THE EFFECTS OF THE LEVEL AND TIMING OF NITROGEN FERTILİZATION ON THE GRAIN YIELD AND QUALITY OF IRRIGATED WINTER DURUM WHEAT

Abstract

To improve grain yield and quality of irrigated winter durum wheat (Triticum durum L. cv. Kızıltan-91), this study was conducted to determine the optimal amount and timing of nitrogen fertilization. Experiments were carried out in 1997-98 and 1998-99 growing seasons with irrigated winter durum wheat in Konya Region, Central Anatolia, Turkey. The amounts of nitrogen were 50, 100, 150 and 200 kg N ha^-1 versus control. Timings of nitrogen were “the all at sowing”, “1/2 at sowing + 1/2 at stem elongation”, and “1/3 at sowing + 1/3 at stem elongation + 1/3 at boot stage”.

The highest grain yield was obtained with the applications of 150 kg N ha^-1 increasing from 3490 and 3060 kg. ha^-1 to 4540 and 4150 kg. ha^-1 in 1997-98 and 1998-99 seasons, respectively (P<0.01). Split applications of nitrogen increased the grain yield over the single application, the all at sowing. Grain yield for the two seasons were 4380 and 4050 kg ha^-1 in the third application timing while it was 3870 and 3600 kg ha^-1 in the first application timing (all at sowing), respectively (P<0.01). Protein concentration was increased (3 %) by nitrogen application. Split application of nitrogen increased (1 %) protein concentration over single application.