Physiological traits can help explain cassava’s (Manihot esculenta Crantz) health and identify superior genotypes for breeding programs. The study objective was to evaluate the performances of various cassava genotypes based on chlorophyll fluorescence, total crop dry weight, and storage root dry weight. The 100 cassava genotypes grown under field conditions ensued from May 2020 to May 2021 (2020–2021) and from May 2021 to May 2022 (2021–2022) at the Field Crop Research Station of Khon Kaen University, Thailand. The chlorophyll fluorescence measurements commenced 3, 6, 9, and 12 months after planting (MAP). Recording of storage root and total crop dry weights occurred at 12 MAP. The results revealed that the appropriate time to observe chlorophyll fluorescence was at 6 and 9 MAP, relating to cassava’s dry weight at the final harvest. Huay Bong 90 proved a superior genotype for storage root and total crop dry weights at 12 MAP and chlorophyll fluorescence at 6 and 9 MAP for both growing season years. A genotype CMR 38-125-77 also performed well in chlorophyll fluorescence for both growing seasons, and it was a distinct top genotype for the 2020–2021 growing season and ranked third for the 2021–2022 growing season based on total crop dry weight at 12 MAP. These genotypes could benefit as an alternative germplasm for cultivation and future breeding programs.

Keywords: Breeding, cassava (Manihot esculenta Crantz), dry weight, physiology, selection, storage root

Key findings: The appropriate growth stages to evaluate chlorophyll fluorescence that relate to dry weight at the final harvest of cassava (M. esculenta Crantz) germplasm were 6 MAP for F_v‘/F_m‘ and 6 and 9 MAP for F_v/F_m. Cassava germplasm classification for this study depended on F_v‘/F_m‘, F_v/F_m, total crop dry weight, and storage root dry weight. The desirable cassava genotypes for both growing seasons were Huay Bong 90 and CMR 38-125-77.

The article evaluated the genetics of six cucumbers (Cucumis sativus L.) cultivars and 30 hybrids based on morpho-yield traits. The dominant and epistatic gene effects managed the fruit weight in three cucumber hybrids (C-25/1, A-6, and A-9), while additive gene effects in three other hybrids were supreme. For productivity per plant, dominant genes with epistatic effects controlled these in three accessions, while additive effects played a special role in manifesting the trait in three other hybrid (C-25/1, A-6, and A-9) genes. Likewise, dominant genes with epistatic effects controlled the yield per plant trait in three accessions, while additive effects influenced the attribute in three other hybrids (C-25/1, A-6, and A-9). According to these traits, the promising hybrids were С-25/1 х С-25/2, С-26 х С-25/2, С-26 х С25/1, А-9 х С-26, and А-6 х С-25/1. The cucumber F1 hybrids C-26 x C-29, A-9 x A-6, and A-9 x C-25/2 showed characteristics of large fruits weighing 108.2 to 113.1 g. In the accessions, C-25/1, A-6, and A-9, the additive gene effects dominated the studied trait (σ2ĝi > σ2si). The superior-in-yield hybrid combinations were C-26 x C-29, A-9 x A-6, and A-6 x A-9, with a total fruit yield of 691 to 769 g per plant.

Keywords: Cucumber (Cucumis sativus L.), diallel crosses, general and specific combining ability, female flowering, fruits, physiological maturity, productivity

Key findings: The study enunciated that in cucumber (C. sativus L.), the average fruit weight bore control from dominant genes with epistatic effects in three accessions (C-25/1, A-6, and A-9), and additive gene effects were vital in three other accessions. The fruit productivity per plant also had dominant and epistatic gene effects managing the trait in three accessions, while in three others (C-25/1, A-6, and A-9), the additive gene effects manifested most in the trait. The promising hybrids, viz., C-26 x C-29, A-9 x A-6, and A-6 x A-9, performing best were choices to serve as source material for further selection.

The availability of sorghum varieties with good cooking quality will increase its use as a food source and for industrial needs. Amylose content is one of the biochemical characteristics that influence cooking quality. This study aimed to scrutinize the inheritance patterns of agronomical traits and amylose content in segregating the sorghum population. The field experiment was conducted from February to July 2022 at Cikarawang Experimental Field, IPB University, Bogor, Indonesia. The three F₂ populations, Pulut 3 × Kawali (372 plants), Pulut 3 × Soraya 3 IPB (340 plants), and Pulut 3 × PI-150-20A (363 plants) and their parental genotypes were evaluated. The three populations showed significant variations in agronomic traits. The panicle weight has a heritability value of 63% in Pulut 3 × Kawali, 36.7% in Pulut 3 × Soraya 3 IPB, and 59.8% in Pulut 3 × PI-150-20A. The waxy and non-waxy type segregation was apparent in F3 population seeds, with a 15:1 ratio in the Pulut 3 × Soraya 3 IPB and Pulut 3 × PI-150-20A populations. Meanwhile, a 1:1 ratio was evident in the Pulut 3 × Kawali population. Selection could be conducted for waxy type at early generation followed by selection for yield at later generation.

