Grain Yield Response of Three Rapeseed Cultivars to Different Plant Densities

A field experiment was conducted during 2003-4, 2004-5 cropping seasons evalute the effects of plant density on growth and yield of different rapeseed cultivars. The Study was carried out at Ramin Agriculture and Natural Resources University (35 Km from northeast of Ahwaz). The experiment was in the form of split plots' based upon a complete randomized block design of four replications. Main plots consisted of 3 cultivars (Hayola 308, PF7045 and Option501) while subplots of 4 plant densities (50, 70, 90 and 110 plants/m2). Results showed that increase in grain yield (4.20 t/ha) was obtained for Hayola 308 with 110 plants/m2. Option 501 resulted in the least grain yield at 50 plants/m2 (2.55 t/ha). Among yield components, number of pods/m2 and number of kernels per pod were the most affected by plant density and cultivar. The number of pods/m2 increased with increasing plant density, while the number of kernels per pod was decreased. A decreasing trend was observed in 1000-kernel weight up to 90 plants/m2. Considering the advantages of uniform distribution of plants and the adaption of Hayloa to a plant density of 90 plants/m2 it might be appropriate to use this formula for planting rapeseed under conditions similar to the ones in this experiment.