Analysis of Water Non-limiting and Water Limiting Yields and Yield Gaps of Groundnut in India Using CROPGRO-Peanut Model

To assess the scope for enhancing productivity of groundnut (Arachis hypogaea L.) in India, well‐calibrated and validated CROPGRO‐Peanut model was used to assess potential yields (water non‐limiting and water limiting) and yield gaps of groundnut for 18 locations representing major groundnut growing regions of India. The average simulated water non‐limiting pod yield of groundnut for the locations was 5440 kg ha^?1, whereas the water limiting yield was 2750 kg ha^?1 indicating a 49 % reduction in yield because of deficit soil moisture conditions. As against this, the actual pod yields of the locations averaged 1020 kg ha^?1, which was 4420 and 1730 kg ha^?1 less than the simulated water non‐limiting and water limiting yields, respectively. Across locations, the simulated water non‐limiting yields were less variable than water limited and actual yields, and strongly correlated with solar radiation during the crop season (R² = 0.62, P ≤ 0.01). Simulated water limiting yield showed a significant positive, but curvilinear relationship (R² = 0.73, P ≤ 0.01) with mean crop season rainfall across locations. The relationship between actual yield and the mean crop season rainfall across locations was not significant, whereas across seasons for some of the locations, the association was found to be significant. Total yield gap (water non‐limiting minus actual yields) ranged from 3100 to 5570 kg ha^?1, and remained more or less unaffected by the quantity of rainfall received across locations. The gap between simulated water non‐limiting and water limiting yields, which ranged from 710 to 5430 kg ha^?1, was large at locations with low crop season rainfall, and narrowed down at locations with increasing quantum of crop season rainfall. On the other hand, the gap between simulated water limiting yield and actual farmers yield ranged from 0 to 3150 kg ha^?1. It was narrow at locations with low crop season rainfall and increased considerably at locations with increasing amounts of rainfall indicating that type of interventions to abridge the yield gap will vary with the rainfall regimes. It is suggested that improved agronomic management (such as high yielding cultivars, balance crop nutrition and control of pest and diseases) in high rainfall regimes and rainfall conservation and supplemental irrigations in low rainfall regimes will be essential components of the improved technologies aimed at abridging the yield gaps of groundnut.     

棉花产量遥感预测的L-Y模型构建

本文利用LAI动态与棉花产量的关系建立了叶面积指数—产量（L-Y）模型,以期利用多时相遥感数据,实现对棉花产量定量遥感预测。模型建立以小区控制和大田生产试验数据为基础,以农学原理为背景,采用数学推演方法,具简单、灵活、普适性强等特点。检验结果表明,用便携式光谱辐射计测定棉花冠层高光谱反射率,以棉花全生育期LAI动态与棉花产量的关系和近地高光谱遥感参数模型监测的多时相LAI,可很好地定量预测棉花产量,估算误差约为5.44%,RMSE达到116.2 kg·hm^-2,预测值与实测值相关系数为0.836,达极显著水平。L-Y模型为棉花卫星遥感估产提供了参考模型,对其他作物使用动态生长信息提高遥感估产水平也有一定的借鉴意义。     

Deficit Irrigation of Soya Bean [Glycine max (L.) Merr.] in a Sub-humid Climate

An experiment was conducted to investigate the influence of different levels of water deficit on yield and crop water requirement of soya beans in a sub‐humid environment (Southern Marmara region, Bursa, Turkey) in 2005 and 2006. One full‐irrigated treatment (T₁), one non‐irrigated treatment (T₅) and three different deficit irrigation (T₂ = 25 % water deficit, T₃ = 50 % water deficit, T₄ = 75 % water deficit) treatments were applied to ‘Nova’ soya bean planted on a clay soil. Non‐irrigated and all deficit irrigation treatments significantly reduced biomass and seed yield and yield components. The full‐irrigated (T₁) treatment had the highest yield (3760 kg ha^?1), while the non‐irrigated (T₅) treatment had the lowest yield (2069 kg ha^?1), a 45.0 % seed yield reduction. T₂, T₃ and T₄ deficit irrigation treatments produced 11.7–27.4 % less seed yield than the T₁ treatment. Harvest index showed less and irregular variation among irrigation treatments. Both leaf area per plant and leaf area index were significantly reduced at all growth stages as amount of irrigation water was decreased. Evapotranspiration increased with increased amounts of irrigation water supplied. Our results indicate that higher amounts of irrigation resulted in higher seed yield, whereas water use efficiency and irrigation water use efficiency values decreased when irrigation amount increased.     

