Drip irrigation and mulching were tested to minimize unproductive water loss through evaporation and weed interference. A field experiment was conducted during spring season of 2020 and 2021 in split plot design with three replications. The study includes six treatment combinations of drip irrigation methods (surface drip and subsurface drip irrigation) and mulching (black plastic, paddy straw and no mulch) along with one conventional furrow irrigation without mulching (as control) in main plots. Four weed control treatments (atrazine 1000 g a.i./ha as pre-emergence, two hand weedings at 30 and 60 days after sowing [DAS], weed free and weedy for whole crop growth period) were kept in the subplots. The combination of drip irrigation and mulches significantly enhanced leaf area index and crop biomass at 60 DAS than furrow irrigation. Integration of subsurface drip irrigation with plastic mulching resulted in the lowest weed density and biomass among main plots. Drip irrigation coupled with plastic and straw mulching resulted in 86 and 50% reduction in weed density and biomass, respectively, as compared to no mulching. Integration of subsurface drip with paddy straw mulch and black plastic mulch resulted in 17.1 and 15.5% higher maize grain yield, respectively, as compared to furrow irrigation. The highest irrigation water productivity (3.58 kg/m3) was observed in combination of subsurface drip and paddy straw mulch followed by combination of subsurface drip and black plastic mulch (3.51 kg/m3). Overall, straw mulching in drip irrigation system proved economical in terms of maize productivity.

Use of diverse germplasm for generating heterotic hybrids is the foremost requirement in maize. The present study was conducted by using a diverse set of inbred lines and the line × tester method was applied to identify best performing lines and to group QPM inbred lines into different heterotic groups. The test crosses, developed by following line (66) × tester (CML 161 and CML 165) mating design, were evaluated during winter 2013, rainy 2014 and 2015 seasons at Begusarai and Ludhiana, respectively. Based on the specific combining ability, the lines were categorized into two heterotic groups. Out of 66 novel inbreds, 18 lines with significant SCA with CML165 were classified in group A, 16 inbreds with significant SCA with CML161 were classified in group B and 20 inbreds with significant GCA were classified in group (AB). Nine inbred lines were selected based on their positive GCA values and pedigree crosses were developed in rainy season in 2017. Three crosses were made in heterotic group A and four crosses were in group B for synthesizing new inbred lines by using pedigree method. Heterotic grouping based inbred evaluation trial and biochemical analysis were carried out to estimate per se yield potential of developed lines and to estimate tryptophan content. QIL-4-2491 (Group-A) and QIL-4-2401 (Group-B) were the top yielders. A total of 25 crosses were made among the heterotic groups (A and B) by using 22 lines from groups A and B and three best performing hybrids were identified.

Understanding the yield attributes of rice crops grown at super high-yielding sites is useful for identifying how to achieve super high yield in rice. In this study, field experiments were conducted in 2021 and 2022 to compare grain yield and yield attributes of ten high-yielding hybrid rice varieties between Xingyi (a super high-yielding site) and Hengyang (a site with typical yields). Results showed that Xingyi produced an average grain yield of 13.4 t ha−1 in 2021 and 14.0 t ha−1 in 2022, which were, respectively, 20% and 44% higher than those at Hengyang. Higher panicles per m2 and higher grain weight were responsible for the higher grain yield at Xingyi compared to Hengyang. The higher values of panicles per m2 and grain weight at Xingyi compared to Hengyang were due to greater source capacity resulting from improved pre-heading biomass production. This study suggests that simultaneously increasing panicle number and grain weight through improving pre-heading biomass production is a potential way to achieve super high yield in rice.

Water deficit is one of the most important abiotic stresses constraining crop production in rapeseed. Understanding the mechanisms of adaptation to this stress is essential for the development and production of drought-tolerant genotypes. For this reason, this research study aims to investigate the importance of genetic diversity in identifying genotypes with a high degree of drought tolerance through assessing effectiveness of inter simple sequence repeat (ISSR) markers on 14 genotypes of rapeseed in a factorial design. Morphological and physiological characteristics were studied after the early stages of growth; in order to evaluate the genetic diversity among genotypes, 18 different ISSR markers were used. A total of 106 clear and scalable loci were amplified, of which 60 bands (56.6%) were polymorphic. The highest polymorphism information content belonged to marker number 9 with the amount of 0.365 (85.7%). Gene variation ranged from 0.081 to 0.365 and the rapeseed genotypes were divided into three groups by cluster analysis (unweighted pair group method with arithmetic mean method). The analysis of molecular variance showed that 70% of the total variation was observed within populations and 30% of this variation occurred among populations. In addition, t-test was used for comparing oil content percentage among different genotypes in control and stress levels. Adriana had the highest amount of seed oil with 36.47%, whereas Karaj 2 had the lowest amount with 27.28 and Cooper had the highest decrease in oil content percentage under stress conditions. Overall, the genotypes Likord, Hyola 401 and Sarigol 32 were identified as the most drought-tolerant.

