ISSN 2360-7971
Abstract: A decline in soil fertility and a lack of site-specific fertilizer recommendations are among the main factors contributing to the low productivity of wheat in Ethiopia in general and Waliso in particular. A field experiment was carried out during the 2022 cropping season at Woliso District to determine the effect of nitrogen rates on growth, grain yield, and yield components of bread wheat (Triticum aestivum L.) varieties at Woliso district, central Ethiopia. The treatments consisted of five nitrogen rates (0, 23, 46, 69, and 92 kg ha-1) and three varieties. The experiment was laid out in a 3*5 factorially arranged in a randomised complete block design with three replications. Data on growth, yield, and its components were recorded and subjected to analysis of variance (ANOVA) using SAS version 9.3. The results of the analysis of variance showed that N and variety had main effects and interaction effects on leaf area, number of productive tillers per plant, number of spike length, thousand-grain weight, dry biomass yield, straw yield, and grain yield (all with P ≤ 0.05). However, days to 50% heading, days to 90% physiological maturity, plant height, spikelets per spike, grain per spike, and harvest index were only affected (P ≤ 0.05) by the main effects of N rates and varieties. Almost all yield parameters went down as the nitrogen rates went up, except for thousand-grain weight and agronomic efficiency. This happened up to 92 kg N ha-1. Combining the Wane variety with 92 kg N ha-1 yielded a higher grain yield of 4307.96 kg ha-1, and this combination was also economically feasible. Days to heading (r = 0.86**), days to physiological maturity (r = 0.64**), plant height (r = 0.93**), leaf area (r = 0.92**), and spike length (r = 0.95**) were significant (P < 0.01) and positively correlated with grain yield. The correlation between grain yield and productive tillers (r = 0.98**), the number of seeds per spike (r = 0.97**), the grain per spike (r = 0.96**), biomass yields (r = 0.98**), and the thousand-grain weight (r = -0.45**) was significant and positive. The combination of 92 kg N ha-1 with Wane variety yielded the highest net benefits (109,551.04) and marginal rate of return (2753.41). Therefore, we found that applying 92 kg N ha-1 fertiliser rates with the Wane variety was both agronomically and economically feasible for bread wheat production in the study area.
Keywords: bread wheat, growth, grain yield, nitrogen fertilizer