Study of the Potential of Sequential Planting of Supersweet and Sweet Corn Hybrids in Greenhouse Conditions of Jiroft Region in Iran

Sweet corn has a short life cycle and its sequentinol planting is possible and can be grown in rotation with cucumber in greenhouses of Jiroft in Iran as a profitable crop. A split-plot arrangement in randomized complete block design with three replications was carried out in two growing seasons of 2008-09 and 2009-10 in the greenhouses of Agricultural Research Station of Jiroft to determine the most appropriate sowing date and cultivar of sweet corn. Sowing date at three levels 1st, 11th and 21st August were assigned in main plots and five hybrids: Chase, Temptation, Basin, Challenger and Obsession were randomized in sub-plots. The sowing and harvest were conducted three times per year. First under open air inside the greenhouse and the others inside the roofed greenhouse. In the second sequential planting which was under plastic roof of the greenhouse, the main plots were planting date (14th October, 31st October and 12th November) and the sub-plots were the same hybrids. In the third sequential planting the main plots were planting date (14th January, 30th January and 21st February) and the sub-plots were the same sweet corn hybrids. In the third sequential planting, young sweet corn plants spent part of their growing periods under open air by removing the plastics. Results showed that the highest fresh ear yield (24.06 t ha-1) was obtained from the planting date of 21st August. In the second suquential planting the highest and lowest ear yields were obtained from planting dates of 14th October and 12th November (24.79 and 17.69 t ha-1, respectively). Also, the highest ear yield was produced by cultivar Challenger (22.13 t ha-1). In the third sequential planting, the highest ear yield was obtained from planting dates of 14th January
(18.5 t ha-1) and the highest yield for hybrids from Obsession (18.11 t ha-1). In conlusion, 21st August and all hybrids for the first planting, 14th October and Basin (with 21.39 t ha-1 forage yield) and Obsession (with 22.74 t ha-1 forage yield which is important in winter) for the second sequential planting and 14th and 30th January and Obsession and Temptation hybrids for third sequential planting are recommended.