Seed Yield Stability of Okra as Influenced by Planting Date

Fifteen selected okra varieties consisting of ten newly-developed lines and five established varieties were evaluated for stability of seed yields in eight different environments i.e. several monthly plantings for three consecutive years. Seed yield data were analyzed to determine the effectiveness of using different planting dates in seed yield trials of new okra varieties. The wide ranges of environmental indices (- 10.8 to 24.4) and seed yield (2.7 to 38.0 g plant ^-1) indicated significant variation between the environments even though the trials were conducted at the same location. A regression method of stability analysis showed that the mean differences between environments, the varieties and their interactions were highly significant. These results suggest that where limited resources prevent the use of several locations, different dates of planting for two or more years could be used to evaluate okra varieties for seed yield without losing much information on their relative ranking.