Tillage, cover crops, and nitrogen fertilization effects on soil nitrogen and cotton and sorghum yields

Sustainable soil and crop management practices that reduce soil erosion and nitrogen (N) leaching, conserve soil organic matter, and optimize cotton and sorghum yields still remain a challenge. We examined the influence of three tillage practices (no-till, strip till and chisel till), four cover crops {legume [hairy vetch (Vicia villosa Roth)], nonlegume [rye (Secaele cereale L.)], vetch/rye biculture and winter weeds or no cover crop}, and three N fertilization rates (0, 60–65 and 120–130 kg N ha⁻¹) on soil inorganic N content at the 0–30 cm depth and yields and N uptake of cotton (Gossypium hirsutum L.) and sorghum [Sorghum bicolor (L.) Moench]. A field experiment was conducted on Dothan sandy loam (fine-loamy, siliceous, thermic, Plinthic Paleudults) from 1999 to 2002 in Georgia, USA. Nitrogen supplied by cover crops was greater with vetch and vetch/rye biculture than with rye and weeds. Soil inorganic N at the 0–10 and 10–30 cm depths increased with increasing N rate and were greater with vetch than with rye and weeds in April 2000 and 2002. Inorganic N at 0–10 cm was also greater with vetch than with rye in no-till, greater with vetch/rye than with rye and weeds in strip till, and greater with vetch than with rye and weeds in chisel till. In 2000, cotton lint yield and N uptake were greater in no-till with rye or 60 kg N ha⁻¹ than in other treatments, but biomass (stems + leaves) yield and N uptake were greater with vetch and vetch/rye than with rye or weeds, and greater with 60 and 120 than with 0 kg N ha⁻¹. In 2001, sorghum grain yield, biomass yield, and N uptake were greater in strip till and chisel till than in no-till, and greater in vetch and vetch/rye with or without N than in rye and weeds with 0 or 65 kg N ha⁻¹. In 2002, cotton lint yield and N uptake were greater in chisel till, rye and weeds with 0 or 60 kg N ha⁻¹ than in other treatments, but biomass N uptake was greater in vetch/rye with 60 kg N ha⁻¹ than in rye and weeds with 0 or 60 kg N ha⁻¹. Increased N supplied by hairy vetch or 120–130 kg N ha⁻¹ increased soil N availability, sorghum grain yield, cotton and sorghum biomass yields, and N uptake but decreased cotton lint yield and lint N uptake compared with rye, weeds or 0 kg N ha⁻¹. Cotton and sorghum yields and N uptake can be optimized and potentials for soil erosion and N leaching can be reduced by using conservation tillage, such as no-till or strip till, with vetch/rye biculture cover crop and 60–65 kg N ha⁻¹. The results can be applied in regions where cover crops can be grown in the winter to reduce soil erosion and N leaching and where tillage intensity and N fertilization rates can be minimized to reduce the costs of energy requirement for tillage and N fertilization while optimizing crop production.     

Root Distribution of Drought-Resistant Peanut Genotypes in Response to Drought

The ability of a plant to modify its root distribution to exploit deeper stored soil water may be an important mechanism to avoid drought. This study aimed at assessing root distributions, variations in root length density (RLD) and percentage of root distribution, and the relevance of root traits for yield of drought‐resistant peanut genotypes under different available soil water levels. The experiment was conducted in the dry season during the years 2003/04 and 2004/05. Eleven peanut genotypes (ICGV 98300, ICGV 98303, ICGV 98305, ICGV 98308, ICGV 98324, ICGV 98330, ICGV 98348, ICGV 98353, Tainan 9, KK 60‐3 and Tifton‐8) and three soil moisture levels [field capacity (FC), 2/3 available soil water (AW) and 1/3 AW] were laid out in a split‐plot design with four replications. Roots were sampled by a core sampler at 37, 67 and 97 days after sowing (DAS). Root length was determined by a scanner and the WINRHIZO Pro 2004a software. RLD was calculated as the ratio of root length (cm) and soil volume (cm³). Graphical illustration of root distribution was constructed by merging RLD in the first and second soil layers (0–40 cm) as upper roots and pooling RLD at the third, fourth and fifth layers (40–100 cm) as lower roots. Pod yield, biomass and harvest index (HI) were recorded at harvest. A drought tolerance index (DTI) was calculated for each parameter as the ratio of the parameter under stress treatment to that under well‐watered conditions. Variations in RLD in 40 to 100 cm layer (RLD_{40 to 100 cm}) were found under well‐watered conditions, and the peanut genotypes could be readily identified as high, intermediate and low for this trait. Changes in RLD in the 40 to 100 cm soil layer were found at 2/3 AW and were more evident at 1/3 AW. ICGV 98300, ICGV 98303, ICGV 98305, ICGV 98308 and KK 60‐3 were classified as drought responsive as they increased RLD in the deeper subsoil level in response to drought. In general, RLD under drought conditions was not related to biomass production. The ability to maintain the percentage of RLD (DTI for %RLD) was related to pod yield, DTI for pod yield and DTI for HI. ICGV 98300, ICGV 98303, ICGV 98305 exhibited high DTI (RLD_{40 to 100 cm}) which may explain their high pod yield, DTI (PY) and DTI (HI). Based on these observations we classified them as drought‐avoiding genotypes.     

