Differences In Grain Yield Research Articles

Effect of sowing methods, spacings, and fertilizer levels on quantitative and qualitative traits and economics of brown top millet (Brachiaria ramosa L.) under different cropping seasons

A field study was conducted during the Summer, Kharif, and Rabi seasons of 2023-2024 to evaluate brown top millet under two sowing methods (direct sowing and transplantation), three spacing configurations (20 x 10, 30 x 10 and 45 x 10 cm), and three fertilizer doses (75% of the recommended dose of fertilizer (RDF) (45:20:15 kg ha-1), 100% RDF (60:30:20 kg ha-1), and 125% RDF (75:40:25 kg ha-1)). The study was designed as a factorial randomized complete block design assessing growth, yield, thiamine content, and economics. The results indicated that the summer season was more favorable for growth than the Kharif and Rabi seasons. Direct sown crops (E1) exhibited significantly higher growth attributes, yield, and economics than transplanted crops (E2). The spacing configuration of 45 x 10 cm (S3) recorded significantly superior growth and yield parameters compared to 20 x 10 cm (S1). Applying 125% RDF (N3) resulted in significantly enhanced growth, yield, quality, and economic return compared to 75% RDF. Among the interactions, the combination of direct sown with narrow spacing and 125% RDF (E1 x S1 x N3) led to significantly higher growth parameters. In comparison, the combination of direct sowing with wider spacing and 125% RDF (E1 x S3 x N3) resulted in higher grain yields (2005, 1759, 1548 kg ha-1) and benefit-cost ratios (2.64, 2.58, and 2.58) across the same seasons. However, the differences in grain yield among the treatment combinations were statistically non-significant. These findings provide a valuable foundation for future research and agricultural practices aimed at maximizing the potential of brown top millet.

Differences in Grain Yield and Nitrogen Uptake between Tetraploid and Diploid Rice: The Physiological Mechanisms under Field Conditions.

Research indicates that, owing to the enhanced grain-filling rate of tetraploid rice, its yield has notably improved compared to previous levels. Studies conducted on diploid rice have revealed that optimal planting density and fertilization rates play crucial roles in regulating rice yield. In this study, we investigated the effects of different nitrogen application and planting density treatments on the growth, development, yield, and nitrogen utilization in tetraploid (represented by T7, an indica-japonica conventional allotetraploid rice) and diploid rice (Fengliangyou-4, represented by FLY4, a two-line super hybrid rice used as a reference variety for the approval of super rice with a good grain yield performance). The results indicated that the highest grain-filling rate of T7 could reach 77.8% under field experimental conditions due to advancements in tetraploid rice breeding. This is a significant improvement compared with the rate seen in previous research. Under the same conditions, T7 exhibited a significantly lower grain yield than FLY4, which could be attributed to its lower grain-filling rate, spikelets per panicle, panicle number m-2, and harvest index score. Nitrogen application and planting density displayed little effect on the grain yield of both genotypes. A higher planting density significantly enhanced the leaf area index and biomass accumulation, but decreased the harvest index score. Compared with T7, FLY4 exhibited a significantly higher nitrogen use efficiency (NUEg), which was mainly due to the higher nitrogen content in the straw. Increasing nitrogen application significantly decreased NUEg due to its minimal effect on grain yield combined with its significant enhancement of nitrogen uptake. Our results suggest that the yield and grain-filling rate of T7 have been improved compared with those of previously tested polyploid rice, but are still lower than those of FLY4, and the yield of tetraploid rice can be further improved by enhancing the grain-filling rate, panicle number m-2, and spikelets per panicle via genotype improvement.

