Influence of sowing date on fruit yield of okra varieties

A field experiment was conducted at the Instructional Farm, College of Agriculture, Vellayani, Kerala, from October 2024 to May 2025 to determine the optimum sowing date and suitable variety for maximizing yield of okra. The study evaluated five sowing dates viz., 01 October 2024, 01 November 2024, 01 December 2024, 01 January 2025, and 01 February 2025, and three varieties viz., Anjitha, Aruna, and Arka Anamika, in a split-plot design. Results revealed that sowing date and varietal choice exert a significant and interactive influence on crop duration, growing degree days (GDD), leaf area index (LAI), and yield performance of okra. Among the five sowing dates, February and January provided the most favourable thermal and environmental conditions, resulting in superior growth and yield attributes. February sowing recorded the highest LAI (2.28), dry matter accumulation (63.58 g plant^-1), fruit weight (20.48 g), and fruit yield (404.85 g plant^-1), all of which were statistically comparable with January. In contrast, December sowing resulted in the lowest performance, reflected in shortest crop duration (94 days), and lowest GDD accumulation (1620 °C·days). Among the varieties, Arka Anamika was the most productive, recording the highest values for crop duration (102 days), GDD (1762 °C·days), LAI (2.15), dry matter (57.96 g plant^-1), fruits per plant (19.29), fruit weight (19.74 g), and fruit yield (394.49 g plant^-1). The Arka Anamika × February interaction exhibited superior performance, characterised by maximum GDD (1808 °C·days), LAI (2.45), dry matter (71.49 g plant^-1), fruit weight (21.43 g), and fruit yield (479.49 g plant^-1), confirming its thermal responsiveness. Correlation analysis further revealed that fruit yield had strong positive associations with dry matter (r = 0.97), fruit weight (r = 0.97), number of fruits per plant (r = 0.96), and LAI (r = 0.88), while showing moderate correlation with GDD (r = 0.53). These results underscore the central role of canopy development, biomass accumulation, and assimilate partitioning in yield expression. The study concluded that sowing okra, particularly the variety Arka Anamika during January or February provides the most favourable thermal environment, thereby maximizing vegetative growth, higher biomass accumulation, and improved fruit yield under the agroclimatic conditions in Southern Laterites of Kerala.