RESPONSE OF CORN YIELD TO WATER DEFICIT AND RICE STRAW MULCH AT SOME GROWTH STAGES

A field experiment was conducted at the Agricultural Experiments and Researches Station, Faculty of Agriculture, Cairo University, Giza, Egypt, during 2008 season.The study aimed to investigate the effect of skipping irrigation water at some corn growth stages with the application of surface cover on grain yield, some yield attributes and water use efficiency.Five irrigation treatments were applied, viz.control treatment (T 1 ), skipping irrigation at, the vegetative stage (T 2 ), grain filling stage (T 3 ), during both vegetative and grain filling stages (T 4 ) and after every irrigation event throughout the crop growth period (T 5 ).Results showed that skipping irrigation was combined with a reduction in yield components and yield.The highest and lowest reductions in the yield were recorded with T 5 and T 2, respectively compared to T 1 .Water deficit during vegetative stage had little effect on yield components and grain yield of corn.Mulched soil increased corn yield and its components compared with un-mulched one.Seasonal water evapotranspiration (ETa) was affected by skipping irrigation.The control (T 1 ), recorded the highest (ETa) value while, (T 5 ) recorded the lowest one.Mulching reduced (ETa) and increased water use efficiency (WUE).The highest (WUE) was achieved with (T 2 ) followed by (T 4 ) and (T 5 ), under un-mulched and mulched soil, compared with (T 1 ).Mulch enhanced the (WUE) as compared to the un-mulched one at all studied growth stages. Key words: corn (maize) yield,