Effect of seeding rate and nitrogen fertilizer on wheat grain yield in marginal areas of eastern Kenya

Abstract

This study determined the effect of seeding rate and nitrogen fertilizer on performance of four wheat varieties Ngamia, Duma, NBW1, and Chozi at KARI- Katumani, Eastern province of Kenya in two seasons, 2005 and 2006. The experiment was laid out in a 4x3x4 factorial split-plot in an RCBD replicated four times. Seeding rates (SR) of 75, 100 and 125 kg/ha and nitrogen (N) rates of 0, 12, 23 and 46 kg N/ha were tested. There were variety differences in grain yield (GY), Cultivar Duma had significantly highest GY in 2005 and 2006, respectively. Increasing SR significantly increased plants/m2, tillers/m2, and spikes in cultivar Chozi.. There were significant yield differences due to SR, 125 kg/ ha gave highest GY of 1150.3 and 1175.7 kg/ ha compared to, 75 kg/ ha SR which gave lowest GY of 1018.7 and 1033.6 kg/ha in 2005 and 2006, respectively . N application increased the number of tillers/m2; spikes/m2 and grain yield. The highest N rate of 46 kg/ ha gave the highest GY of 1176.7 and 1200.9 kg/ha compared to the control (0 N) yield of 1022.9 and 1039.7 kg/ ha in 2005 and 2006, respectively. No significant variety x SR, variety x N and N x SR interactions were detected. The study showed that application of N at 46 kg ha -1 at the time of planting is beneficial to wheat crop. SR of 100 kg/ ha is appropriate to save on seed cost as there was no significant difference in GY between 100 and 125 kg/ha SR at Katumani. Wheat is a newly introduced crop in these areas and these results will benefit farmers as they diversify their crops to improve their incomes, food security and raise their living standards.