improving irrigation management for hybrid maize seeds in kerman province using a swap model

this research was carried out on corn in the orzuiyeh region of kerman province over two consecutive seasons (2005-6 to 2007-8). the experiment was done as a split plot with a completely randomized block design and four replications. four levels of consumed water (60%, 80%, 100% water requirement, water use based on regional custom) and three varieties (404sc, 700sc, 704sc) were the main factors and the sub-plots, respectively. the measured parameters included irrigation water volume, grain yield, and leaf area index. the results of the swap model indicated that a relatively good correlation existed between observation and calculated data, with irrigation treatment values being close to potential evapotranspiration. there were also significant differences between observation and calculated data for the varieties. these differences were observed in values obtained for grain yield and leaf area index. in conclusion, the corn variety 704sc was more suitable than the other varieties for orzuiyeh region. considering the salinity of the water available for irrigation (ec = 4 ds/m2) in the region, 1100 mm per m2 of water was required to produce the highest relative grain yield. the results also showed a 7% decline in crop production for every increase of 2 ds/m2 in salinity.