Change in plant densities combined with zinc application affects rapeseed seed oil and fatty acid composition

Abstract

In order to investigate the effect of zinc application on qualitative characteristics of rapeseed cultivars in different plant densities, a factorial split-plot experiment was carried out based on randomized complete block design with three replications for two cropping years (2014–2016) in Karaj, Iran. In this experiment, plant density at three levels (40, 60, and 80 plants m−2), zinc application at two levels (0 and 0.3% at pod formation stage) as factorial in main plots and six rapeseed cultivars, including GKH3705, GKH2624, GKH0224, GK-Gabriella, Neptune, and Elvis were assigned to sub-plots. The interaction effect of plant density × Zn × cultivar on oil yield, oleic acid, linolenic acid, linoleic acid, palmitic acid, erucic acid, and glucosinolate content of seeds and interaction effect of plant density × cultivar on oil percentage was significant at 1% level. According to the results, all the tested cultivars showed a positive response to zinc application on different plant densities, especially the density of 40 plants m−2. GK-Gabriella cultivar at density of 40 plants m−2 and under zinc application had the highest oil yield and the highest content of oleic, linoleic, and palmitic fatty acids. Moreover, having low and standard erucic acid and glucosinolate, this cultivar is recommended for canola production.