Enhancing seedling quality and promoting root growth post-transplantation are crucial for improving mechanically transplanted rice productivity. Here we investigated the impact of various plant growth regulators on hybrid and conventional rice varieties. Treatments, including two-diethylaminoethyl hexanoate (DA-6, 10 mg L−1), a combination of potassium 3-indole-butyrate + potassium 1-naphthylacetate + 6-benzylaminopurine (C3, 50 + 50 + 10 mg L−1), potassium 3-indole-butyrate + potassium 1-naphthylacetate + 1-triacontanol (C4, 50 + 50 + 50 mg L−1), potassium 3-indole-butyrate + potassium 1-naphthylacetate + 1.8% sodium nitrophenolate (C5, 50 + 50 + 1 mg L−1), and a combination of potassium 3-indole-butyrate + potassium 1-naphthylacetate + 1.8% sodium nitrophenolate + DA-6 (C6, 50 + 50 + 1 + 10 mg L−1), were sprayed either 3 or 10 days before transplanting. Seedlings sprayed 10 days before transplanting exhibited a higher number of white roots and total roots at the returning green stage, along with increased grain yield, irrespective of the plant growth regulator used. The C6 combination emerged as the most effective treatment, enhancing the growth of both hybrid and conventional rice seedlings, accelerating the growth rate of white roots and total roots, and increasing the length of the longest white root during the greening period, ultimately resulting in higher grain yield. Our findings demonstrate that pre-transplantation application of a combination of plant growth regulators positively influences rice seedling growth.

Cover crop residue retention on the soil surface can suppress weeds and improve organic no-till soybean (Glycine max) yield and profitability compared to a tilled system. Appropriate cereal rye (Secale cereale) fall planting date and termination methods in the spring are critical to achieve these benefits. A plot-scale agronomic experiment was carried out from September 2018 to October 2021 in Kutztown, PA, USA to demonstrate the influence of cereal rye planting date (September or October) and mechanical termination method [no-till (I & J roller-crimper, Dawn ZRX roller, and mow-ted) and tilled (plow-cultivate)] on cover crop regrowth density, weed biomass, soybean yield, and economic returns. In one out of three years, the September rye planting accumulated more cover crop biomass than the October planting, but the regrowth of the rye after roller-crimping was greater with this planting date. Cover crop planting date had no effect on total weed biomass and demonstrated varying effects on soybean grain yield and economic returns. The Dawn ZRX roller outperformed the I & J roller-crimper in effectively terminating cover crops, while the I & J roller-crimper demonstrated more uniform weed suppression and led to greater soybean yields over a span of three years. Organic no-till strategies eliminated the need for tillage and reduced variable costs by 14% over plow-cultivated plots, and generated ~19% greater net revenue across the study period (no-till vs tillage = US $845 vs US $711 ha−1). Terminating cereal rye with roller-crimping technology can be a positive investment in an organic soybean production system.

Fallow weeds can be abundant in rice paddies without any inputs and provide ecosystem services like those of cover crops, such as reducing nitrogen (N) leaching and capturing carbon. Therefore, allowing fallow weeds to grow is a potential alternative to cover crops in rice cropping systems. To evaluate the feasibility of this strategy, the effect of fallow weeds on grain yield in rice needs to be clarified. In this study, 2-year field experiments were conducted to compare N uptake, biomass production, yield components, and grain yield in rice with and without application of fallow weeds (500 g m−2, sun-dried). Results showed that the application of fallow weeds reduced aboveground N uptake and biomass production by 21–30% during the early growth period (from transplanting to mid-tillering) in rice. However, these reductions did not lead to reduced grain yield because they were compensated for or even exceeded by increased aboveground N uptake and biomass production during the middle and late growth periods (from panicle initiation to maturity). In addition, the application of fallow weeds increased spikelets per panicle in rice by 6–7%. These results provide preliminary evidence that fallow weeds may alter yield formation in rice and highlight the need for further investigations of the ecophysiological mechanism underlying the effect of fallow weeds on N uptake in rice.