The Effect of Late-terminal Drought Stress on Yield Components of Four Barley Cultivars

Barley (Hordeum vulgare L.) is an important winter cereal crop grown in the semiarid Mediterranean, where late‐terminal drought stress during grain filling has recently become more common. The objectives of this study were to investigate the growth performance and grain yield of four barley cultivars under late‐terminal drought stress under both glasshouse and field conditions. At grain filling, four barley cultivars (Rum, ACSAD176, Athroh and Yarmouk) were exposed to three watering treatments: (1) well‐watered [soil maintained at 75 % field capacity (FC)], (2) mild drought stress at 50 % FC, (3) severe drought stress at 25 % FC in the glasshouse experiment and (1) well‐watered (irrigated once a week), (2) mild drought (irrigated once every 2 weeks), (3) severe drought (non‐irrigated; rainfed) in the field. As drought stress severity increased, gross photosynthetic rate, water potential, plant height, grain filling duration, spike number per plant, grain number per spike, 1000‐grain weight, straw yield, grain yield and harvest index decreased. In the glasshouse experiment, the six‐row barley cultivars (Rum, ACSAD176, and Athroh) had higher grain yield than the two‐row barley cultivar (Yarmouk), but the difference was not significant among the six‐row cultivars under all treatments. In the field experiment, Rum had the highest grain yield among all cultivars under the mild drought stress treatment. The two‐row cultivar (Yarmouk) had the lowest grain yield. In general, the traditional cultivar Rum had either similar or higher grain yield than the other three cultivars under all treatments. However, the yield response to drought differed between the cultivars. Those, Rum and ACSAD176, that were capable of maintaining a higher proportion of their spikes and grains per spike during drought also maintained a higher proportion of their yield compared with those in well‐watered treatment. In conclusion, cultivar differences in grain yield were related to spike number per plant and grain number per spike, but not days to heading or grain filling duration.     

Cropping System Affects Polymer‐Coated Urea Release and Corn Yield Response in Claypan Soils

Preplant‐applied, urea‐based fertilizer management in high‐residue, no‐till (NT) corn (Zea mays L.) is challenging because of potential N loss due to cool, wet conditions in the spring and dry conditions during the summer months. Field research evaluated the effects of polymer‐coated urea (PCU) application timing, placement and cropping system on urea release for corn and determined corn yield response to PCU on claypan soils following wheat (Triticum aestivum L.) cropping systems [reduced‐till corn following wheat, no‐till corn following wheat with double‐cropped (DC) soybean [Glycine max (L.) Merr.] and no‐till corn following wheat with a frost‐seeded red clover (FSC) (Trifolium pratense L.) cover crop]. Urea release from PCU was <35 % from fall through winter (November–January) and <20 % for early preplant (February–March) applications until 1 April. By 1 August, less urea was released in some instances from surface applications of PCU following FSC or DC soybean, but release was generally greater than in the absence of soil. No‐till corn following DC soybean or FSC had yields that were 1.01–1.32 Mg ha^?1 greater when grown with PCU compared to urea at 168 kg N ha^?1. Grain yields were similar within no‐till cropping systems with PCU, anhydrous ammonia and sidedressed urea ammonium nitrate (UAN) at 168 kg N ha^?1. Farmers should recognize that high yields may not be obtained if PCU rates are reduced by 50 % (84 kg N ha^?1) in high‐residue (DC soybean or FSC), no‐till production systems. Several N sources such as PCU, anhydrous ammonia and sidedressed UAN worked similarly in high‐residue, no‐till systems, although no differences between N sources were observed in a reduced‐tillage system.     

