Effect of nitrogen fertilizer timing and source on some yield and quality parameters of durum wheat (Triticum durum)

As the energetic cost of synthesizing nitrogen (N) fertilizers is very high, management of N fertilizer is important for reducing costs and soil pollution, while increasing grain yield and quality. N fertilizing (form, application timing, dosage and source) has important effect on the quality of wheat. In this study, a field experiment was designed to study the effects of application type (timing and source) of N fertilizer on grain yield and quality in durum wheat (Altar-84, Gediz-75, Ege-88, Ki{dotless}zi{dotless}ltan-91, and Kunduru-1149). The experiments were conducted in split plot arrangement with four replications in Bornova and Menemen locations during two growing seasons. In all the plots, single rate of 16 kg/da N fertilizer was applied with different application timing (stem elongation and heading stages) and sources (ammonium nitrate and urea). Results from analyses of variance indicate that there were significant differences among cultivars in all studied characteristics (grain yield, 1000-kernel weight, test weight, grain protein content, SDS-sedimentation) in all environments. Effect of N fertilizer application type on yield, 1000-kernel weight, test weight, grain protein content and SDS-sedimentation, varies depending on year and location. It was found that Ege-88 had the highest grain yield and 1000-kernel weight and Kunduru-1149 had the highest protein content and SDS-sedimentation potential in compare to other cultivars. By considering the mean values for all locations and years, it can be understood that application of N fertilizer as foliar urea led to increase in protein content of all cultivars except for Altar-84, while application of ammonium nitrate only led to increase in protein content of Kunduru-1149 cultivar over all locations and years