Effect of planting date and plant density on morphological traits, LAI and forage corn (Sc. 370) yield in second cultivation

ABSTRACT: In order to study the effect of sowing date and plant density on morphological traits, LAI and forage corn yield, a split-plot experiment was carried out in the research field of Islamic Azad University, Gonabad Branch, Gonabad, Iran in 2007 based on a randomized complete block design with three replications. The sowing dates of the main plot at three levels were July 4, July 21 and August 6. The sub-plot was of plant density at four levels 50, 80, 110 and 140 thousand plants/ha. The results showed that delay in sowing from July 4 to August 6 decreased significantly the plant height, stem diameter, leaf area index, total fresh and dry yield by 15.7, 20.9, 42.1, 24.7 and 25.9%, respectively. With increasing plant density from 50000 to 140000 plants/ha, stem diameter decreased by 21.6%, but plant height increased 15.1%. Moreover leaf area index and total dry yield, increased 3.39 and 1.84 times, respectively. According to the results, the treatment of sowing date of July 4 with density of 140000 plants/ha recommended for the cultivation of forage corn in Gonabad, Iran as second cultivation