Drought stress on yield performances of three mung bean (Vigna radiata (L.)Wilczek) varieties in Sri Lanka

Abstract

Mung bean (Vigna radiata) is a tropical pulse crop mainly cultivated in the dry zone of Sri Lanka which faced frequent drought stresses. Drought can be affected to the quality and quantity of the yield. Therefore, this study was carried out to identify the critical growth stages of the plant that can be affected to the yield and to select the most suitable drought tolerant variety. The study was carried out as pot experiments using a Mung bean variety, ARI, MI 5 and MI 6 imposing drought at vegetative, flowering and pod filling stages. Plants were watered up to the field capacity at three days interval in control treatment. The experiment was arranged in a Completely Randomized design (CRD) with five replicates. Mean number and weight (g) of pods, grains per pod, shrink grains per pod, number of discolored grains per pod, pigmented stem height at 2 weeks and 3 weeks after sawing and the germination percentages of seeds from different treatments were recorded. The results revealed that moisture stress was significantly reduced (P<0.05) the mean number and weight (g) of pods while number and weight of shrink grains per pod was increased. Number of grains per pod was not affected. Variety MI 5 produced least number and weight of shrink grains per pod. The highest number of grains per pod was recorded in variety MI 5 and MI 6. There is no significant effect of variety and stage of drought stress imposed on number of discolored seeds per pod, weight of grains per pod and for germination of seeds from different treatments. Hence variety MI 5 can be considered as most suitable drought tolerant variety among tested varieties.