Effect of planting date on some morphological and phenological traits of corn (Zea mays L.)

In order to investigate the effect of planting date on some morphological and phenological traits of six medium maturity promising corn hybrids in the north of Khuzestan, an experiment was conducted as a split plot based on a randomized complete block design with four replications at Safi-Abad Agricultural and Natural Resources Research Center of Khuzestan in 2008. Main plots included six planting dates (June 30th, July 7th, 14th, 21st and 28th and August 4th) and sub plots consisted of six hybrids of corn and the hybrid SC704 was considered as a control. Results showed that both vegetative growth period, growing degree-day (GDD) and total growth were influenced by planting date and variety. The highest GDD was obtained at first planting date. Among different planting dates, maximum plant height was obtained on August 4 with 203 cm. Among different hybrids, maximum plant height related to SC 704 with 190 cm. Both ear length and first ear height had an increasing trend toward the late planting dates. By considering the corn-wheat rotation and harvesting problems of corn cultivation in summer Khuzestan province, planting date of July 28 is suggested for warm climates like Khouzestan.