THE PERFORMANCE OF SEVEN ELITE MAIZE ACCESSIONS FROM DIFFERENT AFRICAN ORIGINS UNDER RAIN-FED CONDITIONS IN SOUTH-EASTERN NIGERIA

Maize is an important cereal crop, and millions of Africans rely on it as a major source of carbohydrates in their diet. Grain yield from local maize varieties is generally low. Evaluation of different maize genotypes within a specific region is one way to identify and introduce varieties with high yield potential. This study assessed the yield and agronomic traits of 6 exotic maize accessions and a local variety to compare the performance of the exotic accessions with the local variety. The experiment was laid out as a randomized complete block design with four replications. The treatments included six exotic maize accessions, TZM386, TZM85, TZM16, TZM109, TZM392, and TZM1330, and a local variety ‘Uwep’ the result indicated that there were no significant differences in plant height and plant population at anthesis. Grain yiel among all accessions was not greater than 0.5 t/ha in 2020 but ranged between 1-3 t/ha in 2021. There were no significant differences in grain yield and components between the exotic and local accessions in 2021. In 2020, TZM 386 outperformed the local variety (uwep) in grain yield, ear weight, and number of ears/ha. Multiple linear regression showed a high dependence of grain yield on the growth parameter-plant height and the yield component ear no/ha in 2020 and 2021. This study has revealed differences in yield traits between the local and exotic accessions. The maize accession TZM 386 showed potential for higher grain yield and yield components and appears to be a promising candidate for further research.

Synergistic effects of microbial inoculation, different forms of iron application, and phosphorus on wheat growth and nutrient uptake in alkaline soil

Iron and phosphorus deficiencies in alkaline soils threaten wheat by limiting nutrient availability due to their antagonistic relationship. This study tested if combining microbial incubation with foliar iron could synergistically improve wheat productivity and nutrition and mitigate deficiencies. A field experiment using a split plot design tested different iron and phosphate fertilization techniques. The main plots consisted of three iron application methods: foliar-applied iron (FL) at 2.5 kg ha−1, soil-applied iron (FS) at 5 kg ha−1, and no iron (F0). The subplots comprised four phosphate fertilizers: PSB + TSP (inoculation with phosphate-solubilizing bacteria + 100 kg ha−1 of triple superphosphate fertilizer), AMF + TSP (inoculation with arbuscular mycorrhizal fungi + triple superphosphate), TSP alone, and no phosphorus (P0). Foliar iron application with AMF + TSP increased seed potassium and root length density by 16.3-17.9% and 22.1-25.8% more than PSB + TSP, respectively. Under FS conditions, AMF + TSP exhibited 28.5-29.1% lower magnesium and 23.9-28.4% higher zinc seed concentrations compared to PSB + TSP, as well as higher levels of soluble proteins and lower concentrations of chlorophyll. There was no difference in grain yield between PSB + TSP and AMF + TSP for any of the iron treatments. Combining AMF + TSP and foliar iron application resulted in the highest grain yield, desirable seed nutrient content (particularly zinc, iron (>100 mg kg−1), and magnesium (>18 mg kg−1), improved root biomass, chlorophyll, and soluble proteins compared to PSB + TSP and TSP alone. This combination of microbial inoculation with foliar iron application is an effective strategy for mitigating the antagonism between iron and phosphorus and improving both crop productivity and nutrition.

The Impact of Planting Technology on the Maize Yield

The three–year trials of the impact of the planting technology on the maize yield were carried out at the trial sites Jakšić and Tenja. The KWS Intelligens and KWS Kollegas hybrids were used in the research, planted at a standard row spacing of 70 cm, and in the twin rows with a spacing of 48 × 22 cm. In 2020, the highest average grain yield at the site Jakšić in standard planting, with the KWS Intelligens hybrid, was 12.064 t ha–1, and in the twin row planting an increase in yield of +4.17% was recorded. The KWS Kollegas hybrid had the highest difference in grain yield between a standard and twin row planting in 2021 of +7.52%, in favor of the twin row. At the site Tenja, slightly higher grain yields were recorded in all three years of research. The major difference in yield was recorded in 2020 with the hybrid KWS Kollegas, of +8.22%, or 1.115 t more grain, when planting in the twin rows in comparison with a standard planting. The statistical tests indicate that planting in the twin rows at both trial sites obtained statistically significant results in all three years of research concerning the grain yield ha–1, grain weight per ear, and grain moisture content.

High-density mapping of durable and broad-spectrum stripe rust resistance gene Yr30 in wheat.

