Phenological and yield characteristics of sesame (Sesamum indicum L.) as affected by nitrogen and phosphorous rates in Mubi, Northern Guinea Savanna Ecological Zone of Nigeria

Field experiments were conducted during the 2005 and 2006 cropping seasons at the Teaching and Research Farm of Adamawa State University, Mubi, Nigeria (10^0 15’ N, 13^0 16’ E and 696 m above sea level) to study the effect of nitrogen (N) and phosphorous (P) rates on some phenological and yield characteristics of sesame. The treatments consisted of four N rates: 0, 30, 60 and 90 kg ha^-1 and four P rates: 0, 15, 30 and 45 kg ha^-1. These treatments in factorial combinations were laid out in split plot design with N rates assigned to main plots and P rates assigned to sub plots and were replicated four times. The following data were collected on phenological and yield characteristics: days to 50 % flowering, days to 50 % maturity, weight of biomass at eight weeks after sowing (WAS) and at harvest, dry weight of leaves at 8 WAS and at harvest, number of pods per plant and total seed yield. Results showed significant (P 0.05) effect on all characteristics, except number of leaves at 8 WAS and days to 50 % maturity in both cropping seasons. Similarly, there were significant effects of N rates on dry weight of leaves, weight of biomass at harvest and number of pods per plant up to a maximum of 90 kg N ha^-1. P rates showed no significant effect on all characteristics measured. There was an interaction between cropping seasons and N rates on weight of biomass at 8 WAS and number of pods per plant. It was therefore concluded that application of N had a significant effect (P 0.05) on some yield characteristics of sesame in Mubi. P rates up to 45 kg ha^-1 however, had no significant (P 0.05) effect on phenological and yield characteristics. Further research needs to be conducted on N and P rates above 90 and 45 kg ha^-1, respectively, to ascertain effects of optimum rates of N and P on sesame phenological and yield characteristics. In addition, the method of P application in the form of side dressing 2 to 3 WAS should be considered for possible effects.