Drought Stress Tolerance in Legume Crops

The environment is defined as the sum total of all biotic and abiotic factors other than individual concerned. The various factors are called biotic and abiotic depending upon their biological and non-biological nature. When some environmental factors interfere with complete expression of cultivars/varieties potential, they are known as stress. Stress is categorized into two types: (a) biotic stress that includes pathogen, pests, weeds, etc., and (b) abiotic stress due to moisture (excess/deficit), temperature (high/low), minerals (deficiency/toxicity), salinity, soil pH, air pollution, etc. Drought, which is a major and most important abiotic stress, acts as a constraint to productivity of legumes. It is a meteorological phenomenon which implicit the lack of rainfall for a long period of time which caused moisture reduction in soil and water shortage with a deficiency of water potential in plant tissues. It inhibits the crop from achieving the potential yield and severely lowers the legume production. Generally, grain legumes depend on rainfall and are susceptible to irregular drought stress throughout its vegetative and reproductive growth phase. During pod filling stage, drought stress is very common in legume crops and reduced yield in the crops grown with current rainfall. It can be minimized by developing cultivars tolerant to drought stress.