The Effects of NPS Fertilizer Rates on Yield and Yield Components of Malt Barley (Hordeum vulgare L.) Varieties in Gitlo, Horro Guduru Wallaga Zone, Ethiopia

Abstract

A field experiment was conducted during the 2022/23 cropping season at Gitlo, Horro District, Horro Guduru Wollega Zone, to evaluate the effects of NPS fertilizer rates on the yield and yield components of malt barley (Hordeum vulgare L.) varieties. The study employed a randomized complete block design in a factorial arrangement with three replications, testing three malt barley varieties (HB1963, Holker, and IBON174/03) under five NPS fertilizer rates (0, 23, 46, 69, and 92 kg ha⁻¹). Significant varietal differences (P < 0.05) were observed for days to 50% heading, number of seeds per spike, and spike weight. The earliest maturing variety was IBON174/03 (112 days), whereas Holker exhibited the longest duration to 50% heading (78 days). Application of NPS fertilizer significantly increased the number of seeds per spike, with the highest value (33 seeds) recorded at 92 kg ha⁻¹. The interaction between varieties and NPS fertilizer rates significantly influenced days to maturity, plant height, and yield components. HB1963 achieved the tallest plant height (95.8 cm) at 92 kg ha⁻¹ NPS, while Holker produced the highest grain yield (5429 kg ha⁻¹) at the same fertilizer rate, indicating a strong positive response to increased nutrient input. These findings suggest that malt barley productivity in the study area can be enhanced by combining the Holker variety with 92 kg NPS ha⁻¹; however, further multi-season and multi-location studies are recommended to validate these results and to develop region-specific fertilizer and variety recommendations.