Responses to Water Deficit of Mung Bean Cultivars at the Vegetative and Flowering Stages under Greenhouse Conditions

Abstract

Mung bean (Vigna radiata L. Wilczek) is grown mainly under rainfed conditions, facing water deficits in different growth stages. This study was conducted to evaluate the responses of a local cultivar, Dau tam Thanh Hoa, and three introduced mung bean cultivars (DX14, Mongo Labo, and TV06425) to water stress at the different growth stages. The experiment was carried out in a greenhouse following a completely randomized arrangement with two replications. Drought was induced by withholding water at either the vegetative or flowering growth stages for 20 consecutive days. The control consisted of well-watered plants. After 8, 12, 15, and 20 days of drought, plant available water, growth characteristics, and the weights of fresh stems and roots were measured. After 20 days of drought, plants were watered to assess their recovery after 7 days and the growth characteristics, weights of fresh stems and roots, and yield components at the harvest stage were evaluated. The results showed that drought affected the growth, resilience, and yield-related factors more severely at the vegetative stage than at the flowering stage. The longer drought was imposed, the greater decline in plant growth was observed. Despite the recovery, fresh root mass and root length were still 40-50% and 10-30% worse than the control, respectively. Based on the growth responses and individual yields, Dau tam Thanh Hoa and DX14 were more tolerant to water deficit and can be used as materials for improving the drought tolerance of mung bean.