Effect of Nitrogen Rates on Yield, Yield attributing traits and Quality of Recently Released Durum Wheat Varieties in Bale Highlands of Ethiopia

Proper rate of fertilizer application is the major factor that hinders yield and quality of durum wheat production. Site specific fertilizer recommendation is not done in study area. This Research activity was conducted at Sinana and Gololcha districts of East Bale and Bale zone for three years (2016-2018), to assess the effect of nitrogen fertilizer rate on yield, yield attributing traits and grain quality of durum wheat varieties. Factorial combinations of four durum wheat varieties (Toltu, Dire, Bekelcha and Ingliz ) and five rates of nitrogen (46,92,138,184 and 230 kg N ha-1) were laid out in a randomized complete block design (RCBD) with three replications. The main effects of nitrogen and variety significantly (P < 0.05) influenced plant height, spike length, kernels per spike, biomass yield, grain yield, harvest index ,TKW, HLW and grain protein content. Variety Diredurum wheat variety recorded the highest grain yield (4650 kg ha-1) in statistical parity with Bekelcha (4563 kg ha-1). The lowest yield was obtained from local variety Ingliz (3653 kg ha-1). Combined analysis of the results revealed that grain yield was significantly affected by main effects of varieties and N fertilizer rates. The .highest N rate (230kg N ha-1) recorded the highest grain yield (4536 kg ha-1). The lowest yield (3815 kg ha-1) was recorded by the lowest N rate (46 kg N ha-1).Bekelcha variety gave the highest grain protein content(14.6%). The lowest grain protein content (12.9g) was recorded from local variety Ingliz. The highest grain protein content (15.1%) was obtained from the application of the highest N rate (230kg N ha-1), the lowest (12.8%) was from the lowest N rate (46kg N ha-1).The economic analysis indicated that optimum grain yield and quality of the improved durum wheat varieties by application of 92 kg ha-1 Nitrogen fertilizers.