Growth and root system distribution in peanut, sesame and castorbean under water defi cit cycles

Abstract

A greenhouse study was carried out with the objectives of studying the shoot and root growth, and root stratification in the soil profile for peanut, sesame and castor bean, grown under several cycles of water stress. Peanut plants had the smallest dry matter partition to the roots, followed by sesame (intermediary position) and finally by castor bean which partitioned the higher proportion of dry matter to the roots. Total dry matter was reduced in the three crops studied in response to water stress. Root/shoot ratio increased in response to water stress in sesame and peanut, while in castor bean this relationship remained unchanged. Peanut showed the greatest deepening of the root system in the soil profile in response to water stress. Castor bean had the smallest response as far as deepening of the root system is concerned, and sesame stayed at an intermediary position. The leaf number and leaf area were reduced in the three species in response to water stress.