Optimizing water and nitrogen requirement in maize (Zea mays L.) under semi arid conditions of Pakistan

Water and nitrogen are the most important factors,play their role in better growth and yield of maize. to find out effective use of resources a field experiment was conducted to study the effect of irrigation regimes and nitrogen rates on growth and yield of maize hybrid at agronomic research area,university of agriculture,faisalabad,during 2009. the experiment was laid out in randomized complete block design with split plot arrangement having three replications. three irrigation regime i.e.,i1 (eight irrigation),i2 (six irrigation,two missed at vegetative stage) and i3 (seven one missed at grain filling stage) were kept in main plots and four rates of nitrogen; n1 (150 kg ha-1),n2 (200 kg ha-1),n3 (250 kg ha-1) and n4 (300 kg ha-1) were randomized in sub plots. results showed that maximum leaf area index (4.92),number of grains per cob (490),grain yield (8.49 t ha-1) and harvest index (47.73%) were achieved in n3 treatment with i1 irrigation regime while the highest biological yield (17.97 t ha-1) was recorded in n4 treatment with the i1 irrigation regimes. the minimum1000-grains weight (314 g),biological yield (12.48 t ha-1) and grain yield (4.67 t ha-1) were recorded in the combination of i2 and n1 treatments. water stress at six and twelve leaves stage simultaneously decreased grain yield 30% while water stress at grain filling stage decreased 20% yield.