Effect of sowing date on yield and some physiological index six forage maize cultivars in Rasht region

To investigate the effects of sowing date on yield and some physiological index of six forage maize cultivars in Rasht region, a field study was conducted in 2010. The experimental design was randomized complete blocks with factorial arrangement with three replications. Treatment consisted of four levels of sowing date (22 May, 3, 15 and 25 June), and six maize cultivars (SC 260, DC 370, SC 500, SC 647, SC 700 and SC 704). Results showed that sowing date and cultivar had significant effects on forage yield (dry and fresh) traits. The sowing date 3 June and cultivar SC 700 from a point forage yield (dry 28220.6 kg ha-1 and fresh weight 87017 kg ha-1) were better than other cultivars and sowing dates. The maximum LAI and CGR obtain from sowing date 3 June and cultivar SC 700. Based on the results obtained from this study sowing date 3 June and cultivar SC 700 with more suitable growth indexes is the reasons of increasing in leaf area development, plant photosynthesis activity, dry matter yield and finally more yield, was suggested in Rasht reign conditions.