بررسي تاثير تقسيط كود نيتروژنه بر عملكرد دانه دو رقم گندم در شرايط خوزستان

Effect of nitrogen spliting on grain yield of two wheat cultivars under Khuzestan conditions

In order to evaluate the split of nitrogen appilcation rate on grain yield and yield components, a field experiment was conducted (in two years from 1995-1997) at Ramin Agricultural Research and Education School. The design of the experiment was a factorial in randomized complete block design with four replications. Experimental factors were two wheat cultivars (Atila and Kauz) and split rate of N application in which was arranged to five levels 141(%50, %50, 0, 0), N2(%25, %50, %25, 0), N3(0, %50, %50, 0), N4(0, %25, %SO, %25) and N5(%25, %25, %25, %25) at four growth stages, (planting time, early stem elongation, and ear emergence and anthesis) respectively. Results indicated that kauz cultivar produced more spikes per m2 (502.42) than Atila caltivar (448.53). However, there was no significant differences within different split rates of N on spike number per m2 which was probably related to rate of tiller production. The obtained results of this experiment showed that cultivar affected spike number per m2, grain number in spike and thousands grain weight in first year of experiment, whereas grain number in spike only was different in second year. There were significant main and interactive effects of cultivar and N spliting on grain yield, biological yield and harvest index. Maximum yield was obtained with N5 treatment (568.4 g/m2) and minimum yield was obtained by N2 treatment (5.42.33g/m2). Considering of 26.7 kg/m2 difference between treatments which would be benefical to farmers. N spliting did not significantly affect yield, but split rate of N application in two growth stages (%50 at planting time and %50 at stem elongation) could be desirable for farmers.