Enhancing Soybean Productivity through Cobalt and Molybdenum: Seed Priming Versus Foliar Application

Abstract

Micronutrients, although required in small quantities, play critical roles in legume physiology and biological nitrogen fixation (BNF), making their management critical in soybean production systems. This study was conducted during the 2024 and 2025 seasons to evaluate the effects of cobalt (Co) and molybdenum (Mo), applied through seed priming and foliar spraying, on the growth, yield, and seed quality of three soybean (Glycine max L.)  genotypes (H18L54, Masry 10, and Giza 111). A factorial experiment was arranged in a randomised complete block design (RCBD) with three replicates under field conditions, while laboratory experiments followed a completely randomised design with four replicates. Data were analysed using analysis of variance (ANOVA), and means were compared using the revised least significant difference (RLSD) test at a 5% probability level. Results indicated that plant height, 100-seed weight, number of pods, oil content, seed yield, and flowering time were significantly affected by treatments and genotypes, whereas their interaction was mostly non-significant under field conditions. Giza 111 exhibited superior performance in plant height of 103.3 cm and the highest seed yield of 2571.1 kg/fed. In contrast, Masry 10 recorded the highest 100-seed weight at 18.5 g. reflecting significant genotypic variation. Cobalt seed priming was the most effective treatment, significantly enhancing germination rate, seedling vigour, shoot length, and seedling biomass, with notable interaction effects under laboratory conditions. Molybdenum treatments showed moderate effects, whereas foliar applications were generally less effective than seed priming. Overall, cobalt and molybdenum applications, particularly through seed priming, can be considered an effective strategy to improve soybean productivity and seed quality by enhancing nitrogen metabolism and early seedling performance.