Morphological Relationships among Plant Architecture, Yield Components, and Seed Quality of Safflower under different Irrigation Intervals

Expression of Metrical Traits on Yield and its Components in Different Accessions of Soybeans (Glycine max (L.) Merrill)

Low productivity in soybean (Glycine max L. Merrill) across Nigerian farming systems remains a persistent challenge, driven in part by the limited use of genetically diverse and locally adapted cultivars. This study evaluated the expression of yield-related traits among ten soybean accessions obtained from the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria, to identify superior genotypes and inform selection strategies for yield improvement. The experiment was conducted in a Randomized Complete Block Design (RCBD) with three replications at the research farm of Adekunle Ajasin University, Akungba-Akoko, Ondo State, Nigeria. Data were collected on nine quantitative traits: plant height, number of main branches, days to first flowering, days to maturity, pod length, pods per plant, seeds per pod, 100-seed weight, number of seeds per plant, and seed yield per plant. Analysis of variance revealed significant genotypic effects (p ≤ 0.05) for most traits, except for the number of main branches and pods per plant. Accession V9 recorded the highest seed yield per plant (16.14 g), pods per plant (23.80), seeds per pod (3.53), and number of seeds per plant (84.71), while V5 produced the heaviest 100-seed weight (22.27 g). Genetic parameter estimates showed that days to first flowering had the highest broad-sense heritability (92.89%), followed by pod length (72.08%) and seeds per pod (70.58%), all with moderate to high genetic advance. Pearson's correlation analysis revealed highly significant positive associations between seeds per pod and number of seeds per plant (r = 0.93), number of seeds per plant and seed yield per plant (r = 0.87), and seeds per pod and seed yield per plant (r = 0.78). These findings identify V9 as the most promising accession for yield improvement and recommend seeds per pod and number of seeds per plant as the most reliable indirect selection criteria for advancing soybean yield within this germplasm.

Effect of soil water availability on tree growth, yield components and fruit quality of Arbequina, Lecciana and Oliana olive cultivars grown in super-high-density planting systems

Plant population: impacts on vegetative architecture, yield components, and grain yield

Plant population is one of the main management practices influencing soybean development and grain yield, particularly in modern cultivars with high phenotypic plasticity. This study evaluated the effects of different plant populations on yield components and grain yield of the soybean cultivar Brasmax Zeus IPRO under subtropical growing conditions. The experiment was conducted during the 2020/21 growing season in Dois Vizinhos, Paraná, Brazil, using a randomized complete block design with five plant populations (4, 6, 8, 10, and 12 plants m⁻¹) and four replications. Plant height, first pod insertion height, number of reproductive nodes, branches, pods, grains per plant, thousand-grain weight, and grain yield were evaluated. Plant height and thousand-grain weight were not significantly affected by plant population. Conversely, first pod insertion height increased linearly as plant density increased. Reduced plant populations promoted greater branching and significantly increased the number of reproductive nodes, pods, and grains per plant, demonstrating the strong compensatory growth capacity of soybean under low-density conditions. However, these morphological adjustments were insufficient to compensate for the lower number of plants per unit area. Consequently, grain yield increased linearly with plant population, with the highest yield (5,878.3 kg ha⁻¹) obtained at 12 plants m⁻¹, representing an increase of approximately 38% compared with the lowest population. The results demonstrate that although the soybean cultivar Brasmax Zeus IPRO exhibits considerable phenotypic plasticity, maintaining an adequate plant population is essential to maximize grain yield. Under the environmental conditions of this study, a population of 12 plants m⁻¹ (266,666 plants ha⁻¹) was the most suitable for achieving maximum productivity.

Plant Density Effects on Variety Specific of Safflower (Carthamus tinctorius L.)

