Effects of seed rate and row spacing on yields of wheat and canola

Non-Peer ReviewedThe effects of seeding rate, row spacing and phosphate fertilizer on yields, certain yield components, and quality factors of wheat and canola (rapeseed) w.ere investigated in field plots over a 4-year period. Seed rates were 3, 6, and 9 kg/ha and 45, 90, and 135 kg/ha, respectively, for rapeseed and wheat, both seeded at row spacings of 10, 20, and 30 cm. Phosphate fertilizer was applied at 0 and 25 kg/ha P2O5 placed with the seed. The study was carried out on a Dark Brown Scott loam and a Dark Brown Sutherland clay. Although actual yield and yield differences varied from year to year in response to climatic conditions, highest yields were obtained at the narrowest (10 cm) row spacing, and yields decreased as row spacing increased. Effects of seeding rates on yields varied with years. Under generally favorable moisture conditions, yields of wheat increased with increasing seeding rate. Increased seeding rate reduced yield of rapeseed slightly in one year, but generally had little effect on yields. Plant populations of wheat and rapeseed were higher at narrow row spacing than at wider spacings, and plant populations generally increased with increased seeding rate. The effect of seeding rate and row spacing on protein and P contents in grain of wheat and rapeseed were variable. Phosphate fertilizer placed with the seed of wheat had no significant effect on plant populations, but yields were increased substantially. Fertilizer reduced plant stands of rapeseed, and at the wide row spacings the effect was large enough to prevent a yield increase from the applied phosphate