The Effect of Different Irrigation Water Levels on Grain Yield, Yield Components and Some Quality Parameters of Silage Maize (Zea mays indentata Sturt.) in Marmara Region of Turkey

This research was conducted in Bursa, Marmara region, Turkey, in order to determine grain yield and some morphological traits which affect the silage maize response to different irrigation water amounts. The grains' percentage of crude oil and of crude protein were determined. Field experiments were planned following randomized complete block design with three replications and included six irrigation treatments. Irrigation treatments were created as water levels of pan evaporation (E-pan) applied via drip irrigation [1.25 x E-pan (I-125), 1.00 x E-pan (I-100), 0.75 x E-pan (175), 0.50 x E-pan (I50), 0.25 x Er,, (125) and 0 x E-pan (I-0)]. The highest value of grain yield was found to be 18,268 kg ha(-1) in the I-125 treatment, which represents excessive water. A quadratic relationship between grain yield and irrigation water applied was obtained. Deficit irrigation decreased grain yield and yield components except the percentage of crude oil and crude protein of grain, but improved the efficient use of irrigation water. Relationships between the grain yield and each yield component were positively significant. The highest correlation coefficient in the research gave the relationship between grain yield and plant height (r=0.957-). The results revealed that 1.25 x E-pan and 1.00 x E-pan treatments are preferable for higher yield. The results of this study also suggest that if water is limited, the application of 0.75 x E-pan can be recommended as optimal treatment, because the best compromise among yield, yield components, quality and irrigation water use efficiency for maize was achieved with this application.