Effect of Transplanting Date on Yield and Some Important Traits of Rapeseed Cultivars in Paddy Field of Guilan -Iran

The effect of transplanting date on yield and some important traits of promising rapeseed cultivars was investigated in paddy fields of Rice Research Institute of Iran in Rasht during 2004-2007 cropping seasons for three years. The experiment was conducted in a split plot based on randomized complete block design with three replications. Five transplanting dates of October 23, November 6 and 22 and December 6 and 21 were arranged in main plots and four rapeseed cultivars, Hyola 401, Hyola 308, RGS003 and PF7045/91 were included in main and sub plots, respectively. The results of the combined analysis of variance showed that significant differences exist between the cropping years, transplanting dates and rapeseed cultivars in most traits. Second planting date produced the highest grain, oil and biological yields with averages of 2740, 1208 and 8125 Kg ha-1, respectively. Among the cultivars, Hyola 401 with averages of 2852, 1265 and 8284 Kg ha-1, produced the highest grain, oil and biological yields, respectively. Second planting date produced the highest harvest index with average of 33.95% and fifth planting date produced the lowest harvest index with average of 30.20%. Hyola 308 cultivar with average of 173.8 days for maturity was in the first rank. The highest growth period was observed for first planting date and PF7045/91 cultivar with average of 208 days. Hyola 401 with average of 5.30 cm and Hyola 308 with average of 5.26 cm produced the highest silique length. First planting date produced the highest plant height with average of 135.1 cm and PF7045/91 cultivar produced the highest plant height and height of the lowest silique branch. Based on the results, it seems that the transplanting method for rapeseed cultivars in optimum time (October 23 to November 22) can be an effective method in canola culture in Guilan province, and will produce the highest grain yield and harvest index.