Eeffect of nitrogen application rate in the field on germination indices of three winter canola (Brassica napus L.) cultivars in standard germination test

In order to evaluate the effect of different rates of nitrogen fertilizer on viability and germination indices of three winter canola (Brassica napus L) cultivars, an experiment was conducted based on randomized complete block design with factorial arrangement of treatment in four replications. The treatments included four levels of nitrogen (N) 0(control), 70, 140 and 210 kg ha-1 and three canola cultivars Okapi, Orient and Modena. Results of standard germination test indicated that there was a significant difference between cultivars in terms of germination percentage, seedling dry weight and seedling weight vigor index. The effect of nitrogen was significant on all traits expect seedling weight vigor index. Furthermore, there was a significant interaction between cultivar and nitrogen on germination percentage, seedling length, meangermination time and seedling length vigor index. Additionally it was observed that germination percentage decreased by applying nitrogen in all three cultivars, and the highest germination percentage (98%) was achieved from Okapi cultivar without using nitrogen (control). The highest seedling length vigor index was obtained from Okapi cultivar by applying 210 kg ha-1 nitrogen. Additionally Modena cultivar seeds, produced by using 140 kg ha-1 nitrogen, germinated faster than the other seeds.