EFFECT OF NITROGEN RATE ON GRAIN YIELD OF BREAD WHEAT GENOTYPES

Gorjanovic B., M. Zoric, and M. Kraljevic Balalic (2010): Effect of nitrogen rate on grain yield of bread wheat genotypes. - Genetika, Vol 42, No. 2, 279 -286. The improvement in grain yield is the main objective of bread wheat breeding programs. Numerous studies indicate that nitrogen is the key factor of yield and quality in the wheat. The goal of this paper is to investigate variability of grain yield, of twelve bread wheat genotypes, on three nitrogen level. ANOVA showed that this trait was mostly under influence of the genotype (36, 3%), year x genotype interaction (26, 3%), year of investigation (14, 1%), and in the smallest amount of the nitrogen rate (8, 8%). On all three nitrogen level, the highest grain yield was found in the variety Malyska. The lowest grain yield in control was found in the variety Nevesinjka, while in the N75 and N100 rates it was found in the variety Tamaro. The mean performance of individual cultivars, in nine environments (three years x three nitrogen rates), was depicted using which-won-were view of SREG2 biplot. The nine environments fall into two sectors, which is an indication of a strong crossover GE interaction. Genotype Malyska was the winner (the highest yielding variety) in first sector containing seven environments, while genotypes Pertrana and Axis were the winners in second sector containing two environments.