The durable stripe rust resistance gene Yr30 was fine-mapped to a 610-kb region in which five candidate genes were identified by expression analysis and sequence polymorphisms. The emergence of genetically diverse and more aggressive races of Puccinia striiformis f. sp. tritici (Pst) in the past twenty years has resulted in global stripe rust outbreaks and the rapid breakdown of resistance genes. Yr30 is an adult plant resistance (APR) gene with broad-spectrum effectiveness and its durability. Here, we fine-mapped the YR30 locus to a 0.52-cM interval using 1629 individuals derived from residual heterozygous F5:6 plants in a Yaco"S"/Mingxian169 recombinant inbred line population. This interval corresponded to a 610-kb region in the International Wheat Genome Sequencing Consortium (IWGSC) RefSeq version 2.1 on chromosome arm 3BS harboring 30 high-confidence genes. Five genes were identified as candidate genes based on functional annotation, expression analysis by RNA-seq and sequence polymorphisms between cultivars with and without Yr30 based on resequencing. Haplotype analysis of the target region identified six haplotypes (YR30_h1-YR30_h6) in a panel of 1215 wheat accessions based on the 660K feature genotyping array. Lines with YR30_h6 displayed more resistance to stripe rust than the other five haplotypes. Near-isogenic lines (NILs) with Yr30 showed a 32.94% higher grain yield than susceptible counterparts when grown in a stripe rust nursery, whereas there was no difference in grain yield under rust-free conditions. These results lay a foundation for map-based cloning Yr30.

Farmers participatory evaluation of bread wheat varieties through seed producer cooperatives: evidence from Ethiopia

The limited engagement of farmers and their community agents in the process of variety development and evaluation is one of the main factors for lower rates of variety adoption, which resulted in lower crop productivity. Participatory bread wheat variety evaluation was jointly conducted by breeders, members of seed producer cooperative (SPC) and local experts with the objectives to identify farmers’ selection criteria, to assess farmers’ preferred varieties and to increase the SPC’s variety portfolios. Twelve released bread wheat varieties were evaluated during 2019 cropping season at Sekela district of Amhara region, Ethiopia. Pair-wise ranking was used to identify farmers’ selection criteria and direct matrix ranking to prioritize those selected criteria. Varieties were planted in two sets with and without lime application. Grain yield, followed by earliness, disease tolerance, and tillering capacity, was identified the first preferred criterion by farmers. The mean values showed that higher yield was recorded with the lime application compared to no lime application. Lemu (6.4 t/ha), Alidoro (6.3 t/ha), Dambal (6.3 t/ha), Obora (6.1 t/ha) and Liben (6.1 t/ha) had greater yield with lime application. The t-test results indicated that significant difference between with and without liming for the number of tillers per plant, spike length per plant, plant height, 1000 seed weight, and hectoliter weight, but non-significant difference for grain yield. The selected varieties should be included in the production plan of the cooperatives for large scale production to increase the variety portfolios and to address the demand of the farming community.

Integrating plant morphological traits with remote-sensed multispectral imageries for accurate corn grain yield prediction.

Sustainable crop production requires adequate and efficient management practices to reduce the negative environmental impacts of excessive nitrogen (N) fertilization. Remote sensing has gained traction as a low-cost and time-efficient tool for monitoring and managing cropping systems. In this study, vegetation indices (VIs) obtained from an unmanned aerial vehicle (UAV) were used to detect corn (Zea mays L.) response to varying N rates (ranging from 0 to 208 kg N ha-1) and fertilizer application methods (liquid urea ammonium nitrate (UAN), urea side-dressing and slow-release fertilizer). Four VIs were evaluated at three different growth stages of corn (V6, R3, and physiological maturity) along with morphological traits including plant height and leaf chlorophyll content (SPAD) to determine their predictive capability for corn yield. Our results show no differences in grain yield (average 13.2 Mg ha-1) between furrow-applied slow-release fertilizer at ≥156 kg N ha-1 and 208 kg N ha-1 side-dressed urea. Early season remote-sensed VIs and morphological data collected at V6 were least effective for grain yield prediction. Moreover, multivariate grain yield prediction was more accurate than univariate. Late-season measurements at the R3 and mature growth stages using a combination of normalized difference vegetation index (NDVI) and green normalized difference vegetation index (GNDVI) in a multilinear regression model showed effective prediction for corn yield. Additionally, a combination of NDVI and normalized difference red edge index (NDRE) in a multi-exponential regression model also demonstrated good prediction capabilities.