Keywords: Sorghum (S. bicolor L.), cereal, breeding, genetic variations, segregating populations, starch, waxy

Key findings: The research produced information on genetic control of yield and sorghum (S. bicolor L.) type based on amylose content. This information would assist the food crop breeders in designing a breeding program for selection methods and criteria for developing high-yielding varieties and low-to-medium amylose content.

Cotton is a valuable industrial fiber crop grown in many regions worldwide. Four cotton (Gossypium hirsutum L.) cultivars, i.e., Ishonch, Navbakhor-2, C-6524, and Tashkent-6, and their F_1-2 diallel hybrids’ cultivation comprised a randomized complete block design with a factorial arrangement and four replications during 2019–2021 in the Tashkent Region, Uzbekistan. Significant (P ≤ 0.01) differences were notable among the parental genotypes and their F₁ hybrids for boll weight and seed cotton yield. The parental cultivars Ishonch and Navbakhor-2 and their F₁ diallel hybrids showed more stability and performed better than other genotypes. Broad-sense heritability estimates were the highest for boll weight and seed cotton yield while lowest for bolls per plant. Based on this trait’s yield, heritability, and variability, the inbreeding depression was positive in the F₂ populations Ishonch × Navbakhor-2 and Navbakhor-2 × Tashkent-6. According to yield, the cultivars Ishonch, Navbakhor-2, and Tashkent-6 were outstanding as positive donors.

Keywords: Cotton (G. hirsutum L.), genetic variability, heritability, genetic gain, correlation coefficient, heterosis, inbreeding depression

Key findings: Cotton (G. hirsutum L.) cultivars Ishonch, Navbakhor-2, Tashkent-6, and their F₁ diallel hybrids performed better for bolls per plant, boll weight, and seed cotton yield per plant.

Soybean (Glycine max L.) is one of the most essential sources of high-grade protein and oil. Although growing soybeans can occur in different environmental conditions and are very productive in warm temperatures, their cultivation in cold climates, including Northern Kazakhstan, leads to considerable yield losses. The presented study sought to investigate soybean cultivars growing in the cold climate of northern Kazakhstan and find the optimal ratio of the growing season duration and crop yields. Soybean productivity and the cropping season length revealed a significant negative correlation. Early flowering is one of the relevant approaches for reducing the growing season and improving soybean seed production. A MADS-box SEPALLATA3 (GmSEP3) gene expression, known to promote regular and early flowering, received analysis. The GmSEP3a expression in soybean cultivars with high yield was also valid, with a significant positive correlation between GmSEP3a expression and soybean yield. The soybean cultivars, viz., Suiyang 1, Sibiryachka, No. 86, Niva, and Beidou 43 surfaced as high-yielding cultivars under environmental conditions of Northern Kazakhstan. The pertinent study revealed that the GmSEP3a gene can become a gene marker for screening early-ripening soybean cultivars with high yields in low-temperate climates. The promising results can also help identify potential soybean cultivars for cold-weather cultivation.

Keywords: Soybean (Glycine max L.), early maturing cultivars, growing season duration, productivity, plant height, transcription factors, warm and cold climate

Key findings: The study highlights the need to enhance soybean yields in Kazakhstan, focusing on early ripening cultivars. The GmSep3a gene correlates with high yields and early ripening, offering a potential genetic marker for breeding. Among 90 cultivars analyzed, only five exceeded 10 t/ha, which shows promise for further improvement. This gene marker could aid in developing soybean cultivars suited for cold climates like Kazakhstan.

