The effect of humic acid and irrigation interval on the growth and yield of corn seed single-cross 704 at Zabol region

In order to investigate the effect of humic acid and irrigation interval on yield and yield components of corn seed of single-cross 704 at the region of Zabol, an experiment as the split-plot has been conducted in a randomized complete block design with 3 replications. Treatments of the experiment included irrigation round as main plot in three levels of 6, 9 and 12 days, and spraying of humic acid as a subplot in four levels of control or every week, every two weeks, every three weeks and every four weeks. The effect of irrigation and spraying of humic acid and their interactions on plant height, number of ear per plant and number of seeds per ear were significant. The highest plant height, number of ear per plant and number of seeds per ear was obtained under 6 days of irrigation round and every two week spraying of humic acid which by 6 days of irrigation round and  every week spraying of humic acid and every three week in same statistical group and did not show any significant difference. On the other hand, the 12 days of irrigation round treatments and every four week spraying of humic acid showed that significantly reduced in the above traits. So that with 12 days of irrigation round and spraying every week and every three weeks of humic acid was placed in the same statistical group. Therefore, the best irrigation round in order to produce corn grain is recommended for 6 days of irrigation round with the use of every two weeks for humic acid spraying for cultivation in the region.