Nonparametric approach to multitrait selection for yield in groundnut (Arachis hypogaea L.).

Eight characters related to nitrogen fixation and pod development measured 30 days after flowering were evaluated for their correct grading of the relative yield performance of 17 genetically diverse lines of groundnut (Arachis hypogaea L.). Each line was assigned a high or low yield status based on its pod yield, shelling percentage, and 100-kernel weight. Seventeen character combinations were examined for their relative merit in correct identification of the yield status of lines. The character sets, nitrogenase activity alone or in combination with nitrogen percent or shoot weight identified the status of 77% of lines correctly. The extent to which various characters accounted for the variation in pod yield was also checked by multiple regression analysis. While the character combination, nitrogen percent plus leaf area explained 75% of variation in pod yield, nodule mass, nitrogenase activity, and leaf area occurred in some other combinations that explained yield variation to a lesser extent. These analyses point to the profitability of involving crop physiological traits such as leaf area and nitrogen percent in selecting for relative yield performance in groundnut.