Knowledge about germplasm diversity is an invaluable aid in crop improvement strategies. The following research aimed to study the diversity of 53 mustard (Brassica rapa) genotypes. The study had a randomized complete block design with three replications, implemented at the Genetics and Plant Breeding Department experimental field of Bangabandhu Sheikh Mujibur Rahman Agricultural University. The collected germplasms came from the said university and the Bangladesh Agricultural Research Institute. Different multivariate analysis techniques used help classify genotypes across 21 studied characteristics, with all the genotypes grouped into seven clusters. Among the seven clusters, Cluster III had the most genotypes (12) and Cluster IV the least (1). Cluster VII showed the highest intra-cluster distance, and Cluster IV the lowest. The largest inter-cluster distance was between clusters IV and VII, and the smallest was between clusters I and III. Selecting genotypes from clusters with the greatest distances could enhance genetic diversity and heterosis. Genotypes from clusters with moderate to high inter-cluster distances and medium to high yields could be applicable for desirable segregants. Specifically, genotypes G₂, G₁₂, G₁₇, G₃₃, and G₄₄ from Cluster I; G₁, G₁₀, G₃₈, and G₄₀ from Cluster II; G₈, G₁₃, G₂₇, and G₄₃ from Cluster III; G₅₁ from Cluster IV; G₂₁, G₃₄, and G₅₂ from Cluster V; G₂₅ and G₃₇ from Cluster VI; and G₃ and G₄₁ from Cluster VII would be favorable selections as superior parents for hybridization programs.

Keywords: Oil seed, mustard, genetic diversity, morphological characteristics, cluster analysis, and D2 statistic

Key findings: The highest genetic divergence emerged between clusters IV and VII, suggesting that selecting genotypes from these clusters could enhance heterotic F₁ generation and diversity in segregating generations.

The following study comprised the combining ability in parental genotypes and the inheritance of yield-related traits in F₁ hybrids of the Pima cotton (Gossypium barbadense L.). The cotton cultivars, Surkhon-9 and Termiz-32, were notably the high-level donor parental genotypes in seed cotton yield and play a vital role in the development of high-yielding cotton cultivars. In all cultivars (σ2si>σ2gi), the dominant role of non-additive variances was evident in managing the seed cotton yield. Study results showed the cultivar Termez-32 can become a donor parent in developing new cultivars with numerous bolls per plant. By comparing the GCA and SCA variances of cotton cultivars, the bolls per plant reflected the control of non-additive genes (σ2si>σ2gi) in cultivars Surkhon-9, Duru Gavhar, and Surkhon-10. In cultivars Termiz-32 and Bukhoro-7, the bolls per plant had the additive genes (σ2si<σ2gi) managing them. Thus, the inheritance of the seed cotton yield per plant and the number of bolls traits occurred mainly with the positive superdominance in the F₁ cross combinations. An outcome of the presented study revealed the development of the new Pima cotton cultivar ‘Guzor.’

Keywords: Pima cotton (G. barbadense L.), cultivars, diallel crosses, combining ability, inheritance, dominance, yield-related traits

Key findings: Results revealed that Pima cotton (G. barbadense L.) cultivars, Termiz-32 and Bukhoro-7, can be desirable for improving the seed cotton yield, while Surkhon-9 and Termiz-32 can be useful for enhancing bolls per plant of cotton. The said breeding material can be beneficial in the development of high-yielding Pima cotton cultivars.

Diallel analysis undertakes the adequate capture of the interaction of genes contributing to traits’ variation by the general (GCA) and specific combining ability (SCA) effects. However, in reality, the genes’ interaction can be more complex, involving epistatic interactions and pleiotropy, which are unaccounted for in the traditional diallel analysis. Therefore, the presented work sought to study the combining ability in wheat genotypes widely planted in Uzbekistan. The mode of inheritance as studied through combining ability included the vegetation period, plant height, vitreousity, grain weight per ear, 1000-kernel weight, grain yield, and productive accumulation in 4 × 4 F₁ diallel hybrids of wheat. The analysis of variance indicated significant differences among the parental genotypes and their F₁ hybrids in the GCA, SCA, and reciprocal effect of the previously mentioned characters on grain size. Consequently, it helped determine the grain and cultivar quality, as well as the genetic strength of the grain. For management of the grain yield, the GCA and reciprocal effects played major roles compared with the SCA effects. Significant variances due to GCA and SCA showed the predominance of additive, epistatic, and dominant gene effects in controlling the inheritance of the wheat’s studied traits.