Nowadays, drip irrigation is a promising technology for optimizing plant development conditions and allowing the introduction of necessary nutrients to plants. The study aimed to establish the effects of drip irrigation with various levels of foliar dressing of mineral fertilizer Kristalon on maize (Zea mays L.) and achieve its maximum genetic potential for grain yield to enhance overall production. A field experiment implies exploratory research and quantifies the effects of drip irrigation with foliar Kristalon dressing to validate and introduce scientific achievements in agricultural production. Various technological methods applied to corn cultivation sought to increase its green mass and yield. In the experimental treatments, the corn crop irrigation engaged drip irrigation with different foliar dressings of Kristalon in the phases of the 5th and 11th tillering leaf and stem elongation with the norms of 2, 4, and 6 kg Kristalon ha^-1, respectively, in comparison with the control treatment (no Kristalon foliar dressing). Corn foliar treatment with fertilizer Kristalon preparation with a norm of 2, 4, and 6 kg ha^-1 produced grain yields of 11.43, 12.27, and 12.33 t ha^-1, respectively, compared with the control treatment (9.67 t ha^-1). The fertilizer Kristalon at 2, 4, and 6 kg ha^-1 produced 18.2%, 26.9%, and 27.5% more grain yield than the control. However, the Kristalon foliar dressing at 6 kg ha^-1 did not significantly increase the maize grain yield, and there was an increase of 0.6% compared with the 4 kg ha^-1 level. Therefore, corn foliar dressing with fertilizer Kristalon at 4 kg ha^-1 is an option for better production under the environmental conditions of South Kazakhstan.

Keywords: Maize (Zea mays L.), grain corn, drip irrigation, foliar dressing, mineral fertilizer Kristalon, yield components, grain yield

Key findings: Assessment of drip irrigation with mineral fertilizer Kristalon foliar dressing revealed that Kristalon preparation at 4 kg ha^-1 in the phases of 5th and 9th leaf tillering and stem elongation is recommendable for getting maximum grain yield at the Zhambyl Region, South Kazakhstan.

Elevating plant density and improving N fertilizer rate for high density-tolerant genotype can maximize maize (Zea mays L.) grain productivity per unit land area. This investigation’s objective sought to evaluate the effects of stresses resulting from increasing plant density combined with reducing N application rate on traits of eight inbred lines and their diallel F₁ crosses. Choosing eight maize inbred lines differing in tolerance to low N and high density (D) were samples for diallel crosses. Parents and crosses’ evaluation ensued in the 2020 and 2021 seasons under three plant densities: low (47,600), medium (71,400), and high (95,200) plants/ha, and three N fertilization rates: low (95 kg N/ha), medium (285 kg N/ha), and high (476 kg N/ha). Elevating plant density from 47,600 to 71,400 and 95,200 plants/ha caused a significant decrease in grain yield/plant by 25.43% and 30.15% for inbred parents and 17.92% and 25.65% for F₁ crosses, respectively. This reduction correlated with significant decreases in all yield components but caused a notable increase in grain yield/ha by 13.69% and 27.33% for inbreds and 20.99% and 44.69% for F₁ crosses, respectively. The best combination of plant population density and N level for giving the highest grain yield/ha was high N (476 kg N/ha) × high density (95,200 plants/ha) for all inbreds and all F₁ crosses.

Keywords: Maize (Zea mays L.), high-density, low-N, unit area productivity

Key findings: The results will help maize (Zea mays L.) breeders match the functions of optimum plant density with adequate nitrogen fertilizer application to produce the highest possible yields per land unit area with the supreme maize genotype efficiency.

For improvement and rational use of rainfed lands, a study on the influence of different tillage methods proceeded on the soil-water physical relationship and soil agrochemical properties in Southeast Kazakhstan. In the arable soil layer (0–30 cm), the soil density during the studied crop’s life from sowing to harvesting, enhanced to a medium compacted state with the traditional method of tillage (1.28–1.29 g/cm³), slightly higher with the minimum tillage (1.30–1.31 g/cm³), and the highest with zero tillage (1.32–1.33 g/cm³). Tillage with better crumbling, dissolution, and superior ingestion of plant vestiges in the cultivated soil layer contributed to a slight decrease in soil density, both with traditional and minimum tillage regimes. Given the least rainfall in summer, there was a decline in the productive moisture reserves in the soil with customary tillage (15.9–34.5 mm). However, the soil moisture enhanced gradually with reduced tillage, i.e., minimal tillage (20.7–36.7 mm) and zero tillage (29.8–54.8 mm). The nitrate nitrogen content in the soil also decreased from the initial state to the cultivated crops’ harvest, and a significant decrease emerged with zero tillage. The prolonged rainless period, accompanied by a decline in relative air humidity, soil moisture, and temperature increases, affected plants’ physiological processes and, eventually, the studied crops’ yield. In the studied crops, on average, acquiring the highest yield of 1.76 t/ha was with minimal tillage. Based on two-way analysis of variance (ANOVA), the contributed share of the crops in the grain yield formation was according to crop season, ranging from 0.73% to 2.89%, and the soil cultivation methods’ share was 83.3%–93.8%. The grain yield formation has a greater dependence on the tillage regimes, although that reliance might vary in association with weather conditions during the crop life. In rainfed conditions of Southeast Kazakhstan, zero tillage results in a significant reduction in nitrate nitrogen compared with conventional and minimum tillage. Therefore, with no tillage, more nitrogen fertilizer is necessary than usual plowing and the application of potash fertilizers, regardless of tillage methods.