In common with other grain legumes, the growth habit in horse gram is one of the domestication-driven adaptive traits. Horse gram exhibits determinate and indeterminate types of growth habits. Determinate genotypes have non-overlapping vegetative and reproductive phases combined with a compact growth habit which enables farmers to produce horse gram in intercropping and multiple cropping systems, a common practice for sustainable agriculture production. Also, synchronous flowering, and pod development and maturity of determinate genotypes enable mechanical harvesting. Empirical studies have indicated a greater grain yield potential of indeterminate compared to determinate genotypes. However, we hypothesize that indeterminate and determinate genotypes do not differ for their grain yield potential if they are in isogenic genetic backgrounds. To test this hypothesis, we compared eight pairs of near isogenic (NI) indeterminate and determinate genotypes for their grain yield potential during two rainy seasons in one location and one rainy season in another location. The eight pairs of NI determinate and indeterminate genotypes differed significantly in each of the three test environments. Indeterminate genotypes produced a greater pod (harvestable) and grain (marketable) yields than their determinate counterparts only in a few genetic backgrounds. These results thus support our hypothesis that determinate genotypes are comparable to indeterminate ones, if not better than the latter.

The development of glufosinate-resistant soybean cultivars has created opportunities for use of glufosinate applied postemergence for weed control. Four field experiments were conducted in 2021 and 2022 to ascertain the effect of glufosinate rate and the addition of ammonium sulfate on annual weed control in glyphosate/glufosinate/2,4-D–resistant soybean. An increased glufosinate rate of 500 from 300 g ai ha−1 improved control of common ragweed, common lambsquarters, redroot pigweed, and foxtail species and resulted in decreased density and dry biomass of common lambsquarters and foxtail species. The addition of ammonium sulfate to glufosinate increased control of common lambsquarters, 2 and 8 wk after application (WAA), and of foxtail species, 2, 4, and 8 WAA, but did not improve control of common ragweed and redroot pigweed. Increasing the dose of glufosinate from 300 to 500 g ai ha−1 improves control of common ragweed, redroot pigweed, common lambsquarters, and foxtail species; however, the benefit of the addition of ammonium sulfate to glufosinate is weed species-specific.

Screening of germplasm for specific traits is a continuous pre-breeding process in deriving the drought-tolerant donors required for crop improvement. The study evaluated 17 medium-late duration finger millet genotypes under drought stress (DS) for 28 days during the reproductive stage to identify the traits and genotypes for drought tolerance using different statistical analysis. The photosynthetic rate (by 26.3%), stomatal conductance (by 26.4%), transpiration rate (by 24.8%) and grain yield (by 13.2%) were decreased and found sensitive to DS, but the leaf temperature was increased (4.7%). From the path analysis and multiple linear regression analysis, the mean ear weight and productive tillers were found to contribute to the grain yield significantly under well-watered conditions. While under DS conditions, the mean ear weight, productive tillers and threshing percentage equally contributed to grain yield. Based on the ranking of traits significantly contributing to grain yield, the genotype GE-4683 with a higher mean ear weight (10.65 g) was found superior to the popular variety, GPU-28. The Multiple linear regression equation predicts the possibility to increase the yield of GPU-28 under DS from the existing 360.0 to 459.5 g per square metre (by 29.1%) by the incorporation of three productive tillers instead of the existing two tillers per plant in the MLR equation. An additional 1.0 g of mean ear weight will be able to predict an increased grain yield from 360.0 to 392.0 gm−2, equivalent to 3.60 to 3.92 t/ha (by 9.4%).

We investigated whether the one-time application of polymer-coated urea (PCU) before transplanting could simultaneously improve the grain yield and nitrogen use efficiency (NUE) of japonica-indica hybrid rice (JIHR) through a field experiment. The local high-yield JIHR cultivar Chunyou-927 was field grown during the rice-growing seasons in 2019 and 2020. The experiment consisted of three treatments: no nitrogen application (0N), application of conventional urea (CU), and the one-time application of PCU. Grain yield was 1.0–1.3 t/ha higher, and agronomic NUE (kg grain yield increase per kg N applied) was 5.2–5.9 kg/kg higher, respectively, under the PCU treatment compared with the CU treatment across the two study years. When compared with the CU treatment, the PCU treatment could (1) improve root morphological trait, (2) reduce redundant vegetative growth during the early growth period, (3) increase matter production during the mid and late growth period, and (4) increase plant activity during the grain-filling period. Overall, our findings indicate that one-time PCU application before transplanting of the JIHR cultivar holds great promise for increasing grain yield and NUE.

