To evaluate the effects of on-farm seed priming treatments and planting date on emergence characteristics, yield, yield components and harvest index of corn, an experiment was conducted in Hamedan, research farm of Bu-Ali Sina University in 2010 as split plot in a randomized complete block design with three replications. Main plots included three planting dates containing early, on-time and late seeding time and subplots were representative of four on-farm seed priming treatments (priming with tap water, urea and zinc solutions and no primed). Results showed that the first planting date using zinc solution increased rate of emergence as well 30%. E mergence percent was increased in the first planting date with using zinc solution by10% and in the second and third planting dates with using urea solution by 13%. However in all planting dates priming with tap water produced maximum grain yield compared to no primed treatment. In this experiment seed priming increased the ear number per square meter and grain rows per ear. Also priming with tap water caused to increase 100 grains weight of corn meanwhile in first planting date priming with tap water and urea solution had more grain number per ear. Priming with zinc in the first planting date increased harvest index. Generally it is concluded that farmers by seed priming especially with tap water and zinc solution could plant corn earlier to increase growth season also if planting is delayed priming with tap water can compensate yield loss.
