Grain Quality and Yield Response of Malt Barley Varieties to Nitrogen Fertilizer Rates in the West Arsi, Oromia Reginal State of Ethiopia

Abstract

Grain yield and yield components of malt barley (<i>Hordeum vulgare</i> L.) were investigated concerning varieties and nitrogen application rates. A field experiment was conducted to evaluate (i) the optimal fertilizer level for maximum yield and quality of malt barley varieties (ii) to determine the impacts of nitrogen fertilizer rate, vaieties and growing season on yield and yield components of malt barley. Three malt barley varieties (Ibon, Bekoji 1, and EH1847) and four fertilizer rates (RNP kg ha<sup>-1</sup>, 150% RNP kg ha<sup>-1</sup>, 200% RNP kg ha<sup>-1</sup> and RNPS kg ha<sup>-1</sup>) were studied over two growing season (2019 and 2020) in a factorial arrangement of randomized complete block design (RCBD) and replicated three times. The main effects of<sup>-</sup> variety and fertilizer rate were significantly (P<0.01) variation, on grain yield, biomass yield, hectolitre weight and thousand kernel weight, while plant height, spike length and grain protein content showed significant (P<0.05) variations. The interaction effect of variety and fertilizer rate on the number of grains per spike indicated significant (P<0.001) variation. The use of a 200% RNP kg ha<sup>-1</sup> fertilizer rate resulted in a higher (4152.9 kg ha<sup>-1</sup>) grain yield. The highest (33.1) number of grain per spike was produced from the combination of 150% RNP kg ha<sup>-1</sup> fertilizer rate with Bekoji 1 malt barley variety, Like wise higher (48.6) thousand kernel weight was produced from RNPS. The results of this study indicated that, the importance of using appropriate malt barley variety and fertilizer rate to increase the yield of malt barley with acceptable grain quality in the study area. Hence application of 150% RNP and 200% RNP kg ha<sup>-1</sup> gave a grain yield of (3582.81 kg ha<sup>-1</sup>) and (4152.9 kg ha<sup>-1</sup>, and economic benefit of 5.99 (ETB) and 3.65 (ETB) respectively. Among malt barley varieties highest (4110.4) and (3538.3) kg ha<sup>-1</sup> grain yield was recorded from EH1847 and Bekoji 1 verities respectively. The production of malt barley with higher yield, optimal kernel protein concentration and higher economic benefit was obtained via EH1847 malt barley varieties along with 150% RNP and 200% kg ha<sup>-1</sup> fertilizer rate in the study area and similar agro ecologies.