The effects of drought Stress and different sowing date on some quantitative and qualitative characteristics of three corn hybrids (Zea mays L.) in the region of north of Khuzestan

This experiment was done on the basis of split-split-plot design in completely randomized block design with three replicates in north of Khuzestan in 2015. Irrigation treatments (irrigation after 70, 90 and 120 mm evaporation) as main-plot, planting date (1 and 20 July and 9 august) as sub-plot and hybrids (704, Karoon 701, and AS71) as sub-sub-plot were carried out. Results showed that the effect of planting date and hybrid on grain yield, 1000-kernel weight, number of kernel rows and number of kernels per row was significant, also the effect of planting date×hybrid on leaf area, the effect of irrigation×hybrid on stomatal conductance and the effect of planting date, hybrid and planting date×hybrid on plant height was significant.
Results showed that the highest number of kernels per row was observed in the third planting date and 704 and Karoon 701 hybrid, the highest number of kernel rows was observed in the third planting date and 704 hybrid, the highest amount of 1000-kernel weight was observed in the third planting date and Karoon 701 hybrid. The highest amount of grain yield was observed in the third planting date. The hybrid of Karoon 701 had the highest leaf area in third planting date. AS71 hybrid had the highest amount of leaf area in first irrigation period. AS71 in first irrigation period and 704 and Karoon 701 hybrid in third irrigation period had the highest stomatal conductance. Also AS71 had the highest plant height in third planting date.