Effects of Sowing Date and Plant Density on Qualitative and Quantitative Forage Yield of Sweet Corn KSC403 in Spring Sowing

In order to study the effects of sowing date and plant density on quantity and quality of yield of sweet corn KSC403, an experiment was conducted in Gorgan Reaserch Station for three years (2001-03). Four swoing dates (9th April, 29th April, 19th May and 8th June), and four plant densities (45000, 55000, 65000 and 75000 plants per hectare) were evaluated in form of factorial experiment (4 4) within randomized complete block design. The results showed that quality and quantity of forage (stem, leaf, cob ear, spout ear) were affected by sowing date and plant density. Maximum dry forage yield, crude protein and crude fiber, 7724, 694 and 2139 kgha-1 respectively, were obtained in the second planting date. Dry forage yield, crude protein and crude fiber were also influencd by plant densities and maximum dry forage yield, crude protein and crude fiber, 7330, 644.4 and 2048 kgha-1 respectively, were obtained in 75000 plant ha-1 density. With increasing plant density, forage yield increased and maximum forage yield was obtained in 75000 plants per hectare density. As ear length decreases by increase in plant density, 55000-65000 plants per hectare is the best density for sweet corn to obtain the highest forage yield and ear quality in Golestan province.