Investigate effect of nitrogen application on essential oil content and seed yield in different cumin (Cuminum cyminum L.) populations at Qazvin zone

In order to evaluate the beneficial impacts of nitrogen application on cumin species (Cuminum cyminum L.) some yield characters were investigated. The aim of this study were to investigate the interactive effects of different cumin spices and nitrogen application on essential oil content at Qazvin zone (Ishmael Abad station). The experimental design was split plot method based on randomized complete block with four replicates. Certain factors including cumin species (Sabzevar، Bojnourd and Esfarayen localities) and nitrogen application (30، 60، 90 and 120 kg N ha-1) were studied. Our final statistical analysis were indicated that cumin species had significant effect on plant values and highest essential oil yield، essential oil percentage، seed yield، thousand seed weight and harvest index were provided by species of Esfarayen locality and highest biological yield were provided by species of Bojnourd locality. Nitrogen treatment significantly increased plant values and although the highest biological yield، seed yield and thousand seed weight were obtained under 120 kg N ha-1 the highest essential oil yield، essential oil percentage and harvest index were achieved under 90، 60 and 30 kg N ha-1، respectively. The results of this study showed that the selection of species which performed well over a wide range of environment could increase quantity and quality yields of medicinal and aromatic plants and causes optimal usage in agricultural fertilizers.