Keywords: Bread wheat (T. aestivum L.), F₁ hybrids, diallel analysis, combining ability, additive, epistatic, dominant gene effects, morphological and yield traits

Key findings: Significant variances due to GCA and SCA showed greater genetic variability in the F₁ populations and the predominance of additive, epistatic, and dominant gene effects in managing the inheritance of morphological and yield traits in bread wheat (T. aestivum L.).

In temperate regions, rice production faces substantial threats from the devastating blast disease caused by the fungal pathogen Magnaporthe oryzae. For managing blast disease, deploying resistance genes remains the most cost-effective and environmentally sustainable control strategy. In the following study, a genome-wide association study (GWAS) for rice panicle blast resistance proceeded in germplasm comprising 191 temperate Japonica rice accessions. Results revealed the 141 significant single-nucleotide polymorphisms (SNPs) were notably related to rice panicle blast resistance. Four intervals were considerably confident loci related to panicle blast resistance, including qPBR04, qPBR05-1, qPBR05-2, and qPBR07. The qPBR07 region on chromosome 7 was a promising QTL, having several novel genes with a crucial role in pathogen defense. Key genes, including Os07g0511500, Os07g0515100, Os07g0516300, Os07g0518100, Os07g0513600, Os07g0515200, and Os07g0512100, were seemingly potential genes in response to the M. oryzae pathogen invasion. The study identified 25 temperate Japonica accessions exhibiting a high level of panicle blast resistance, positioning them as potential sources of resistance suited to temperate climates. The insights gained from the presented study provide a valuable foundation for panicle blast resistance breeding and the comprehensive characterization of identified resistance genes.

Keywords: Rice (O. sativa L.), blast disease, panicle blast resistance, quantitative trait locus, genome-wide association study

Key findings: Twenty-five rice genotypes resistant to panicle blast showed distinction from a set of 191 temperate Japonica rice accessions. Four quantitative trait loci (QTLs) associated with rice panicle blast resistance also emerged, with qPBR07 on chromosome 7 showing a high potential for gene mining and breeding application.

The beneficial study aimed to determine the effects of the compound chemical fertilizer and growth regulator brassinolide on the qualitative and productive traits of the date palm Barhi cultivar, carried out in 2023 at the Kerbala Agriculture Directorate, Iraq. The experiment layout had a randomized complete block design (RCBD) with two factors and three replications. The first factor was adding the compound chemical fertilizer at three levels (0, 1000, and 1500 g palm^-1), while the second factor included foliar application of the growth regulator brassinolide with four concentrations (0.0, 0.3, 0.6, and 0.8 mg L^-1). The results showed the date palm variant with compound chemical fertilizer (1500 g palm^-1) was superior in fruit length, diameter, weight, set, bunch weight, and total fruit yield, with average values of 3.079 cm, 2.517 cm, 10.741 g, 74.710%, 14.729 kg bunch^-1, and 117.830 kg palm^-1, respectively. According to the foliar application of brassinolide, it was evident that brassinolide at 0.8 mg L^-1 performed better and excelled for the fruit’s yield-related traits, with average values of 3.208 cm, 2.531 cm, 11.153 g, 76.060%, 15.667 kg bunch^-1, and 125.330 kg palm^-1, respectively. The interaction effects between the factors were significant for all traits.

Keywords: Date palm (Phoenix dactylifera L.), compound chemical fertilizer, brassinolide, qualitative traits, fruit yield traits

Key findings: The results showed superiority of the mineral fertilizer 1500 g palm^-1 and foliar application of the growth regulator brassinolide 0.8 mg L^-1 for the fruit’s yield-related traits in the date palm (P. dactylifera L.).

