves. A different population of water-transport-mediating proteins, i.e., aquaporins (AQP), was indicated in soybean by measuring the response of shoot TR to treatment with a silver AQP inhibitor. The objective of this study was to test the shoots of four peanut genotypes for a transpiration response when treated with four inhibitors of AQP, which appear to have differing modes of action in inhibiting AQP. Transpiration rate of all four genotypes were equally sensitive to exposure to cycloheximide and mercuric chloride (HgCl2). Treatment of the shoots of three genotypes (ICGS 44, TMV 2 and ICGV 86699) with silver nitrate (AgNO3) and hydrogen tetrachloroaurate (HAuCl4) resulted in decreased TR while treatment of genotype ICGV 91284, which had constrained TR at high VPD, resulted in little or no decrease of TR. In fact, the AgNO3 treatment of this fourth genotype resulted in a stimulation of TR at higher AgNO3 concentrations. Among the three genotypes with TR not constrained at high VPD, two genotypes had less decrease in TR with HAuCl4 treatment than the third genotype. These results identified major differences in shoot response to AQP inhibitors, which were hypothesized to indicate different populations of AQP in the leaves of these peanut genotypes.}, journal={ENVIRONMENTAL AND EXPERIMENTAL BOTANY}, author={Devi, M. Jyostna and Sadok, Walid and Sinclair, Thomas R.}, year={2012}, month={May}, pages={167–172} }
 @article{soltani_sinclair_2011, title={A simple model for chickpea development, growth and yield}, volume={124}, ISSN={["1872-6852"]}, DOI={10.1016/j.fcr.2011.06.021}, abstractNote={Chickpea (Cicer arietinum L.) yield is unstable and low in major producer countries. A robust crop model can assist in evaluation of possible genetic improvements and cultural management practices to improve yield. The objectives of this study were to develop and test a chickpea simulation model that could be used across a wide range of environments. This model simulates phenological development, leaf development and senescence, mass partitioning, plant nitrogen balance, yield formation and soil water balance. Responses of crop processes to environmental factors of solar radiation, photoperiod, temperature, nitrogen and water availability, and genotype differences were included in the model. The model uses a daily time step and readily available weather and soil information. The model was tested using independent data from a wide range of growth and environmental conditions. In most cases, simulated grain yield were similar to observed yield (ranging from 20 to 379 g m−2) with a root mean square root of 26 g m−2 (15% of average measured yield). It was concluded that the model generality, i.e., constant parameters for genotypes across locations, and applicability to a wide range of environmental conditions factors made this model especially useful.}, number={2}, journal={FIELD CROPS RESEARCH}, author={Soltani, Afshin and Sinclair, Thomas R.}, year={2011}, month={Nov}, pages={252–260} }
 @misc{sinclair_2011, title={Challenges in breeding for yield increase for drought}, volume={16}, ISSN={["1878-4372"]}, DOI={10.1016/j.tplants.2011.02.008}, abstractNote={Crop genetic improvement for environmental stress at the molecular and physiological level is very complex and challenging. Unlike the example of the current major commercial transgenic crops for which biotic stress tolerance is based on chemicals alien to plants, the complex, redundant and homeostatic molecular and physiological systems existing in plants must be altered for drought tolerance improvement. Sophisticated tools must be developed to monitor phenotype expression at the crop level to characterize variation among genotypes across a range of environments. Once stress-tolerant cultivars are developed, regional probability distributions describing yield response across years will be necessary. This information can then aid in identifying environmental conditions for positive and negative responses to genetic modification to guide farmer selection of stress-tolerant cultivars.}, number={6}, journal={TRENDS IN PLANT SCIENCE}, author={Sinclair, Thomas R.}, year={2011}, month={Jun}, pages={289–293} }