A maximin–minimax approach for classifying soybean genotypes for drought tolerance based on yield potential and loss

Screening for drought in soybean is often a bottleneck in plant breeding programmes. Sixteen genotypes were evaluated for drought tolerance during 2012, 2013 and 2014. The experiment was conducted in a split‐plot design, and the main plots consisted of irrigated and water stress treatments, and subplots consisted of 16 genotypes. The average seed yield was highest in 2012 (1708 kg/ha), followed by 2014 (1364 kg/ha) while very low yields (958 kg/ha) were observed during 2013. The per cent reduction in average soybean yield under water stress conditions was maximum (43%) during 2014 followed by 2012 (40%) and 2013 (31%), respectively. The average yields of soybean genotypes also differed significantly, which ranged from 892 (NRC 12) to 2008 kg/ha (JS 97‐52). The maximin–minimax approach was used to classify these genotypes, and only, one genotype was identified as drought resistant and high yielding (EC 538828), three as tolerant and high yielding (JS 97‐52, EC 456548 and EC 602288) and none as low yielding and resistant, while the remaining 12 genotypes were found to be low yielding and susceptible to drought.     

利用RZWQM-ERES模拟华北平原农田土壤水分动态及其对作物产量的影响

农业系统模型是农业生产多元目标优化管理的重要工具,但由于系统模型过程复杂,参数众多,校正和验证工作一直是模型研究的重点和难点。本文对RZWQM (Root Zone Water Quality Model)与CERES (Crop Environment Resource Synthesis)的结合模型RZWQM-CERES模拟土壤水分及作物产量进行了参数优化和验证,结果表明,RZWQM-CERES在禹城站和栾城站模拟不同灌溉处理土壤贮水量与测定值呈相似的变化趋势,均方根差(RMSE)分别为2.38~2.70 cm及3.49~3.73 cm;作物产量模拟结果与实测值对土壤水分的响应趋势一致(R² = 0.83^***,n = 22),其中在禹城站模拟小麦和玉米产量的RMSE分别为550 kg hm^-2和580 kg hm^-2,栾城站模拟小麦产量的RMSE为670 kg hm^-2。以上结果表明RZWQM-CERES可作为华北平原模拟和分析土壤水分对作物产量影响的有效工具。本文初步建立了一套适合华北平原作物生产的模型参数,为利用RZWQM-CERES建立农田水分优化调控策略奠定了基础,并探讨了模型评价过程中应注意的问题。     

Performance of landraces, exotic elite populations and their crosses in pearl millet (Pennisetum glaucum) in drought and non-drought conditions

The crop cultivars targeted for drought prone areas need to combine drought tolerance and high yield. The present study was conducted to assess the performance of three selected pearl millet landraces, four exotic elite populations and their 12 crosses. They were evaluated for yield, yield components and a drought susceptibility index that was calculated using yield data from drought and non‐drought environments. In the non‐drought season, the exotic populations had significantly higher grain yield than landraces. However, in the severe drought season, the landraces produced significantly greater biomass, grain and stover yields than elite populations. There was a strong relation between panicle size and ability to produce panicles and delay in flowering under severe stress. The biomass and stover yield of crosses was significantly better than parental populations under both drought stress and near‐optimum conditions. The elite populations were most sensitive to drought while crosses were as drought tolerant as landraces because they combined larger panicle size of exotics and lesser delay in flowering of landraces. The results indicated that it is possible to combine drought adaptation with high yield potential through hybridization between adapted landraces and elite genetic materials.     