The study aimed to assess the effects of using rice husk ashes to treat the quality of non-fresh irrigation water on the growth and productivity of the wheat cultivar Al-Rashid in plastic pots. The research occurred during the 2022–2023 season at the Thi-Qar Governorate, Iraq. The randomized complete block design with split-plot arrangement had two factors and three replications. The main plots were the irrigation water quality (W), comprising river water 2.1 dSm^-1 (W1), city sewage water 6.4 dSm^-1 (W2), and drainage water 12.3 dSm^-1 (W3). The subplots were the ashes of rice husks (T) burned at temperatures of 1000 °C (T1), 800 °C (T2), 600 °C (T3), and 400 °C (T4). The burned rice husk (T1) showed a significant positive effect on the growth and yield traits, i.e., plant height, leaf area, tillers per plant, grains per spike, and grain yield (113.67 cm, 62.86 cm², 9.73 tillers plant^-1, 65.22 grains spike^-1, and 7.438 t ha^-1, respectively). Drainage water caused a decrease in average values of studied traits compared with the river water. The river water exhibited a significant positive effect and provided the highest means for the above traits (118.42 cm, 63.66 cm², 10.32 tillers plant^-1, 71.58 grains spike^-1, and 7.967 t ha^-1, respectively). The interaction of river water (2.1 dSm^-1) and burned rice husks (1000 °C) (T1 and W1) gave the maximum grain yield (8.212 t ha^-1).

Keywords: Wheat, lack of water revenues, rice husk ashes, irrigation water quality, growth and yield traits

Key findings: The study revealed that increasing the temperature of burning rice husks to treat irrigation water can improve the mean values of studied traits.

The presented study sought to determine the effect of sulfur, thiobacillus bacteria, and nano-zinc on biochemical and grain yield traits of maize (Zea mays L.) grown in calcareous soils. The experiment, laid out in a randomized complete block design with three factors and three replications, commenced in the spring of 2022 at the Ibn-Al-Bitar Vocational Preparatory School, Holy Kerbala Governorate, Iraq. The first factor comprised three doses of agricultural sulfur (0, 1500, and 3000 kg ha^-1), the second was two thiobacillus bacteria levels (control – no addition, and bacterium), and the third factor was the nano-zinc concentrations (0, 50, and 100 mg L^-1). The sulfur addition (3000 kg ha^-1) showed the highest grain yield (8.06 mg ha^-1) with percent of nitrogen (1.72%), phosphorus (0.53%), protein (10.79%), and sulfur (0.270%) in maize grains. The thiobacillus bacteria also exhibited the maximum 500-grain weight and grain yield (154.64 g and 7.52 mg ha^-1, respectively). For nano-zinc, the optimum level (100 mg L^-1) excelled in nitrogen (1.62%), phosphorus (0.41%), protein (10.79%), and sulfur (0.239%) in maize grains and 500-grain weight (155.53 g); however, nano-zinc (50 mg L^-1) outshone in grain yield (8.01 mg L^-1). The combine application of three factors also improved most biochemical traits of maize.

Keywords: Maize (Zea mays L.), agricultural sulfur, thiobacillus bacteria, nano-zinc, biochemical traits, grain yield

Key findings: Results showed sulfur’s highest level (3000 kg ha^-1) was superior in enhancing maize (Zea mays L.) grain yield and biochemical traits. The treatments with bacteria (thiobacillus) and nanozinc (100 mg L^-1) also excelled in all maize traits.

