The effect of winter planting date on qualitative traits and yield of spring rapeseed (Brassica napus) cultivars in condition of zinc spraying

In order to study the effect of winter planting and zinc spraying on yield and yield components of canola (Brassica napus) cultivars, a factorial split plot experiment was conducted in a randomized complete block design with three replications for two years (2014-2015 and 2015-2016 cropping seasons) at the farm of Seed and Plant Improvement Institute Agricultural Research, Education and Extension Organization , Karaj, Iran.. In this experiment, planting dates ( 24th february, 6th, and 16th March) and Zinc factor in two levels , zinc sulfate spray application and non-application of zinc (spray with pure water) were factorial in main plots and spring cultivars including RGS003, Zafar, Julius, Jerry, Zabol 10, Hyola 4815 in subplots.The results of analysis of data showed that the effect of planting date, zinc spray, cultivar and interaction effect of planting date by cultivar on qualitative traits (grain glycosinolate content and fatty acids percentage) in different planting dates and cultivars had a significant difference at 1% level. According to the results, the highest (66.89%) and lowest (66.02%) oleic acid percentage was obtained in Zafar and zabol10 cultivars, respectively The interaction effect of planting dates by cultivar on the glucosinolate content indicated that the lowest glucosinolate content was obtained in Zafar (8.313 mg/g) and hyola4815 (8.567 mg/g) when they were sown on 16 MarchThe results of this experiment showed that delay in planting, decreased amount of palmitic acid, linoleic acid and oleic acid of seed oil, and increased percentage of linolenic acid, erosic acid and glycoinolate content