Comparative analysis of wheat and barley yield performance across temperate environments

ContextA comparative analysis of grain yield performance of wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) under different environments constitutes a way to identify restrictions in yield formation between both crop species. However, most of the previous studies on these field crops have been carried out in Mediterranean environments. ObjectiveThis study aims to compare the grain yield performance of wheat and barley across a wide range of temperate environmental conditions. MethodsWheat and barley yield databases from the national network of cultivar evaluation of Argentina were assembled. The database included 191 wheat cultivars (with early-, mid- and late-flowering length cycle), 140 barley cultivars, and 44 combinations of sites and years of the Argentine wheat and barley belt region. Average heading date variation among environments and crops was no more than 10 days. Crop grain yield comparisons were carried out using a regression analysis, benchmarking within each site-year the grain yield of each cultivar against the average grain yield of all crop cultivars (i.e., environmental index). ResultsThere were no differences in grain yield between wheat and barley for all data, but the behavior between crop species changed with the length of the wheat cycle (i.e., early-, mid-, or late-flowering cultivars). Barley portrayed a greater grain yield than early-flowering wheat under low-yielding environments (< 6060 kg ha−1), but this advantage vanished as the yield environment improved. Mid-flowering wheat showed a similar grain yield to barley across temperate environments. Lastly, late-flowering wheat outperformed barley mainly in high-yielding environments (> 6138 kg ha−1). Grain number m−2 was the main numerical component that explained variability in grain yield. The relative contribution of the yield numerical components differed between species, having barley lower grain number m−2 but a greater grain weight than wheat. ConclusionsThe comparison of the grain yield performance between species represents a strategy to adjust the rotation system, being a critical factor in considering the variability in the crop growth cycle.

Grain Yield and Yield Attributes of Currently Popular Hybrid Rice Varieties Compared to Representative Super Hybrid Rice Varieties in Subtropical Environments

Understanding the yield attributes of the popular rice (Oryza sativa L.) hybrids can provide useful information for developing new hybrid rice varieties. Field experiments were conducted at two subtropical sites (Hengyang and Xingyi) in two years (2021 and 2022) to compare grain yield and yield attributes of three currently popular hybrid rice varieties (Jingliangyouhuazhan, Jingliangyou 534, and Longliangyouhuazhan) with three representative super hybrid rice varieties (Y-liangyou 1, Y-liangyou 2, and Y-liangyou 900). No significant differences in grain yield were observed between the group of popular hybrids and the group of super hybrids at Hengyang and Xingyi in 2021 or at Xingyi in 2022, but at Hengyang in 2022, the group of popular hybrids produced a 15% higher grain yield. The grain yield at Hengyang in 2022 was lower than that at Hengyang and Xingyi in 2021 and at Xingyi in 2022. At Hengyang in 2022, the group of popular hybrids had 9–15% higher panicles per m2, spikelet filling percentage, and harvest index but similar spikelets per panicle and total biomass production and 12% lower grain weight compared to the group of super hybrids. Correlation plot analysis showed that grain yield was significantly related to panicles per m2 but not other yield attributes across six varieties at Hengyang in 2022. These results indicated that the currently popular hybrid rice varieties had higher yield performance than the representative super hybrid rice varieties under the condition of relatively lower productivity, and the key factor for this higher yield performance in the popular hybrids was the higher panicles per m2. This finding highlights that more attention should focus on the yield performance under medium- and low-productivity conditions in hybrid rice breeding programs, and an effective breeding strategy is to select the varieties with high panicle numbers.

