Effects of planting date and density on the yield of a winter rapeseed cultivar in West Azarbaijan

In order to study the effects of various planting date and plant density on seed yield of the winter oilseed rape cultivar Ceres, an experiment was conducted at Miandoab Agricultural Research Station in the North-West of Iran during the growing season. Treatments including four planting date at intervals of 10 days starting on September 23rd, as main factor, and interrow and intrarow spacings at the levels of 30,45 and 60 cm and 5,10 and15 cm respectively, as subfactors were arranged in a split factorial design in three replications. Analysis of variance showed that the effect of date of planting on seed yield was significant at P = 0.01 level. There were no significant differences between the parameters row spacing and planting date, but the interaction between of planting date and row spacing showed a significant effect. As a result, highest yields were obtained from plots of the first planting date at each of tested interrow spacing levels and from plots of second planting date only at interrow spaces of 45 and 60 cm. The effects of multiple interactions, between 3 factors, were also significant at P = 0.01. It is concluded that the combination of the first planting date and plant spacing at 30cm x 10cm resulted in the highest amounts of seed yield and therefore, can be recommended to be applied under the climatic conditions of West Azarbaijan.