Effect of Water Stress on Growth and Yield of Mung Bean (Vigna radiata L)

Abstract

Legumes are second only to the Graminae in their importance to humans. Mung bean ( Vigna radiata L) is one of the most important grain legumes cultivated in Sri Lanka. Drought is a major abiotic stress on Mung bean in the sub-humid, dry and intermediate zones of Sri Lanka. The present reveals the response of Mung bean for the water stress at three different growth stages; three weeks after planting (3WAP), six weeks after planting (6WAP) and eight weeks after planting (8WAP). A pot experiment was carried out at Faculty of Agriculture, University of Ruhuna, Mapalana, Sri Lanka. Plant height, number of leaves, number of floral buds dry matter weight of shoot system, number of lateral roots, length of tap root, number of root nodules, and dry matter weight of root system were measured after one week recovery period in stressed plants at three different growth stages and in relevant control plants. Water stress significantly affects on each measured parameter at 6WAP when the flowering and pod filling stage of Mung bean and only number of leaves was significantly affected at the 8 WAP. Further, all the measured parameters were significantly affected at 3WAP under drought stress other than length of tap root and number of nodules per plant. Number of floral buds and number of pods were not affected by the drought stress at 8WAP though there is no economical value of these characters as the pod filling efficiency is low in Mung bean under drought stress.