ASSESSMENT OF GROUNDNUT CULTIVARS FOR END-OF-SEASON DROUGHT TOLERANCEIN A SAHELIAN ENVIRONMENT

A 2-year study (1990 and 1991) was conducted at the ICRISAT (Internati onal Crops Research Institute for the Semi-Arid Tropics) Sahelian Cent re, near Niamey, Niger, to select groundnut cultivars tolerant to drou ght and to examine selection techniques. Thirty-six cultivars known to vary in yield potential were grown under rainfed and irrigated condit ions. Crop growth rate (C) and partitioning co-efficient (p) were esti mated from phenological and final harvest data. The correlation betwee n years was greater for partitioning than for pod yield (implying a hi gher heritability for p than for yield). Tolerance as determined by a drought susceptibility index for pod yield (S-Y), crop growth rate (S- C) and partitioning (S-p) to reproductive sinks showed thirteen cultiv ars as drought tolerant for either C or p or for both. The Sahelian cu ltivars 796, 55-437 and TS 32-1 were the most consistent for drought t olerance. Partitioning was the most important yield component affectin g yield variation among cultivars.