Effects of Sowing Techniques and Seed Rates on Oilseed Rape Seedling Emergence, Crop Establishment and Grain Yield

Sowing techniques and type of seeding machines play an important role in seed placement and seedling emergence which ultimately affect crop growth and grain yield. The selection of suitable planting methods is dependant upon the time of planting rapeseeds, irrigation methods, amount of previous crop residue in the field and type of planting machines. A field experiment was conducted at Zanjan University research station. The main goals were to determine the effects of different seeding techniques and machines and also different rates of oilseed rape application on seedling emergence, plant establishment and final grain yield. A factorial experimental design in the form of randomized complete block was applied with four replications to measure the effects of the above factors. Two different pneumatic and common mechanical planters were used. Seeds were sown on flat and raised-bed with three levels of 5.5, 7 and 8.5 kg seeds per hectare. Results have shown that the planting machines had significant (P <= 0.05) effect on seedling emergence. Mechanical planter had higher seedling emergence than pneumatic planter. Higher seedling emergence (P <= 0.05) was shown where mechanical planter was used, 8.5 kg/ha seed compared to others. Uniformity on rows and proper seed depth of mechanical planter was significantly greater (P <= 0.01) than pneumatic planter. Flat planting method showed more uniformity on rows (P <= 0.05) than raised-bed methods. The pneumatic planter improved better post-winter plant establishment compared to mechanical planter (P <= 0.05). Finally, grain harvested using pneumatic planter with flat planting method was greater when 8.5 kg/ha seed was applied at sowing in the experiment conditions. However, grain yield was not statistically different.