 @article{gholipoor_sinclair_2011, title={Historical changes of temperature and vapor pressure deficit during the crop growing season in Iran}, volume={5}, number={2}, journal={International Journal of Plant Production}, author={Gholipoor, M. and Sinclair, T. R.}, year={2011}, pages={195–205} }
 @article{pachepsky_shelton_mclain_patel_mandrell_2011, title={IRRIGATION WATERS AS A SOURCE OF PATHOGENIC MICROORGANISMS IN PRODUCE: A REVIEW}, volume={113}, ISBN={["978-0-12-386473-4"]}, ISSN={["0065-2113"]}, DOI={10.1016/b978-0-12-386473-4.00007-5}, journal={ADVANCES IN AGRONOMY, VOL 113}, author={Pachepsky, Yakov and Shelton, Daniel R. and McLain, Jean E. T. and Patel, Jitendra and Mandrell, Robert E.}, year={2011}, pages={73–138} }
 @article{wherley_sinclair_dukes_schreffler_2011, title={Nitrogen and Cutting Height Influence Root Development during Warm-Season Turfgrass Sod Establishment}, volume={103}, ISSN={["0002-1962"]}, DOI={10.2134/agronj2011.0146}, abstractNote={Effective water conservation in the landscape requires identification of cultural management practices that maximize the genetic rooting potential of establishing turfgrass sod. Nitrogen is critical for successful turfgrass establishment; however, there has recently been debate over whether to restrict N fertilization during summer periods in parts of Florida and the United States. This study was undertaken to examine within four warm‐season turfgrass species, the relative influences of cutting height and N fertility on the (i) rate of root extension and (ii) root biomass produced over a 10‐wk period. ‘Tifway 419’ bermudagrass (Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt Davy), ‘Empire’ zoysiagrass (Zoysia japonica Steud.), ‘Argentine’ bahiagrass (Paspalum notatum Flugge), and ‘Floratam’ St. Augustinegrass (Stenotaphrum secundatum Walt. Kuntze) were established from 10‐cm diam. by 5‐cm deep plugs of turfgrass sod into 90‐cm tall, clear acrylic tubes. Experimental treatments were arranged in a complete factorial that was repeated over two growing seasons. Rates of root extension were calculated from weekly measures of the deepest visible root in each column. Root extension rates ranged from ∼1.0 to 1.8 cm d−1 during the studies, with bahiagrass exhibiting the most rapid root extension of the four species. The results demonstrated that increasing N fertility during establishment increased rates of root extension into deep soil, particularly in bermudagrass. Height of cut had no effect on rate of root extension for most species, but higher cutting height did promote more rapid root extension in bermudagrass. Although not significantly accelerating vertical root extension in most species, maintaining sod at the higher cutting heights resulted in significantly greater root proliferation within both upper and lower soil depths for all species. The results emphasize the importance of proper N fertility and cutting heights for optimizing root development of different turfgrass species during sod establishment.}, number={6}, journal={AGRONOMY JOURNAL}, author={Wherley, B. G. and Sinclair, T. R. and Dukes, M. D. and Schreffler, A. K.}, year={2011}, pages={1629–1634} }
 @article{kemper_schneider_sinclair_2011, title={No-till can increase earthworm populations and rooting depths}, volume={66}, ISSN={["0022-4561"]}, DOI={10.2489/jswc.66.1.13a}, abstractNote={Crops grow by opening their stomata, which allow CO2 to enter their leaves, where CO2 and water can be photosynthesized into carbohydrates using the sun's energy. Photosynthesis occurs in the light only if CO2 continues to diffuse from the atmosphere into the interior of the leaves. However, stomata cannot remain open for CO2 diffusion if water is not continually supplied to the stomata to replenish the water these cells lose via transpiration. If the water flux from the soil is limited under drought conditions, stomata initiate closure and crop growth decreases. The soil profile is the critical storage reservoir, which can absorb and hold the rainfall until it is needed by the crop. The amount of rainfall that can be absorbed, stored, and made available for crop use depends on the porosity and texture of the soil and depth to which crop roots penetrate the soil. EFFECTS OF TILLAGE ON ABSORPTION AND RETENTION OF WATER AND CROP YIELDS One aspect of the absorption and holding capacity of soils that appears amenable to significant change by management is the runoff-infiltration tradeoff. Edwards and Norton (1986) found that with rainfall averaging about 100 cm y-1 (40 in yr-1) at…}, number={1}, journal={JOURNAL OF SOIL AND WATER CONSERVATION}, author={Kemper, W. Doral and Schneider, Nicholas N. and Sinclair, Thomas R.}, year={2011}, pages={13A–17A} }