Leaf photosynthetic performance is not a key factor affecting grain yield in spring wheat subjected to heat and combined heat and drought stresses

AbstractThe yield traits and physiological responses of three wheat genotypes were studied when subjected to heat and combined heat and drought stress at anthesis under either aCO2 (400 ppm) or eCO2 (800 ppm) in a greenhouse. The heat treatment was 7‐days at day/night 35/28°C, and the combined heat and drought was withholding irrigation from the heat‐stressed plants until the photosynthetic rate reached &lt;5 μmol m−2 s−1. The LM62 genotype had higher photosynthetic rate compared with LM19, though no significant difference in grain yield was found. eCO2 increased photosynthesis at 35°C and significantly lowered the electron transport rate at high intercellular CO2 concentrations. Maximum velocity of Rubisco carboxylation (Vcmax) and the maximum velocity of RuBP regeneration in leaves (Jmax) increased in 35°C compared with 25°C, though when normalized to 25°C both Vcmax and Jmax decreased in the heat‐stressed plants, indicating that an inhibition had occurred. The maximum photochemical efficiency of photosystem II (Fv/Fm) decreased under heat, which correlated with the yield loss caused by the stress. Fv/Fm also decreased under combined heat and drought, though it did not related to the declined yield. A small leaf area prolonged the drying period of Gladius, and it was the genotype with the lowest decrease in yield because of stress. It is concluded that the effects of heat and combined heat and drought stress on the gas exchange and photosynthetic capacity on leaf area basis are not directly linked to the yield performance among wheat genotypes, while the morphological characteristics of the plants are important determinants of grain yield in response to those abiotic stresses.

Response of Winter Wheat to Delayed Sowing and Varied Nitrogen Fertilization

Common wheat is one of the most important cereal crops in the world. In cultivation, winter, spring, and facultative varieties of this species are known. In wheat agronomy, timely sowing and optimal nitrogen fertilization are particularly crucial practices, as both significantly impact yield and grain quality. In a three-year field experiment, the response of the winter wheat variety RGT Kilimanjaro to two sowing dates (recommended and delayed by 30 days) and varied nitrogen fertilization levels (100 kg ha−1, 150 kg ha−1, and 200 kg ha−1) was investigated. It was shown that the difference in grain yield between 2021 and 2023 amounted to 0.74 kg ha−1. The application of 200 N kg ha−1 significantly increased the Soil Plant Analysis Development (SPAD) index and Leaf Area Index (LAI) compared to the variant with a delayed sowing date and a nitrogen dose of 100 kg ha−1. Yield components (number of spikes per square meter, thousand grain weight) and grain yield were highest when wheat was sown at the recommended date and with the application of either 150 or 200 N kg ha−1. The number of grains per spike significantly varied between the variant with the recommended sowing date and a dose of 200 N kg ha−1 and the variant with a delayed sowing date and a dose of 100 N kg ha−1. The lowest grain yield was obtained at a 30-day late wheat sowing date when applying 100 N kg ha−1. The protein content in the grain was primarily influenced by nitrogen fertilization. Therefore, it can be concluded that delaying the sowing date of winter wheat by 30 days results in a decrease in grain yield but can be compensated by increased nitrogen fertilization. The most favorable economic effects were achieved with the application of 150 N kg ha−1 at the recommended sowing date. Considering that high doses of nitrogen fertilization can have adverse effects on the natural environment, research in this area should be continued.

Using Aerial Spectral Indices to Determine Fertility Rate and Timing in Winter Wheat

Tiller density is indicative of the overall health of winter wheat (Triticum aestivum L.) and is used to determine in-season nitrogen (N) application. If tiller density exceeds 538 tillers per m2 at GS 25, then an N application at that stage is not needed, only at GS 30. However, it is often difficult to obtain an accurate representation of tiller density across an entire field. Normalized difference vegetative index (NDVI) and normalized difference red edge (NDRE) have been significantly correlated with tiller density when collected from the ground. With the advent of unmanned aerial vehicles (UAVs) and their ability to collect NDVI and NDRE from the air, this study was established to examine the relationship between NDVI, NDRE, and tiller density, and to verify whether N could be applied based on these two indices. From 2018 to 2020, research trials were established across Virginia to develop a model describing the relationship between aerial NDVI, aerial NDRE, and tiller density counted on the ground, in small plots. In 2021, the model was used to apply N in small plots at two locations, where the obtained grain yield was the same whether N was applied based on tiller density, NDVI, or NDRE. From 2022 to 2023, the model was applied at six locations across the state on large scale growers’ fields to compare the amount of GS 25 N recommended by tiller density, NDVI, and NDRE. At three locations, NDVI and NDRE recommended the same N rates as the tiller density method, while at two locations, NDVI and NDRE recommended less N than tiller density. At one location, NDVI and NDRE recommended more N than tiller density. However, across all six locations, there was no difference in grain yield whether N was applied based on tiller density, NDVI, or NDRE. This study indicated that UAV-based NDVI and NDRE are excellent proxies for tiller density determination, and can be used to accurately and economically apply N at GS 25 in winter wheat production.

