In a field investigation with 11 tenera oil palm genotypes a peculiar variation in sex ratio and Fresh Fruit Bunch (FBB) yield was noticed in “Dry” and “Wet” seasons of the year. The dry warm season with bright sunshine was conducive for greater number of female/productive inflorescences and total number of inflorescences. The rainy humid, cloudy and gradually cooling climate from July to December was unfavorable for a desired kind of sex expression. The population mean for sex ratio during dry season over five years was 44 per cent as against 33 per cent in wet rainy season. High female sex ratio during dry season followed by high FFB yield in wet season and low female sex ratio during wet rainy season fallowed by low FFB yield in consecutive dry summer season was the unique feature in oil palm. The genotype OPM-11 showed an uncommon ability to give higher yield in dry season than in wet season.
Dry and wet season, FFB yield, oil palm, sex ratio
