اثرات تنش خشكي و سايكوسل بر عملكرد ارقام ذرت در كشت دوم

Effects of drought stress and cycocel application on yield of maize varieties in second crop

In order to study the effects of drought stress and cycocel application on the some vegetative traits and grain yield of maize varieties as second crop, an experiment was conducted at agricultural research station of Jihad-Keshavarzi in Khoy region of Iran during 2005 growing season. Experimental design was a split-split plot based on randomized complete block design (RCBD) with four replications. The factors consisted of irrigation as the main factor in three levels (irrigation after 70+5, 100+5, and 130+5 mm evaporation from class A pan), 260 and 301 com varieties as subfactor and cycocel in two levels of 1.5kg/ha effector material and without application as sub-subfactor. Results showed that drought stress caused reduced culm diameter, ear lengh and diameter, hundred grain weight, and biological and grain yield. Variety 301 had more ear diameter than variety 260, significantly. This can be attributed to the longer growth duration of the variety 301. Application of cycocel increased stem diameter, length and diameter of the ear, hundred grain weight, biological yield, grain yield and the harvest index. Generally, It was concluded that the irrigation after 70 mm evaporation and the application of cycocel can play major role in increasing of maize grain yield.