花铃期干旱胁迫复水后棉花产量和纤维品质的变化研究

以抗旱差异明显的中棉所45(CCRI 45)和中棉所60(CCRI 60)为材料,采用人工控水的方法,研究棉花花铃期不同干旱胁迫程度和干旱胁迫后复水棉花根系干物质质量、皮棉产量和纤维品质的变化。结果表明,CCRI 45根系干物质质量增加幅度和皮棉产量在SRWC((45±5)%)干旱胁迫6 d后复水最大,且达到显著水平(P0.05),CCRI 60根系干物质质量增加幅度和皮棉产量在SRWC((60±5)%)干旱胁迫6 d后复水最大,且达到显著水平(P0.05),但CCRI 45和CCRI 60根系干物质质量和皮棉产量在SRWC((45±5)%)干旱胁迫9 d后复水显著低于对照。CCRI 45纤维上半部平均长度、整齐度指数、伸长率和断裂比强度在SRWC((60±5)%)和SRWC((45±5)%)干旱胁迫6 d后复水均高于对照,CCRI 60纤维上半部平均长度、整齐度指数、伸长率和断裂比强度在SRWC((45±5)%)干旱胁迫3 d和SRWC((60±5)%)干旱胁迫6 d后复水均高于对照,但未达到显著水平,CCRI 45和CCRI 60在SRWC((45±5)%)干旱胁迫9 d后复水纤维品质显著低于对照。在SRWC((45±5)%)干旱胁迫6 d后复水,CCRI 45根系干物质质量和皮棉产量的增加幅度大于CCRI 60,表明CCRI 45的抗旱性高于CCRI 60,且补偿能力较高。同时,棉花根系干物质质量增加量与棉花皮棉增加量存在显著的正相关关系。本研究结论将为棉花生产上适时、适度采取抗旱栽培调控措施及开展棉花节水高产栽培技术研究提供理论依据。     

利用RZWQM-ERES模拟华北平原农田土壤水分动态及其对作物产量的影响

农业系统模型是农业生产多元目标优化管理的重要工具,但由于系统模型过程复杂,参数众多,校正和验证工作一直是模型研究的重点和难点。本文对RZWQM (Root Zone Water Quality Model)与CERES (Crop Environment Resource Synthesis)的结合模型RZWQM-CERES模拟土壤水分及作物产量进行了参数优化和验证,结果表明,RZWQM-CERES在禹城站和栾城站模拟不同灌溉处理土壤贮水量与测定值呈相似的变化趋势,均方根差(RMSE)分别为2.38~2.70 cm及3.49~3.73 cm;作物产量模拟结果与实测值对土壤水分的响应趋势一致(R² = 0.83^***,n = 22),其中在禹城站模拟小麦和玉米产量的RMSE分别为550 kg hm^-2和580 kg hm^-2,栾城站模拟小麦产量的RMSE为670 kg hm^-2。以上结果表明RZWQM-CERES可作为华北平原模拟和分析土壤水分对作物产量影响的有效工具。本文初步建立了一套适合华北平原作物生产的模型参数,为利用RZWQM-CERES建立农田水分优化调控策略奠定了基础,并探讨了模型评价过程中应注意的问题。     

Potential impact of future climate change on sugarcane under dryland conditions in Mexico

Assessments of impacts of future climate change on widely grown sugarcane varieties can guide decision‐making and help ensure the economic stability of numerous rural households. This study assessed the potential impact of future climatic change on sugarcane grown under dryland conditions in Mexico and identified key climate factors influencing yield. The Agricultural Land Management Alternatives with Numerical Assessment Criteria (ALMANAC) model was used to simulate sugarcane growth and yield under current and future climate conditions. Management, soil and climate data from farm sites in Jalisco (Pacific Mexico) and San Luis Potosi (Northeastern Mexico) were used to simulate baseline yields. Baseline climate was developed with 30‐year historical data from weather stations close to the sites. Future climate for three decadal periods (2021–2050) was constructed by adding forecasted climate values from downscaled outputs of global circulation models to baseline values. Climate change impacts were assessed by comparing baseline yields with those in future decades under the A2 scenario. Results indicate positive impacts of future climate change on sugarcane yields in the two regions, with increases of 1%–13% (0.6–8.0 Mg/ha). As seen in the multiple correlation analysis, evapotranspiration explains 77% of the future sugarcane yield in the Pacific Region, while evapotranspiration and number of water and temperature stress days account for 97% of the future yield in the Northeastern Region. The midsummer drought (canicula) in the Pacific Region is expected to be more intense and will reduce above‐ground biomass by 5%–13% (0.5–1.7 Mg/ha) in July–August. Harvest may be advanced by 1–2 months in the two regions to achieve increases in yield and avoid early flowering that could cause sucrose loss of 0.49 Mg ha^?1 month^?1. Integrating the simulation of pest and diseases under climate change in crop modelling may help fine‐tune yield forecasting.     