The Effects of Different Sowing Dates on Winter Wheat

Three separate field experiments, with different sowing dates, were conducted to determine a suitable sowing date for the highest agromorphological traits and tech- nological quality parameters. The results in growing season 2022–23 demonstrated the following: with a sowing date delay (i.e., with the second sowing date occurring on November 4, 2022), the grain yield was significantly advanced when compared to the first sowing date (occurring on October 13, 2022), while the grain yield was significantly increased in eight genotypes (out of a total of twelve of them) on the third sowing date (i.e., on November 14, 2022) when compared to the first. The rea- son for disproportions of grain yield on the first two sowing dates was the attack of barley yellow dwarf virus in autumn that seriously damaged more developed plants pertaining to the first sowing date, whereafter they were also more prone to other wheat diseases. The relative differences concerning the second sowing date with regard to the first one were as follow: an increase by 59.1% concerning the grain yield, by 6.3% concerning the test weight, and by 22.5% concerning a 1000 kernel weight, a decrease by 23.3% concerning the heading date, by 1.2% concerning the protein content, by 2.1% concerning the wet gluten content, and by 2.5% concerning the sedimentation value. The difference in grain yield between the second and the third sowing date amounted to 34.2% due to a premature senescence of plants in later sowing, as a result of increased June temperatures.

Productivity of winter pea under the application of nitrogen fertilization and biological preparations in the Steppe of Ukraine

Purpose. To determine the elements of the yield structure and the level of crop productivity under the effect of the studied agronomic practices. Methods. Field, agrochemical and statistical methods were used in the study. Results. The results of experiments on the effect of nitrogen fertilization and biological preparations on the yield structure formation and the productivity of winter pea in the Steppe of Ukraine are presented. It was determined that the winter pea varieties ‘Enduro’ and ‘NS Moroz’ formed different plant densities: 78 plants/m2 and 77 plants/m2, respectively. With the application of biological preparations Leanum Humikor and Mycofriend, plant density increased by an average of 3%. The number of beans and seeds per plant and the weight of grain for the application of fertilizers in ‘Enduro’ was on average 11.3 and 30.6, respectively, and for the application of biological preparations 11.0 and 28.6, respectively. In ‘NS Moroz’, these indicators were 15.6 and 27.1, respectively, for the application of fertilizers and 15.5 and 27.1, respectively, for the application of biological preparations. The grain weight was 4.5–4.3 g in ‘Enduro’ and 4–3.8 g in ‘NS Moroz’. A high grain yield of 3.83 t/ha and 3.82 t/ha was obtained in both ‘Enduro’ and ‘NS Moroz’, respectively, after applying the Mycofriend + N40. In the treatments where the main fertilizers N10Р46К0 + N40 and N64Р46К0 + N40 were applied in spring, the yield was 3.15 t/ha and 3.08 t/ha in the ‘Enduro’ variety and 3.15 t/ha and 3.24 t/ha in the ‘NS Moroz’ variety, respectively. Conclusions. The application of biological preparations increased grain yield of winter pea compared to the use of additional doses of nitrogen fertilizers. The difference in grain yield between the fertilization options and the application of biological preparations was 0.67–0.74 t/ha in ‘Enduro’ and 0.59–0.68 t/ha in ‘NS Moroz’, respectively. To obtain high productivity of winter pea, the most effective agronomic practice is the application of fertilizers and biological preparations during autumn sowing, which helps to reduce the influence of changing soil and climate conditions in the period of plant organogenesis, and obtain optimum yield structure.

