Abiotic and biotic stress challenges of Cassava in changing climate and strategies to overcome: A review

Cassava (Manihot esculenta Crantz) is a multi-utility starchy tuber crop with immense economic and industrial potential that are ideal for solving multiple crises including hunger and malnutrition. It is grown throughout tropical Africa, Asia and Americas for producing starch, bioethanol and other bio-based products. However, different abiotic and biotic stresses have been affecting cassava productivity, amidst the threat of changing climate. Here we review various stress challenges encountered by cassava, its response cum defence mechanisms and possible mitigation strategies by pulling together the published information. Our principal findings include -(1) Cassava deploys various biochemical, physiological and molecular strategies including transcription factors, secondary metabolites and phyto-hormone associated defense mechanisms to cope up with various stresses; (2) Understanding stress response mechanisms including plant-pest-pathogen interactions is crucial for effective stress management; (3) Strategic breeding programmes to develop high yielding, stress tolerant varieties, cultivation of location and climate specific cultivars, conventional time tested disease and pest management strategies are suggested to deal with the situation. This is the first comprehensive review on stress challenges of cassava to be useful for researchers, farmers and policy makers to assess stress impact on crop performance and to design relevant strategies to overcome the circumstances.