Agronomic performance of winter wheat grown under highly divergent soil moisture conditions in rainfed and water‐managed environments

Even in the temperate climates of Europe, increasing early season drought and rising air temperature are presenting new challenges to farmers and wheat breeders. Sixteen winter wheat (Triticum aestivum L.) genotypes consisting of three hybrids, six line cultivars and two breeding lines from Germany as well as five line cultivars from France, Austria, Slovakia, Hungary and the Ukraine (referred to as “exotic” lines) have been included in this study. The genetic materials were evaluated over three growing seasons under a range of soil moisture regimes at the three North German sites Braunschweig (irrigated and drought‐stressed), Warmse (rainfed) and Söllingen (rainfed). The average grain yields in the twelve growth environments (water regime × season combinations) ranged from 6.1 to 13.5 t ha^?1. The exotic lines showed little evidence of specific phenological adaptation to drought although they are frequently faced with water scarcity in their countries of origin. The hybrids and German lines exhibited higher regression coefficients (b_i) to environmental means than the exotic lines, indicating particular adaptation to favourable growing conditions. The phenotypical correlations of grain yield between the various environments were high, ranging for instance from 0.6 to 0.8 for the irrigated and drought‐stressed environments at Braunschweig. It is thus expected that in the foreseeable future continued selection aiming at high yield potential will suffice as a means to counter the expected increase in droughts.     

Independent and combined effects of high temperature and drought stress around anthesis on wheat

High temperature and drought stress are projected to reduce crop yields and threaten food security. While effects of heat and drought on crop growth and yield have been studied separately, little is known about the combined effect of these stressors. We studied detrimental effects of high temperature, drought stress and combined heat and drought stress around anthesis on yield and its components for three wheat cultivars originating from Germany and Iran. We found that effects of combined heat and drought on the studied physiological and yield traits were considerably stronger than those of the individual stress factors alone, but the magnitude of the effects varied for specific growth‐ and yield‐related traits. Single grain weight was reduced under drought stress by 13%–27% and under combined heat and drought stress by 43%–83% but not by heat stress alone. Heat stress significantly decreased grain number by 14%–28%, grain yield by 16%–25% and straw yield by 15%–25%. Cultivar responses were similar for heat but different for drought and combined heat and drought treatments. We conclude that heat stress as imposed in this study is less detrimental than the effects of those other studied stresses on growth and yield traits.     

增温及干旱对海伦地区大豆生长发育的影响

研究旨在通过WOFOST模型探究不同程度的增温及干旱胁迫对黑龙江海伦地区大豆生长的影响,为当地大豆种植提供帮助。以海伦综合试验站的大豆生产数据为分析材料,用本地化处理后的WOFOST模型分别进行增温及干旱胁迫模拟,测得不同胁迫条件下大豆的生长数据。结果显示,在1℃~3℃的增温胁迫下大豆的生育期明显缩短,叶面积指数随着胁迫的增加不断减小,且产量随着温度的上升逐渐降低,增温3℃的情况下穗重产量下降11.01%,总重产量下降13.72%。在不同程度的干旱条件下,大豆的生育期长度没有明显的变化,但是叶面积指数有显著的下降,且产量受干旱的影响非常明显,其中重旱胁迫下穗部的减产率达13.26%。本研究从作物模型的角度分析了增温及干旱对海伦地区大豆的生长影响,对大豆防灾减灾、稳定增产具有重要意义。     

Improving adaptation to drought stress in white pea bean (Phaseolus vulgaris L.): Genotypic effects on grain yield,yield components and pod harvest index

Common bean (Phaseolus vulgaris L.) is the most important food legume crop in Africa and Latin America where rainfall pattern is unpredictable. The objectives were to identify better yielding common bean lines with good canning quality under drought, and to identify traits that could be used as selection criteria for evaluating drought‐tolerant genotypes. In all, 35 advanced lines were developed through single seed descent and evaluated with a standard check under drought and irrigated conditions at two locations over 2 years in Ethiopia. Grain yield (GY), pod number per m², seed number per m² and seed weight decreased by 56%, 47%, 49% and 14%, respectively, under drought stress. Eight genotypes had better yield with good canning quality under drought compared to the check. Moderate to high proportion of genetic effects were observed under drought conditions for GY and yield components compared to genotype × environment effects. Significant positive correlations between GY and pod harvest index (PHI) in drought suggest that PHI could be used as an indirect selection criterion for common bean improvement.     

