DROUGHT STRESS IN NEPAL: IMPACT ON WHEAT AND STRATEGIES FOR MANAGEMENT-A REVIEW
ABSTRACT
Wheat, a crucial cereal crop, serves over 2.5 billion people globally, with Asia contributing 36.25% of its projected global yield in 2020. In Nepal, it ranks third in cultivation land and productivity, with land covering 716,978 hectares and 2,144,568 metric tons production, with Madesh province having the highest producing province producing 628,909 metric tons in 2078/79. Abiotic stresses, along with global climate change, are the primary factors that restrict global wheat production. The eastern and central regions of Nepal are more prone to drought conditions, owing to water scarcity. Variation in precipitation and temperature over time leads to annual and seasonal drought, causing yield decline, leading to a lower GDP of livelihood. Drought stress affects all plant parts, including the morphology, physiology, and biochemistry of wheat plants. Germination rate, plant turgor, leaf area, nutrient and water assimilation, and various other aspects are affected by drought. At the physiological level, decreased photochemical efficiency, increased production of Reactive Oxygen Species (ROS), enhanced proline production, and decreased starch accumulation are conditions caused by drought stress in wheat. To solve the problem of drought, interdisciplinary approaches such as plant breeding, agronomy, plant physiology, and water engineering have been developed. Water management, nutrient management, soil health, sowing time, and seed priming are major activities related to agronomy for drought stress management. In addition to agronomic methods, the selection of drought-tolerant varieties, transgenic approaches, QTL mapping, and breeding techniques are equally important for drought management in wheat to sustain productivity and improve the AGDP of Nepal.