Results of the experiments with three wheat cvs (K 7410, K 816 and K 8027), grown at 5 levels of N (0, 40, 80, 120 and 160 kg/ha), revealed that K 7410 was most responsive in both experimental seasons (1991–92 and 1992–1993) while K 816 behaved differently in two experimental seasons. Likewise fertilizer-N utilization also varied with the season. Contrary to these, productive efficiency of the varieties remained essentially the same in both experimental years. Productive efficiency, therefore, appeared to be a more precise and accurate critarion for evaluating the yield potential of wheats. The causes of variation in fertilizer-N utilization and response to N in different experimental years are discussed.
