Investigation the effect of different levels of nitrogen and nitroxin fertilizer on yield, growth and physiological indices of maize hybrids (Zea mays L.)

In order to investigate the yield, yield components, growth and physiological indices of maize hybrids in response to Nitroxin bio fertilizer application containing inoculant Azotobacter choorcoccum and Azospirillum brasilenese bacteria, in addition to the amounts of nitrogen fertilizer, this experiment was performed as split plots based on randomized complete blocks design with four replications. Main plots consisted of combining four levels of fertilizers treatment (100 percentage chemical fertilizer, 75 percentage chemical fertilizer 100 percentage bio fertilizer, 50 percentage chemical fertilizer 100 percentage bio fertilizer and 25 percentage chemical fertilizer 100 percentage bio fertilizer) and sub plots included maize hybrids (Single Cross 704 hybrid, Mobin hybrid and Karoun hybrid). Results showed that maximum biological yield, grain yield, one thousand grain weight and ear length were belonged to combined use of 50 percent nitrogen fertilizer plus 100 percent Nitroxin bio fertilizer in Karoun hybrid. Single Cross 704 hybrid in the amounts of 100 percent chemical fertilizer application, had the highest number of grain per ear, number of grain per row, inoculation percentage and lowest length of ear without grain and percentage of ear without grain. The maximum length of ear without grain and percentage of ear without grain was obtained from treatment 75 percent nitrogen chemical fertilizer application plus to 100 percent bio fertilizer and Mobin hybrid. The investigation of results showed no significant difference among fertilizer treatments, as well as hybrids in terms of chlorophyll index. However, Karun hybrid had a higher chlorophyll index than two other hybrids.