 @article{cathey_kruse_sinclair_dukes_2011, title={Tolerance of three warm-season turfgrasses to increasing and prolonged soil water deficit}, volume={46}, number={11}, journal={HortScience}, author={Cathey, S. E. and Kruse, J. K. and Sinclair, T. R. and Dukes, M. D.}, year={2011}, pages={1550–1555} }
 @book{thomas r. sinclair_2010, title={Bread, beer, and the seeds of change agriculture's impact on world history}, DOI={10.1079/9781845937058.0000}, abstractNote={<title>Abstract</title> This book examines grain production and processing in various early agricultural societies as well as the technological advances in Western societies. The book is organized into three parts. The first part (chapters 2-6) examines background information and discusses the basics of cropping and food production that had to be resolved by all societies. Part II (chapters 7-11) is an examination of food production during the Golden Age of five ancient societies (the Sumerians, Egyptians, Chinese, Mayans, and the Bantu of Africa) that evolved more-or-less independently, each with unique agricultural practices. Topics discussed include the environmental conditions that existed to allow abundant crop production, the technology that was applied in growing the crops, and the methods used in baking and brewing during the Golden Age of each society. Part III (chapters 12-16) examines a succession of western societies which reflected a progression in increasing crop production technology. It considers the Golden Ages of five societies in this sequence: Athenian and Roman Empires, feudal Europeans, British, and Americans. An epilogue discusses the future of grain fermentation.}, publisher={Cambridge, MA: CAB}, author={Thomas R. Sinclair, Carol Janas Sinclair}, year={2010} }
 @article{gholipoor_prasad_mutava_sinclair_2010, title={Genetic variability of transpiration response to vapor pressure deficit among sorghum genotypes}, volume={119}, ISSN={["1872-6852"]}, DOI={10.1016/j.fcr.2010.06.018}, abstractNote={Simulation studies have demonstrated that limited maximum transpiration rate (TR) at high air vapor pressure deficit (VPD) in water-limited environments could result in significant increases in sorghum yield. However, such a restriction on TR at high VPD has not been documented in sorghum. The objective of this study was to search within sorghum germplasm for the possibility of restricted TR at high VPD. Twenty six genotypes were selected for measurement of VPD response based on field observations including yield, leaf temperature, and the stay-green phenotype. These genotypes were grown in a greenhouse for about 24-d growth, and then placed into individual chambers in which VPD was varied and TR measured. The results of this study showed marked variation among sorghum genotypes in TR response to VPD. Seventeen genotypes were identified as exhibiting a breakpoint in their VPD response in the range from 1.6 to 2.7 kPa, above which there was little or no further increase in TR. Therefore, these genotypes with a breakpoint have the possibility of soil water conservation when VPD during the midday cycle exceeds the breakpoint VPD. This trait would be desirable in less humid environments for increasing yields in water-deficit seasons. The observed range in the value of the BP among genotypes offers the possibility of developing genotypes with BP appropriate for specific environments.}, number={1}, journal={FIELD CROPS RESEARCH}, author={Gholipoor, Manoochehr and Prasad, P. V. Vara and Mutava, Raymond N. and Sinclair, Thomas R.}, year={2010}, month={Oct}, pages={85–90} }
 @article{sinclair_2009, title={Taking Measure of Biofuel Limits}, volume={97}, ISSN={["1545-2786"]}, DOI={10.1511/2009.80.1}, number={5}, journal={AMERICAN SCIENTIST}, author={Sinclair, Thomas R.}, year={2009}, pages={400–407} }