This study, conducted at the College of Agriculture and Marshlands, Thi-Qar University, commenced during the 2019–2020 season on 36 three-year-old offshoots of date palm (Phoenix dactylifera L.) cultivar Lulu, produced from tissue culture. The research aimed to know the impact of Calmax and Stimplex and their interactions on the leaf contents of flavonoids, glutathione, vitamin C, and the superoxide dismutase enzyme. The results showed the significant superiority of the Calmax treatment at a concentration of 4 ml L^-1, recording the highest averages (11.61 mg g^-1, 12.42 μmol g^-1, 1.50 mg g^-1, and 14.06 unit g^-1 f.w.), respectively, compared with the control treatment. The Stimplex treatment at a concentration of 12 ml L^-1 showed notable superiority, with maximum averages of 13.30 mg g^-1, 13.02 μmol g^-1, 1.55 mg g^-1, and 16.61 unit g^-1 f.w., respectively, versus the control treatment. The interaction treatment between Calmax at a concentration of 4 ml L^-1 and Stimplex at a concentration of 12 ml L^-1 revealed remarkable differences. The highest averages for flavonoids, glutathione, vitamin C, and the superoxide dismutase enzyme emerged at 13.94 mg g^-1, 13.56 μmol g^-1, 1.66 mg g^-1, and 18.45 unit g^-1 f.w., respectively, compared with the control treatment.

Keywords: Date palm (P. dactylifera L.), Calmax, flavonoids, glutathione, Stimplex, vitamin C

Key findings: A significant increase was evident in the leaf content (antioxidants flavonoids, glutathione, vitamin C, and superoxide dismutase enzyme) of the date palm (P. dactylifera L.) cultivar Lulu due to foliar application of Calmax (4 ml L^-1) and Stimplex (12 ml L^-1) and their interaction.

An agriculture experiment materialized during the cropping season of 2022–2023 in the Kateban Area, Basra Governorate, Iraq, to demonstrate the effect of nitrogen fertilization with three levels (0, 100, and 200 kg ha^-1) on two types of cultivars of broad bean plants (Shamea and local) grown in clay loam soil. The study also displayed enhance fertilization by spraying two types of liquid fertilizers (Al-Jamea Fertilizer and Communication) on the beans. Results showed the broad bean cultivar Shamea, the commercial liquid fertilizer, and the level of nitrogen fertilization (200 kg ha^-1) were significantly superior for plant height, plant dry weight, protein percentage, and copper content, except for the iron content. The highest values were 95.20 cm, 50.14 gm, 39.98%, and 39.98 ppm, respectively, from the interaction among the bean cultivar, type of liquid fertilizer, and the level of nitrogen fertilization at 100 kg ha^-1, reaching 0.5637 ppm.

Keywords: Broad bean (Vicia faba L.), cultivars, liquid fertilizer, protein, iron, copper

Key findings: Using the cultivar Shamea with liquid foliar fertilization increased plant growth, including plant height, dry weight of the vegetative part, protein percentage, and plant content of micronutrients (iron and copper), especially when using a nitrogen fertilization level of 200 kg ha^-1.

The study investigates the use of biochar as a soil improver to address various crop cultivation challenges by utilizing actinomycetes to enhance the available nutrients for plants. It aimed to examine the response of cocoa plants to different types of biochar and concentrations of actinomycetes for growth and productivity. This research began in Watu Toa Village, Marioriwawo District, Soppeng Regency, using 3-year-old MCC 02 plants. The research employed a split-plot design with main plots as the types of biochar (rice husk, coconut shell, and corn cob biochars). The subplots comprised various concentrations of actinomycetes, i.e., 0, 30, 60, and 90 mL L^-1. The results revealed significant interaction effects between the types of biochar and actinomycetes concentration on stomatal opening area (83.04 μm²), number of cocoa pods formed (43.11 pods), percentage of fallen flower cluster (32.39%), and 100 dry beans’ weight (171.68 g). However, the individual application of actinomycetes enunciated the most pronounced effects, particularly in the number of pods created (126.52 pods), the percentage of fallen cocoa pods (16.77%), the number of harvested fruits (15.67 fruits), and the production yield (618.84 g/tree and 687.53 kg/ha).

Keywords: Cocoa (T. cacao L.), biochar, actinomycetes, interaction effects, growth and physiological traits, productivity

Key findings: The combination of corn cob biochar and the highest concentration of actinomycetes (90 mL L^-1) provided the best effects on cocoa (T. cacao L.) for the stomatal openings, the lowest percentage of fallen flowers, and the maximum 100 dry seeds’ weight.