A Comparative Study of the Effects of Photoperiod on the Growth, Flowering, Yield Attributes and Oil Content of Ten Sesame Genotypes
Abstract
The effect of three photoperiods (8 hr=SD; 13–14 hr=ND and 24 hr=LD) was studied in the case of 10 genotypes of Sesamum indicum. As the photoperiods were prolonged the time required for flowering and the number of leaves and branches increased at the same time fruit setting, seed yield and oil content of seeds decreased. First floral buds appeared in approximately 33, 46 and 62 days; and the first flower opened after 48, 63 and 74 days from sowing under SD, ND and LD conditions respectively. This suggests that sesame is a quantitative short-day plant. No genotype showed complete photo-insensitivity. The number of flower buds increased with increasing photoperiods, associated with a decrease in fruit setting (19 to 47% in SD and 7 to 27% in ND). No fruits were formed under LD. Seed yield and oil percentage increased with shortening photoperiods. Seed yield per plant ranged from 0.118 to 1.946 g in ND and 1.181 to 4.035 g in SD. Higher seed yield was attributed to relatively higher seed size in SD. Mean oil yield was 47.13% in SD and 33.46% in ND. The results show the importance of early flowering for high seed and oil yields.
