Evaluation of cassava genotypes for hilly areas under rainfed conditions

In Tamil Nadu, India, cassava (Manihot esculenta Crantz) is cultivated under both rainfed and irrigated conditions, primarily for industrial and culinary purposes. Drought poses a significant constraint for cassava cultivation, especially in hilly terrains where water retention is limited. Water scarcity adversely affects cassava growth, leading to reduced leaf area, stunted root development, and ultimately lower yields. Studies have shown that under drought conditions, cassava experiences reductions in leaf water potential, osmotic potential, photosynthesis, and stomatal conductance, all of which contribute to decreased productivity. To address these challenges, high-yielding, high-starch, drought tolerance cassava genotypes (characterized by high relative water content and greater chlorophyll stability index) as well as pest and disease resistant varieties, must be evaluated for their suitability in hilly regions with poor and marginal soils and limited rainfall. The natural resilience of cassava to harsh conditions makes it an essential crop for resources-limited farmers in marginal locations. In Tamil Nadu, the Salem district hosts approximately 800 small-scale sago and starch production facilities. Salem is surrounded by hills where cassava is the primary crop. Farmers face several challenges, such as poor rainfall, low-yielding varieties, pest and disease incidence, and low market prices. Hence, it is very important to evaluate and identify suitable genotypes that can tolerate water deficits, resist disease, yield high, and produce greater starch content. Yield and quality traits have direct impact on economic returns for farmers and determine cassava suitability for various industrial applications. Additionally, plant architecture plays a critical role in enabling cassava to withstand environmental stresses common in hilly areas, such as strong winds and heavy rainfall. This study systematically evaluates these traits, aiming to identify and promote suitable cassava genotypes that can enhance the livelihoods of tribal farmers in hilly regions.