Safflower (Carthamus tinctorius L.) is a multipurpose oilseed crop with considerable potential for diversification of oilseed production in semi-arid environments. However, productivity depends strongly on genotype and plant population, which influence canopy architecture, biomass accumulation, yield formation, and assimilate partitioning. This study evaluated the effects of three plant densities (128,571, 257,142, and 385,714 plants ha⁻¹) on the growth, yield components, biomass production, harvest index, and seed quality of two safflower varieties, Dongla and Giza, during two winter growing seasons (2014/15 and 2015/16) in Sudan. Field experiments were conducted at Shambat, Khartoum North, Sudan, using a randomised complete block design with three replications based on split-plot arrangements. Analysis of variance was performed separately for each growing season, and combined means were used to assess overall treatment responses. The varieties exhibited contrasting growth architectures. Giza was consistently taller and developed a greater leaf area, whereas Dongla produced substantially more branches and heads per plant. Relative growth rate, plant height, branch number, and leaf area showed considerable numerical variation among treatments, although treatment effects were not statistically significant. Thousand-seed weight was significantly affected by treatment combinations in the first season and in the combined analysis, with the highest overall value recorded for Giza at 257,142 plants ha⁻¹ (27.7 g). Giza generally produced greater biomass, reaching 10.3 t ha⁻¹ at 385,714 plants ha⁻¹, whereas Dongla achieved the highest combined harvest index (15.5%) at 257,142 plants ha⁻¹. Seed yield ranged from 0.9 to 1.4 t ha⁻¹, with the highest combined mean yield (1.2 t ha⁻¹) recorded for Dongla at 257,142 plants ha⁻¹ and Giza at 385,714 plants ha⁻¹. Seed fat, protein, and crude fibre contents remained stable across treatments. Overall, the results demonstrate the importance of variety-specific plant-density management for optimizing safflower growth, biomass production, and assimilate partitioning under varying Sudanese environmental conditions.

How water stress impacts soybean grain yield and quality through canopy and root system adaptation

Soybean is the most widely grown legume species in the world. Nevertheless, the influence of irrigation on the morphological traits associated with grain productivity is not fully understood. In a field experiment, we investigated the effects of irrigation during the vegetative and flowering periods on the root system, canopy structure, grain yield, grain yield components, and grain quality of the soybean cultivar Gallec (MG000, Agroscope), as well as the relationship between these traits. Plants were collected to analyse root systems at R3–R4, biomass allocation within the canopy was analysed at R3–R4, R6–R7, and R7–R8, and the grain yield and grain protein were quantified. Irrigation augmented thousand kernel weight, grain per m 2 and grain protein content and modulated biomass allocation within the canopy and root systems. It also caused a delay in the developmental stages and increased the nodule number and biomass. Different relationships between canopy traits and root traits were observed for rain-fed and irrigated treatments. This suggests that irrigation before pod maturation can sufficiently drive morphological adaptations that could subsequently increase soybean productivity until harvest. Root system adaptation is crucial for optimizing soybean performance following irrigation and should be investigated in future plant breeding or variety evaluation studies.

Genetic Associations and Path Coefficient Analysis of Sesame (Sesamum indicum L.) Yield and Its Components

Fifty-four sesame genotypes, comprising 51 genebank accessions and three farmer-preferred cultivars, were evaluated during the 2023 and 2024 summer seasons at the Kassala and Gash Research Station, Sudan, under surface irrigation using an augmented randomised complete block design. The study assessed phenotypic and genotypic correlations among nine agronomic, phenological, and yield-related traits and identified potential criteria for indirect selection. The traits evaluated were capsule length, number of capsules per plant, number of branches per plant, plant height, height to first capsule, days to 50% flowering, thousand-seed weight, days to maturity, and seed yield. Combined-season analysis revealed that number of capsules per plant had the strongest positive phenotypic (r= 0.745) and genotypic (r= 0.791) correlations with seed yield, followed by number of branches per plant (r= 0.632 and 0.696, respectively) and plant height (r= 0.433 and 0.421, respectively). Capsule length, days to 50% flowering, thousand-seed weight, and days to maturity showed positive associations with seed yield, whereas height to first capsule showed a weak negative association. Path coefficient analysis identified number of capsules per plant as the most important contributor to seed yield, with the largest positive direct effect (0.40) and a substantial total indirect effect (0.34). Number of branches per plant (0.22) and plant height (0.20) also exhibited positive direct effects, whereas height to first capsule and days to maturity showed negative direct effects. These findings indicate that number of capsules per plant and number of branches per plant are important yield-associated traits and promising indirect selection criteria for sesame improvement under Sudanese irrigated conditions. Further multi-environment testing is recommended to validate the stability of these relationships across major sesame-producing environments in Sudan.