Yield Stability Analysis of Some Promising Barley Genotypes under Different Environmental Conditions

To mitigate the impact of climate change on barley production, adaptation strategies are crucial including developing and promoting drought-tolerant barley genotypes that can withstand higher temperatures. This study aimed to evaluate twenty different barley genotypes under different conditions, specifically normal, heat stress, and rain-fed conditions during 2019/2020 and 2020/2021 growing seasons. This study was conducted as part of breeding programs aimed at developing agricultural genotypes that can adapt to changing environments. The experiment involved evaluating the performance of the twenty barley genotypes at three different locations: Sakha for the normal condition, New Valley Station for the heat stress condition, and Marsa Matruh for the rain-fed condition. The analysis of variance showed that there were significant differences in grain yield among the different genotypes and locations, as well as the interaction between genotypes and locations. This indicates that the genotypes responded differently to the different locations, and further analysis is needed to determine their stability. The average grain yield ranged from 9.9 to 16.0 arddab fad-1 (Faddan=4200m2) for Giza 135 and Line 5, respectively, across all three locations in both seasons, this shows that there is variation among the genotypes. Considering GGE biplot and stability analyses, Giza 126, Giza 2000, Giza 134, Giza 137, Giza 138, Line1, Line 2, Line 3, Line 4 and Line 5 showed the best performances, suggesting their adaptation to a wide range of environments. This suggests that these genotypes perform well in relation to the linear component of the genotype-by-environment interaction. Overall, this information can be used by plant breeders to select genotypes that are not only high-yielding but also stable across different environments.

Improving the Allocation of Light-Temperature Resources and Increasing Yield of Rice through Early Sowing and Increasing Nitrogen

This study explored the effects of the sowing stage and nitrogen application rate on the grain yield and its allocation of light-temperature resources over a 9-year experiment from 2011 to 2019. Measurement indicators include the effective accumulative temperature on different growth durations, leaf area index (LAI), above-ground biomass production, and harvest index (HI). Methods: A split-plot design was arranged in the treatment, with N supply as the main plot and the sowing stage as the subplot. The main plots consisted of two nitrogen treatments: low nitrogen (LN: 120 kg ha−1) and high nitrogen (HN: 180 kg ha−1). The subplots contained two sowing stages: the early sowing stage (ES) and the late sowing stage (LS). Results: Compared with LNLS, LNES, and HNLS from 2011 to 2019, HNES of HHZ increased the grain yield by 9.5%, 2.5%, and 5.3%, while the difference in grain yield in YY8 was higher than HHZ, especially under HNES. Compared with LNLS, LNES, and HNLS from 2011 to 2019, HNES of HHZ increased the panicle number by 6.0%, 5.9%, and 1.0%, and HNES of YY8 increased by 12.7%, 11.4%, and 3.8%. Compared with HNLS of HHZ, LNES, LNLS, and HNES decreased the spikelets per panicle by 2.3%, 2.9%, and 1.1%, and decreased by 3.5%, 1.9%, and 2.2% in YY8. The early sowing or increasing N supply significantly increased the dry matter accumulated, grain weight, LAI, and HI. The higher grain yield in LNES was more closely related to the average temperature and the number of spikelets per panicle. The grain yield in HNES was more dependent on the effective accumulative temperature. Conclusions: Sowing in mid-May and increasing the N application (180 kg ha−1) are beneficial to the allocation of light temperature and the increase in yield. Therefore, this research provides a theoretical basis for improving rice yield and optimizing the utilization of light-temperature resources in the future.

Yield and nutritional responses of quinoa (Chenopodium quinoa Willd.) genotypes to irrigated, rainfed, and drought-stress environments

This study aimed to select higher-yielding and drought-tolerant quinoa (Chenopodium quinoa Willd.) lines suitable for cultivation in the U.S. Midwest, where water scarcity poses a common challenge for crop production. Quinoa, known as a superfood and climate-smart crop, is rich in nutrients, possesses resilience to abiotic stress, and is ideal for sustainable food production and supporting nutritional security in the face of changing climate conditions. To achieve this goal, 128 quinoa germplasms, collected from the USDA-ARS-GRIN, were evaluated. Among those lines, ten quinoa lines were selected for further assessment and evaluated at four different locations in Missouri, United States. Evaluations were conducted under three environments: irrigated, rainfed, and drought stress, over 2 years (summer of 2021 and 2022). Two of the selected ten lines, Ames13746 and PI614927, produced higher yields across various locations and environments. Remarkably, these lines demonstrated significantly higher grain yields under drought stress compared to irrigated and rainfed conditions. However, there was no significant difference in grain yield between irrigated and rainfed environments. Notably, despite the presence of moisture stress, the concentration of essential amino acids remained unaffected, while there was a slight decrease in the total protein content under drought-stress conditions. These research results and selected genotypes can potentially facilitate quinoa production in the U.S. Midwest regions prone to water stress, contributing to food security and sustainable agricultural practices.