The genotype × environment (GE) interaction analysis is fundamental in crop breeding programs to guide selection and for recommendation of high performing and stable genotypes for breeding objectives. This study aimed at quantifying the GE interaction effects and determines grain yield stability among winter bread wheat genotypes under rainfed conditions of Iran. Twenty-four winter wheat genotypes were evaluated under nine test locations using a randomized complete blocks design with four replications during three cropping seasons (2019–21). The additive main effects and multiplicative interaction (AMMI) model and several parametric and nonparametric stability statistics were applied for analysis of grain yield data collected from the experiments. AMMI analysis of variance for grain yield revealed significant effects (p < 0.01) for genotype, environment, and GE interaction. The environment was the main source of variation and accounted for 83.5% of the total yield variation, followed by GE (6.5%) and genotype (1.0%) effects. The AMMI biplot analysis indicated the genotypes G3, G23, G22, G10, and G19 as high yielding with stability performance across environments. Genotypes G14, G13, G20, and G9 showed large positive interaction with the environments featuring the highest rainfall during growing season, while genotypes G7, G6, and G21 had a large positive interaction with environments with low rainfall. Spearman’s rank correlation analysis revealed that the AMMI stability value, Shukla’s stability variance (σ2i), Wricke’s ecovalence (W2i), coefficient of determination (R2i), variance in regression deviations (S2di), and nonparametric statistic of S2(i) were not correlated with mean yield in tested genotypes, showing they are related to static/biological concept of stability. In contrast, the genotypic superiority index (Pi) and regression coefficient (bi) were significantly correlated (p < 0.01) with mean yield and corresponded to dynamic/agronomic concept of stability. These findings suggest that selection of genotypes should be considered based on selection objectives of using the various stability parameters described here. In conclusion, the selected genotypes in this study should be recommended as new cultivars or parental lines for grain yield and stability improvement under rainfed conditions of Iran or similar agro-ecologies.

Dual-purpose sorghum response to anthracnose disease, growth, and yield was undertaken in Derashe and Arba Minch trial sites during March–June 2018 and 2019. Five sorghum varieties and Rara (local check) were arranged in a randomized complete block design with four replications. Variety Chelenko exhibited the tallest main crop plant height (430 cm) while Dishkara was the tallest (196.65 cm) at ratoon crop harvesting. Rara had a higher tiller number (main = 6.73, ratoon = 9.73) among the varieties. Dishkara and Chelenko varieties produced 50 and 10% more dry biomass yield (DBY) than the overall mean DBY, while Konoda produced 40% less. Although the anthracnose infestation was highest on the varieties Konoda (percentage severity index [PSI] = 20.37%) and NTJ_2 (PSI = 32.19%), they produced significantly (p < .001) higher grain yield (3.89 t/ha) than others. Under anthracnose pressure, Chelenko and Dishkara varieties are suggested for dry matter yield while NTJ_2 for grain yield production in the study area and similar agroecology.

Little information is available on the relative efficacy of Group 4 herbicides for glyphosate-resistant (GR) horseweed management in soybean. Five field research experiments were conducted in growers’ fields from 2020 to 2021 to determine GR horseweed control with Group 4 herbicides applied preplant (PP) alone and in a mixture. There was minimal soybean injury (≤4%) with herbicides evaluated. Dicamba, 2,4-D, or halauxifen-methyl applied PP controlled GR horseweed 92% to 96%, 73% to 76%, and 85% to 89%, respectively. The mixtures of dicamba + 2,4-D, dicamba + halauxifen-methyl and dicamba + 2,4-D + halauxifen-methyl provided 97% to 99% control of GR horseweed, similar to dicamba applied alone. The mixture of 2,4-D + halauxifen-methyl provided 93% to 94% control of GR horseweed. Dicamba + saflufenacil controlled GR horseweed at 98%. Dicamba alone, dicamba + 2,4-D ester, dicamba + halauxifen-methyl, and dicamba + 2,4-D ester + halauxifen-methyl decreased GR horseweed density 97%, 99%, 99%, and 98%, respectively, similar to a 98% density reduction with dicamba + saflufenacil. Other herbicide treatments had no effect on GR horseweed density. Dicamba, 2,4-D, and halauxifen-methyl applied PP decreased GR horseweed dry biomass by 99%, 76%, and 72%, respectively. The mixtures of dicamba + 2,4-D, dicamba + halauxifen-methyl, and dicamba + 2,4-D + halauxifen-methyl decreased GR horseweed dry biomass by 99% to 100%, similar to a 99% dry biomass reduction with dicamba + saflufenacil. The mixture of 2,4-D + halauxifen-methyl decreased GR horseweed dry biomass by 94%. Soybean yield was decreased by 61% when GR horseweed was left uncontrolled. Results show that Group 4 herbicides that include dicamba applied PP can be very effective in managing GR horseweed in soybean.

