Maize hybrids response to nitrogen rates at multiple locations in semiarid environment

Productivity and resource use efficiency are critical issues in sustainable agriculture, especially in high-demand resource crops such as maize. The aim of this research was to compare maize hybrids and nitrogen fertilization rates, evaluating growth, yield and yield components under varying environments. Two year field experiments were carried out at Faisalabad, Sargodha and Sahiwal districts of Punjab, Pakistan. Three maize hybrids were subjected to five nitrogen levels (150, 200, 250, 300 and 350 kg N ha-1). The results indicated a large yearly variability, mainly due to more rainfall during growing season 2005 at all sites. Maize hybrids had significant effect for all the variables under study, except for plant population. Hybrid Bemasal-202 out yielded at all sites by 23 to 35% than hybrid Monsanto-919. Nitrogen rates affected number of grains m-2, 1000-grain weight, grain yield, total dry matter and harvest index with significant differences among nitrogen rates at all sites. The effect of nitrogen availability was amplified at 300 kg N ha-1at all sites. The response of hybrids was different under varying environments. It was concluded that selection of best suited hybrid for each location can increase maize yield at 300 kg N ha-1 in semiarid irrigated conditions.