Agronomic characterization of pigmented native corn populations (Zea mays L.)

Objective: To characterize agronomically 52 populations of pigmented native corn (Zea mays L.) from Coahuila, Mexico, in order to identify varieties with outstanding agronomic potential and to establish an improvement program with potential for grain yield, with the ability to adapt, and superior nutritional bioactive content. Design/Methodology: Two experiments were evaluated through an incomplete block design in lattice alpha arrangement, in two localities that are representative of the agricultural area of southeastern Coahuila: a) Yellow populations, mostly of Tuxpeño, Ratón and Tuxpeño Norteño; and b) Anthocyanin populations (blue, red and purple), represented primarily by Cónico Norteño, Elotes Cónicos and Ratón. Results: There is an environmental effect that contrasts between localities, with differences in grain yield of up to 78%; 25 days of difference in flowering, 53 cm in plant height, and up to seven plants without cobs. The response was product of the agricultural potential in each locality. The outstanding yellow populations due to their superior yield expression in both localities were the landraces Tuxpeño: COAH068, COAH089, COAH177 and COAH215, and Celaya: COAH075. The outstanding anthocyanin populations were Ratón: COAH23 and COAH203; Elotes Cónicos: COAH246 and COAH019; and Elotes Occidentales: COAH021; in addition, the study found populations adapted to a locality. Conclusion: Among the diversity of the pigmented native corn in Coahuila, there are populations with superior agronomic expression that can be the basis for improving the production, the nutritional quality of the grain, and therefore, of its byproducts.

Effect of Polythene Covering on Seedling Quality and It’s Carryover Effect on Field Duration and Grain Yield of Rice

Boro rice cultivation is often limit due to lack of a farmer's friendly technique for raising quality seedling in irrigated ecosystem. Experiment was conducted in Boro 2019-20 at R/S Rangpur to compare different polythene covering treatment on raising quality seedling of BRRI dhan88 and BRRI dhan89 and to measure it’s carryover effect on growth duration and grain yield of rice. The treatments were as T1: Day polythene cover (from10:00 am to Sunset), T2: Night polythene cover (Sunset to Sunrise), T3: Day-night polythene cover but round shape opening (30 cm diameter) at both sides and T4: No polythene cover (control). Seedbed was covered by transparent polythene from seeding to 30 days after seeding (DAS). Seedling strength was higher on 01 December seeding than 15 December in both the tested varieties. Day cover always had the lowest seedling strength in both varieties. Day-night polythene cover treatment (T3) produced significantly tallest seedling than other polythene covering treatments for both the plantings dates. Seedling mortality was higher in 30 January planting than 15 January planting for both the tested varieties due to prevailing low temperature (below 10°C for eight days). In 15 January planting, BRRI dhan88 and BRRI dhan89 produced higher number of tillers with day cover and night cover treatment, respectively. In 30 January planting, BRRI dhan88 produced higher tiller with day-night and control treatment but day cover had the lowest. Tiller production rate was sharply increased from 35 – 45 DAT and then decreased. Up to 45 DAT, it was statistically similar in both the varietiers with all treatments. Although, tiller number was higher in T1, T2 and T4 than T3 but productive tiller (%) was satistically similar among the treatments for both the varieties and planting dates. There was no significant difference in grain yield among the treatments for planting dates and varieties. Day-night polythene cover treatment (T3) reduces growth duration by 2-3 days over other treatments. This treatment (T3) is farmer's friendly for raising quality seedling in cold prone areas of Bangladesh. Bangladesh Rice J.26 (1): 59-68, 2022