Keywords: Conservation agriculture, soil, traditional tillage, zero tillage, soil-water relationship, soil agrochemical properties, crop yield

Key findings: No-tillage results in a significant reduction in nitrate nitrogen in the soil, so no-till requires more nitrogen fertilizer application than conventional tillage. The formation of grain yield depended to a greater extent on the studied methods of soil cultivation, and the dependence only increased, which is associated with weather conditions during the growing season of the studied crops.

The promotion and rational development of drylands employed two tillage regimes (plowing to 20–22 cm and no-till) during the spring wheat and barley cultivation in Southeast Kazakhstan. The results established that the no-till scheme contributed to forming an excellent aggregate state of the arable soil layer for spring wheat and barley (65%–69%). The water-resistant aggregates were the highest with no-tillage (19.3%–21.8%), indicating the unsatisfactory water resistance of the soil structure. Enhancing the water-resistant aggregates requires using organic fertilizers to improve the establishment of perennial grasses, green manuring, and cover crops. No-till system inclined to boost the optimal soil density from a loose and slightly compact state of 1.19–1.23 g/cm³ to a dense 1.32–1.39 g/cm³. According to crop cultivar and tillage methods, the spring wheat and barley grain yield varied between 2.84 and 3.89 t/ha. High grain yield came from the spring barley cultivar Symbat. Spring showed promising performance when the plowing level was 20–22 cm and inferior only by 0.25 and 0.15 t/ha with no-till. Based on the two-factor analysis of variance, the cultivar contribution to the spring wheat and barley grain yield buildup depended on the shares of crop season of the research (year – environment) (40.9%–62.2%) and the tillage regimes (22.4%–32.2%). The grain yield formation was more dependent on the studied crops and their cultivars, and the dependence increased over the crop seasons due to weather conditions during the crop period.

Keywords: spring wheat, barley, soil, soil structure, tillage regimes, no-till, grain yield

Key findings: Structural-aggregate composition and water resistance of soil depended on tillage methods in Southeast Kazakhstan.

Seeking to improve the efficiency of nitrogen fertilizers for grain crops led to conducting this study on developing methods using 15N in 2015–2017 at the Kazakh Research Institute of Agriculture, Almalybak Village, Almaty Region, Southeastern Kazakhstan. Nitrogen use efficiency using the stable isotope 15N in microfield experiments revealed that the assimilation of nitrogen fertilizers by grain crops largely depends on the norms, timing, fertilization method, and varietal parameters of the concerned crop. Based on morphophysiological methods of monitoring plant development conditions, the nitrogen fertilizers’ role based on the development has been affirmative, with the optimal timing of their application also determined. Results show that grain crops use nitrogen productively with partial application at the beginning of tillering and tubing, respectively, and stages III and V of organogenesis. With the use of nitrogen fertilizers, the significant varietal differences were evident. The help of an isotope label established the accurate nitrogen utilization coefficients of fertilizers based on the options ranging from 14.7% to 32.2%. Using the isotope method provides an opportunity for further development of practicing the most efficient techniques of applying fertilizers, which is an imperative method for determining the effectiveness of nitrogen fertilizers.

Keywords: grain crops, microfield experience, stable nitrogen isotope, light chestnut soil, morphophysiology, utilization factor

Key findings: The effect of nitrogen fertilizers on the plant height of grain crops planted on light chestnut soils of Southeast Kazakhstan was distinguishable by a low level of natural fertility. The help of morphophysiological observation methods determined the reasonable period needing nitrogen through nitrogen fertilizers by grain crops nitrogen fertilization. With the help of a stable isotope ¹⁵N, the coefficients of nitrogen use from fertilizers (11.7%–31.7%) attained establishment, which vary based upon the time and methods of application and the varietal characteristics of the grain crops.