Evaluation of grain Yield and Nitrogen efficiency indexes in different plant densities and different nitrogen levels in maize (Zea Mays L.) hybrid 704

The object of present study was to evaluate the effect of plant population and nitrogen rate on yield and nitrogen efficiency indexes of maize (Zea mays L, hybrid 704) in Mamasani region, Fars Province at 2008. The experiment was conducted as factorial based on completely randomized block design with three replications, with four plant population (75000, 90000,105000, and 130000 plant ha-1) and three nitrogen rates (200, 300 and 400 kg ha-1). Results indicated that Grain yield was significantly increased from 12910 to 16890 kg ha-1 by increasing plant population from 75000 to 130000 plant ha-1. Nitrogen rates and its interaction with plant population had no significant effect on grain yield. By increasing plant population from 75000 to 130000 plant ha-1 physiological efficiency increased from 31.5 to 45.5, and with increasing nitrogen rate from 200 to 400 kg ha-1 decreased from 43.1 to 32.7. With increasing plant population from 75000 to 130000 plant ha-1 agronomic efficiency increased from 11.3 to 22.5, and with increasing nitrogen rate from 200 to 400 kg ha-1 decreased from 22.1 to 10.8. With increasing plant population from 75000 to 130000 plant ha-1 Apparent Efficiency increased from 25.3 to 48.6, and with increasing nitrogen rate from 200 to 400 kg ha-1 decreased from 50.8 to 32.6. According to the results of the present study, population of 130000 plant ha-1 and 200 kg nitrogen ha-1 is recommended for maximum yield in the region.