EFFECT OF POPULATION DIVERSITY ON YIELD STABILITY OF SPANISH GROUNDNUT (ARACHIS-HYPOGAEA SUBSP FASTIGIATA VAR VULGARIS)

A study was conducted during summer 1987, rainy season 1987, and winter and summer 1987-88 at 2 locations to compare the yield stability of a heterogeneous population of 'AK 12-24' spanish groundnut (Arachis hypogaea L. subsp fastigiata Waldron var vulgaris Harz.) with that of its 9 component lines, viz 'BGS 1', 'BGS 2', 'BGS 3', 'BGS 4', 'BGS 5', 'BGS 6', 'BGS 7', 'BGS 8', and 'BGS 9'. These 9 varieties of purelines were isolated from the farmers' bulk population 'AK 12-24' by pureline selection method. Besides, another heterogeneous population was synthesized by mixing all the 9 purelines in equal proportion and included in the study. The mix population showed up to 17% increase in pod yield compared with the mean yield of some of its component lines. The population x environment interaction was highly significant for pod yield, indicating the differential response of the populations at different environments. The difference in stability of the mix population and their component lines was recorded. However, no consistent predictable pattern was apparent for the mean and stability values. Some of the component pure lines were more stable than either of their base or mix populations.