Drought and Heat Stress in Cotton (Gossypium hirsutum L.): Consequences and Their Possible Mitigation Strategies

Abstract

Drought and heat are the most important abiotic stresses that adversely affect phenology, growth, fiber yield, as well as the quality of cotton across the world. The problem will become more severe in future climate change scenarios because of the frequent occurrence of high temperatures and water shortage. Development of high yielding cotton genotypes, resistant to drought and heat stress, is one of the most important priorities of cotton breeders. Therefore, it is important to evaluate the genotypic performance for heat and drought stress and also important to understand the physiological, biochemical responses to stresses as well as the agronomic performance of the genotypes under stress conditions. The correlation between yield and physiological as well as biochemical (nonenzymatic antioxidants and enzymatic antioxidants) responses of cotton under heat and drought stress conditions is also the most important factor to develop the efficient genotypes that are possible to grow. Whereas, screening of cotton genotypes under heat and drought stress is one of the essential protocols that can be used to select a large number of population within the shortest period. This approach can be used to differentiate the agronomical, physiological, and biochemical attributes of cotton genotypes contrasting for drought and heat stress tolerance. The present review tried to highlight the management strategies that could be useful to mitigate the drought and heat stress by using antioxidant, phytohormone, nutrient management, and other appropriate management strategies for maximizing cotton yield. While, among the compatible antioxidants, exogenous application of proline or glycine betaine is a good option to improve drought and heat tolerance in cotton. Therefore, foliar application of antioxidants in combination with soil-applied organic fertilizers is very effective for reducing the negative effect of drought and heat stress and to increase productivity.