Intercropping maize (Zea mays L.) with cover crops (Crotalaria spectabilis and Urochloa ruziziensis) is a sustainable cultivation strategy that can generate ecological benefits combined with grain yield (GY). However, cover crops may require nitrogen (N) fertilization management to be adjusted to obtain a high GY in intercropping systems. This study was carried out over 2 years in southeastern Brazil using randomized complete block design in a split-plot scheme. The plots were composed of three cropping systems: sole maize, maize + U. ruziziensis and maize + C. spectabilis. The subplots consisted of four N levels: 0, 70, 140 and 210 kg/ha. The GY of the maize + U. ruziziensis may be reduced by 13% compared to the sole maize. The GY of the sole maize increased up to 11.3 Mg/ha for 95 kg/ha of N in the first year and 6.7 Mg/ha for 169 kg/ha of N in the second year. The GY of the maize + U. ruziziensis intercropping system showed linear increments of 120 kg/ha for every 10 kg/ha of N applied. In the maize + C. spectabilis intercropping, GY increased up to 9.8 Mg/ha for 201 kg/ha of N in the first year, without any variation during the second year. The land equivalent ratio (LER) of intercropping was increased by more than 35% compared to that of sole maize, and N fertilization increased the LER of the sole maize and maize + U. ruziziensis intercropping. Maize intercropping had higher LER values with greater demand for nitrogen to obtain similar yields compared to sole maize cropping.

Improving grain yield and lodging resistance are two important targets for improving rice production. The aim of this study was to link grain yield and lodging resistance with growth patterns in rice. A nitrogen (N) fertilization experiment was conducted in 2020 and 2021, which consisted of two N rates (150 and 225 kg ha–1) and three N split-application ratios among the basal, early tillering, and panicle initiation stages (6:3:1, 5:3:2, and 4:3:3). The results demonstrated that increasing the N rate from 150 to 225 kg ha–1 did not affect grain yield but increased the plant lodging index by 16%. This increase in the plant lodging index was attributable to a higher plant fresh weight resulting from improved post-heading growth and a lower plant lodging load, which was partially due to a higher leaf area index. Altering the N split-application ratio from 6:3:1 to 4:3:3 increased grain yield by 4% but did not affect the plant lodging index in rice. The increase in grain yield was due to improved post-heading growth mainly resulting from increased radiation use efficiency during the post-heading period, which was partially attributable to increased specific leaf weight. An improvement in pre-heading growth in 2021 did not affect grain yield but increased the plant lodging load and decreased the plant lodging index by 36% compared to 2020. The improvement in pre-heading growth was due to a higher intercepted solar radiation resulting from higher leaf area index and incident solar radiation during the pre-heading period. The results of this study indicate that improving pre-heading growth can maintain grain yield and increase lodging resistance, while improving post-heading growth by increasing canopy radiation use efficiency (but not the leaf area index) can increase grain yield and maintain lodging resistance.

