EFFECT OF IRRIGATION INTERVALS, PLOWING DEPTH AND PLANTING DATE ON GROWTH AND YIELD OF CORN

Abstract

This study was conducted in the experimental farm (Akad) in Theqar governorate through the season of 2002-2003 to investigate the effect irrigate intervals, depth of plowing and planting date also their interaction on the growth, yield and its component for corn. Split- Split- Plots design was used in this study, main plots include irrigation systems (7 days, 14 days and 21 days) plowing depth as sub-plots include two treatment (0-20) cm and (0-40) cm. concerning sub-sub-plots they include the planting date as follows (3/ July, 18/ July, 2/ Aug). The results of the statistical analysis of the data showed that the plant height, Leave area index, Length of panicls, numbers of grains in panicls, weight of 100 grains and grain yield , had significantly affected by the study factors. Also the results have shown that shortest irrigation interval gave a highest values , and the shortest irrigation interval (7 days) had significantly increased the yield of grain corn which was 8.66 and 10.40 (ton/ha) as compared to irrigation intervals 14 days and 21 days for the growing season of 2002 and 2003 respectively. Also increasing of plowing depth (0-40) cm increased the yield of grain by 15.5% and 12.4 % for the growing season of 2002 and 2003 respectively. There was significant effect for interaction between each two factors. The best combination was obtained from the interaction between 7 days irrigation intervals, planting date (18 July) and plowing depth (0-40) cm.