Determination of the Optimum Time of Harvest in Winter Rape

Field experiment was conducted to determine the optimum harvesting time in winter rape (Brassica napus L.) by investigating the percent oil, 1, 000 seed weight, seed yield, dehiscent pod ratio and oil yield at 46, 50, 54, 58, 62, 66 and 70 days after flowering. Variation of all characters with days after flowering could be explained significantly by second degree polynomial equations. Percent oil and 1, 000 seed weight increased until 62 days after flowering and thereafter these traits decreased, while seed yield increased to 58 days after flowering and thereafter this trait decreased. This controversy was due to the drastic increase in dehiscent pods beyond 58 days after flowering which brought loss in seed yield. These results suggest that optimum harvesting time is 58 days after flowering and it should not be later than 60 days after flowering.