Growth and Yield Performance of Two Contrasting Mung Bean Varieties Under Varying Plant Population Densities

Mung bean is a promising crop in Egypt, but the small seed size (≤ 4 g) of high-yielding varieties like Kawmy-1 limits its widespread adoption. Larger-seeded varieties with higher yield potential, such as VC1973 A (100-seeds > 4 g), are preferred by farmers. However, the impact of plant population densities on growth and yield of these contrasting varieties has not been well studied. This research was conducted during the 2023 and 2024 in summer seasons, aimed to evaluate the effects of varying plant population densities (75, 150, 225, and 300 thousand plants per fed, equivalent to 4200 m2) on the growth, yield, and physiological responses of two mung bean varieties, Kawmy-1 and VC1973 A, under biological stress. The results revealed that Kawmy-1 exhibited tolerance to high-density stress (300,000 plants per fed), maintaining favorable growth and yield, while VC1973 A showed superior vegetative growth across parameters such as dry matter accumulation, leaf area, and leaf weight ratio. In contrast, Kawmy-1 excelled in attributes like leaf area ratio, specific leaf area, relative growth rate, and net assimilation rate. Increased plant density significantly reduced several growth parameters, but some traits like leaf area index, leaf area ratio, and leaf weight ratio showed reversible trends. In terms of yield, Kawmy-1 outperformed VC1973 A in pod and seed yield plant－1, while VC1973 A achieved better plant height and 100-seed weight. Interestingly, higher plant densities enhanced protein content but decreased overall yield and carbohydrate levels. This study underscores the importance of optimizing plant population density to balance yield and quality in mung bean cultivation. Future research should explore the genetic potential of larger-seeded varieties like VC1973 A, as well as strategies to enhance their performance under varying agronomic conditions.