Fertilizer N effects on yield and grain quality of durum wheat 146

Gashawbeza, Bemnet; Yaekob, Ameha; Zemede, Alemayehu; Kifetew, Jamanesh; Tadesse, Takalign; Mekuria, Bekele

Five durum wheat (Triticum turgidum L. var. durum) varieties were evaluated for grain yield (GY), vitreous kernels count (VKC), grain protein content (GP), 1000-kernel weight (TKW), and test weight (TW) at two locations (Akaki and Debre Zeit) under five N levels (0, 30, 60, 90. and 120 kg ha-1). Significant differences between varieties and N levels were observed for grain yield at both locations. At Akaki, N fertilization resulted in a significantly linear response with GY advantages of 26.4, 45.5, 52.2, and 56.2% over the control for the respective applications of 30, 60, 90, and 120 kg ha-1. At Debre Zeit, the highest N level, 120 kg N ha-1, gave significantly higher GP than the other treatments, followed by 30 and 0 kg N ha-1 treatments; however, no significant difference was observed between 60, 90, and 120 kg N ha-1 treatments. The effect of fertilizer levels was location-specific for all grain quality traits except TKW, while VKC, GP, and TW were affected by N levels only at Debre Zeit. With regard to varieties, Tob 66 gave the highest VKC, while for GP all varieties except Foka were significantly higher than Kilinto. A significant and positive correlation was also observed between VKC and GP (r = 0.519, P < 0.01). It appeared that selection of appropriate location, variety, and management practices are necessary for the production of high quality durum wheat.