Effect of Drought & Irrigated Environmental Condition on Yield & Yield Attributing Characteristic of Bread Wheat-a Review

Wheat is one in all the most necessary cereal crops of the world having multiple uses of its own. However, its production is severely restricted by drought up to 60% reduction in the yield. The production of Reactive Oxygen species (ROS), Degradation of photosynthetic apparatus, thereby reducing the photosynthetic Carbon metabolism, declining net CO2 assimilation rate (NAR) & ultimately reducing dry matter accumulation is the cause & effect of reduced mean yield under drought condition. Lack of breeding for drought adaptive traits is leading to low productivity of wheat of 2.85t/ha in Nepal. Climate change leading to global warming & Drought is the major threat to most of agricultural crops grown in tropical & subtropical areas including wheat that causes significant losses by altering the physiological, biochemical & morphological traits of wheat genotypes. It is very important for us to adapt our genotypes to drought stress environment for better nutritional & dietary security of mankind. It is very challenging task for researchers to develop such drought tolerant high yielding variety, more research are needed. Scientists have been working for drought adaptive traits to minimize loss caused by drought to maintain high productivity & production to achieve the goal of zero hunger & malnutrition.