Glyphosate-resistant (GR) horseweed interference in soybean can reduce soybean yield up to 93%. Glyphosate plus dicamba, 2,4-D ester, halauxifen-methyl or pyraflufen-ethyl/2,4-D applied preplant (PP) provide variable GR horseweed control in soybean. The objective of this study was to determine if the addition of saflufenacil or metribuzin to glyphosate plus dicamba, 2,4-D ester, halauxifen-methyl, or pyraflufen-ethyl/2,4-D will improve the level and consistency of GR horseweed control. Four trials were conducted over the 2020 and 2021 field seasons in fields with GR horseweed populations. Glyphosate plus dicamba, 2,4-D ester, halauxifen-methyl, or pyraflufen-ethyl/2,4-D controlled GR horseweed 96%, 77%, 71%, and 52%, respectively, at 8 wk after application (WAA). When saflufenacil or metribuzin was added to glyphosate plus dicamba or 2,4-D ester, GR horseweed control was not improved at 8 WAA. When saflufenacil or metribuzin was added to glyphosate plus halauxifen-methyl, GR horseweed control improved by 27% and 25%, respectively, at 8 WAA. When saflufenacil or metribuzin was added to glyphosate plus pyraflufen-ethyl/2,4-D, GR horseweed control was improved by 47% and 37%, respectively, at 8 WAA. The consistency of GR horseweed control was improved when saflufenacil or metribuzin was added to glyphosate plus dicamba, 2,4-D ester, halauxifen-methyl, or pyraflufen-ethyl/2,4-D compared to each herbicide applied alone. Synergism was observed when metribuzin was added to glyphosate plus halauxifen-methyl and when saflufenacil or metribuzin was added to glyphosate plus pyraflufen-ethyl/2,4-D at 8 WAA. Though GR horseweed control was improved with the addition of saflufenacil or metribuzin to glyphosate plus halauxifen-methyl or pyraflufen-ethyl/2,4-D, all treatments including saflufenacil resulted in the highest level and most consistent control.

Six field experiments were conducted to investigate any interaction between pyroxasulfone and flumioxazin on soybean tolerance and control of multiple-herbicide-resistant (MHR) waterhemp in soybean during 2016 and 2017 in Ontario, Canada. There was a synergistic increase in soybean injury with the co-application of pyroxasulfone and flumioxazin at all rates evaluated at 2 wk after emergence (WAE), the two highest rates evaluated (134/106 and 268/211 g ai ha–1) at 4 WAE, and the highest rate (268/211 g ai ha–1) evaluated at 8 WAE. Soybean injury with all pyroxasulfone and flumioxazin treatments was transient and had no adverse effect on soybean grain yield. Pyroxasulfone applied preemergence at 45, 89, 134, and 268 g ai ha–1 controlled MHR waterhemp up to 72%, 89%, 92%, and 95%, respectively. Flumioxazin applied preemergence at 35, 70, 106, and 211 g ai ha–1 controlled MHR waterhemp up to 78%, 90%, 93%, and 96%, respectively. Pyroxasulfone/flumioxazin applied preemergence at 45/35, 89/70, 134/106, and 268/211 g ai ha–1 controlled MHR waterhemp up to 92%, 96%, 98%, and 100%, respectively. There were no significant antagonistic or synergistic interactions for the control of MHR waterhemp with pyroxasulfone/flumioxazin at rates evaluated except at 268/211 g ai ha–1, which provided a synergistic increase in MHR waterhemp control at 4 WAE. The MHR waterhemp biomass and density reductions followed a trend similar trend to visible control. Pyroxasulfone/flumioxazin at 268/211 g ai ha–1 caused a synergistic response in biomass reduction (9% difference). Based on these results, there is an additive increase in MHR waterhemp control and potential for a synergistic increase in soybean injury with the co-application of pyroxasulfone plus flumioxazin.

The flag leaf acts as a functional leaf in rice, Oryza sativa L., primarily supplying photosynthate to the developing grains and influencing yields to a certain extent. Drought stress damages the leaf physiology, severely affecting grain fertility. Autumn rice of northeast India is called locally as ‘ahu’ rice, and is known for its drought tolerance. Exploring diverse germplasm resources at the morphological level using an association mapping approach can aid in identifying the genomic regions influencing leaf shape dynamics. A marker–trait association (MTA) study was carried out using 95 polymorphic SSR markers and a panel of 273 ahu rice germplasm accessions in drought stress and irrigated conditions. The trials suggest that at the vegetative stage, drought stress significantly affects leaf morphology. The leaf physiology of some tolerant accessions was relatively little affected by stress and these can be considered as ideal varieties for drought conditions. The phenotypic coefficient of variance and genotypic coefficient of variance values implied moderate to high variability for the leaf traits studied. Analysis of molecular variance inferred that 11% of variation in the germplasm panel was due to differences between populations, while the remaining 89% may be attributed to a difference within subgroups formed through STRUCTURE analysis. Using the mixed linear model approach revealed 11 MTAs explaining between 4.5 and 20.0% of phenotypic variance at P > 0.001 for all the leaf traits. The study concludes that ahu rice germplasm is extremely diverse and can serve as a valuable resource for mining desirable alleles for drought tolerance.