Optimierung der Produktion von Wintergetreide zur Bioethanolherstellung durch unterschiedlich intensive Anbauverfahren

The investigations were based on biennial field trials carried out at two locations comprising the factors location/previous crop, winter cereal genotype (rye cv. ‘Farino’,triticale cv. ‘Modus’, wheat cv. ‘Batis’) and production intensity level. One agronomical focus was to replace the mineral N‐supply due to its energetic relevance, by either the residues of legumes, or stillage, a processing residue containing organic N. The measurement included the crop yield ha^?1, the bioethanol exploitation dt^?1 and the bioethanol yield ha^?1. The last was closely correlated to the grain yield and thus dominated by intensity level. Highest bioethanol yields with an average peak at 4022 l ha^?1, always occurred at the highest intensity level. Bioethanol exploitation however, was mainly determined by the genotype. The cultivars showed significant exploitation and yield differences. An adequate bioethanol exploitation was observed with the wheat cv. Batis in contrast to diminished grain and bioethanol yields. Considering bioethanol exploitation and bioethanol yield, the triticale cv. Modus was the outstanding genotype. Despite high grain yields, the bioethanol yields of the rye cv. Farino stayed mean, because of a genotypic lowered bioethanol exploitation. Comparing the approaches of mineral nitrogen substitution, legume N was successful, whereas stillage fertilizing, according to the examined conditions, resulted in ample decreased grain and bioethanol yields ha^?1.     

Applications of Foliar Fertilizers Containing Glycinebetaine Improve Wheat Yields

Nitrogen availability and drought influence wheat (Triticum aestivum L.) grain yields in the semiarid and subhumid Pampas region of Argentina. The application of fertilizers containing osmoprotectants, such as glycinebetaine, to crop canopies might reduce crop losses caused by environmental stresses. The objectives of this study were (a) to determine the effects on wheat grain yields of the foliar application of a commercial fertilizer with glycinebetaine, and (b) to establish, under farmers’ field conditions, the relation between soil properties and the productivity of wheat crops treated with the same product. Two experiments were conducted in the north‐western part of the Buenos Aires province of Argentina on Typic Hapludolls and Entic Hapludolls. In the first, the treatments were N fertilization (0, 23 and 46 kg ha^?1) and the foliar application to the wheat crop, in the vegetative stages, of a foliar fertilizer containing N, P, Zn and glycinebetaine (0 and 2.5 l ha^?1). The second experiment was carried out on 10 farmers’ fields, for each of which the treatment was the foliar application to the wheat crop, in the vegetative stages, of the same foliar fertilizer (0 and 2.5 l ha^?1). In both experiments, the grain yield, the individual grain weight, the number of grains per spike and the spike and plant density at the physiological maturity of the crops were determined. Soil organic matter (SOM) and available P were determined in each of the 10 fields of the second experiment. Wheat grain yields were increased by N fertilization and glycinebetaine treatment. The number of grains per spike was higher in the treatments with glycinebetaine application. In the farmers’ fields, the grain yields of the treatments with the application of the product with glycinebetaine were, on average, 18 % higher than those of the non‐treated plots, with greater responses at sites with low SOM levels. We conclude that, in subhumid regions with a dry period between the tillering and flowering stages of wheat, the foliar application of foliar fertilizers containing glycinebetaine at the vegetative stages of crop development enhances grain yields by increasing the number of grains per spike. This response is independent of the SOM level or the N fertilization rate.     

Drought Tolerance Screening Under Controlled Conditions Predicts Ranking of Water‐Limited Yield of Field‐Grown Soybean Genotypes

Drought is a major limitation to crop yields worldwide. Screening for soybean yield under water deficit is often a bottleneck in breeding programmes. We assessed the validity of a standardized drought tolerance screening method to predict water‐limited field performance of soybean in NW Argentina. First, to determine the phenological period when yield of glasshouse‐grown plants was more sensitive to water deficit, we applied treatments during 21 days in V₇, R₃ or R₅ stages, being the period from R₅ to R₆ the most critical for yield. Afterwards, two glasshouse experiments were carried out to quantify the tolerance of either eight or four genotypes, respectively, by applying a controlled water deficit of constant intensity during the critical period. Finally, yield data obtained in field trials in Argentina across several locations and seasons classified according to rainfall were analysed. Drought Susceptibility Index was calculated for each experiment and for field data, and rankings of tolerance were similar in all cases. This standardized method, which can be automated for high‐throughput phenotyping, could represent a useful tool in breeding programmes for identifying soybean cultivars with improved performance under drought conditions.