Evaluation of Spring Sweet Corn (Zea mays var saccharata) Production in Different Planting Date under Plastic Cover in Gachsaran Province

In order to evaluate the performance of spring sweet corn (Zea mays var saccharata) at different planting dates under plastic cover, a split plot experiment based on RCBD with three replications was conducted in Gachsaran, in southwest of Iran, during 2009-2010 growing season. Four sweet corn hybrids (Merit, Challenger, Chase and Basin) were used as main factor and five sowing date (15th and 25th Jan, 4th, 14th and 24th Feb) as sub factor. The results showed that hybrid effect was significant on the days to tassel and ear emergence, days to harvest, ear harvest index, ear length, number of row per each ear, wet biological yield and 1000 grains weight, at 1%, and ear wet yield and grain yield harvest index at 5% probability levels. Also the effect of sowing date was significant on the days to tassel and ear emergence, days to harvest, ear wet yield, ear harvest index, ear diameter, ear length, biological yield, and 1000 grains weight at the 1% probability level. 'Basin' and 'Chase' hybrids were determined to have highest and lowest ear wet yield (17.09 and 15.13 t.ha-1) respectively. The highest and the lowest wet ear yield (16.81 and 15.06 t.ha-1) belonged to 15th Jan. and 24th Feb. respectively. 'Basin' hybrid and 'Challenger' with 8.39 and 7.59 t.ha-1 grain yield were found to be highest and lowest yields. The highest and the lowest grain yield (8.41 t.ha-1 7.45 t.ha-1) were recorded for 15th Jan. and 24th Feb. respectively.' Merit' and 'Chase' hybrids were determined to have longest and shortest days to ear harvest (94.3 and 86.2 days). Longest and shortest days to ear harvest (101.5 and 82 days) were recorded in 4th Jan. and 24th Feb. Sowing date and hybrids interaction effects showed that the longest and shortest days to ear harvest (104.7 and 78.3 days) were calculated in 4th Jan. of Merit and in 24th Feb. for Chase. Based on these results, it can be concluded that 'Basin' hybrid Feb. 24 is the most suitable cultivar to be produced in Gachsaran.