Determination of Sowing Dens and Plant Densities of Castor Bean Crop in Umia Region

In order to evaluate the effects of different sowing dates and plant densities on yield and yield components of castor bean crop, an experiment using a factorial based on randomized complete blocks with three replication was conducted at the research farm of west Azarbaijan Agricultural Research Center during 2007- 08. The first factor included three sowing dates in spring and the second factor included three planting density. Analysis of variance indicated that the effects of different sowing dates and plant densities on diffrent characteristics of castor bean crop were significant. Interaction sowing dates and plant densities was significant on biological yield. Results indicated that the highest grain and oil yield were producedof the last sowing date (5 June) and plant density 25000 plant per hectar. According to these results, last sowing date (5 June) and plant density 25000 plant per hectar are recommended.