The quest for high yielding drought-tolerant cassava variety

Abstract

This study was planned to assess the morpho-physiological response of cassava varieties under well-watered and water-deficit stress conditions along with the exploration of potential yield attributing traits that could facilitate in achieving higher productivity under water stress conditions. Scrutiny of the data revealed that all the traits under study viz; plant height, leaf area index, the number of leaves and leaf retention index reduced significantly (P<0.05) due to less water availability. Physiological parameters were also affected severely due to the central role of stomatal activity under water stress. Photosynthetic efficiency of plants subjected to water stress was about ½ fold of the plants grown under well-watered condition. Detailed investigation of various traits revealed that the variety which maintained higher photosynthetic activities along with the higher number of leaves, leaf area index, leaf retention index and harvest index produced a higher yield under water-deficient environment. Hence we are of the strong opinion that these traits are the drivers of higher productivity under water stress environments. Involvement of these traits in the breeding programme would lead to the breeding of a drought-tolerant cassava variety.