Phytochemical Study and Improving the Essential Oil Yield of Cuminum cyminum L. by Spraying the Metabolic Activator of Pluramin and the Growth Regulator of Bioxa under Rainfed Condition

Cumin (Cumin cyminum L.) the only cumin crop in Iran, which is rich in secondary metabolites has great economic value and is. In order to evaluate the effect of foliar application of growth stimulant of pluramin and bioxa on this plant, a field study was conducted as a factorial experiment in a randomized complete block design with four replications in the research farm of Shahid Madani University of Azerbaijan in 2017- 2018. Experimental factors included foliar application of pluramin at the concentrations of 0, 2.5 and 5 g.l-1 and bioxa at the levels of 0, 5 and 10 ml.l-1. The essential oil was extracted using hydro-distillation method in Clevenger apparatus and analyzed by GC/MS. The effect of foliar application of pluramin on 1000-seed weight, number of seeds per umbel and essential oil yield and the effect of foliar application of bioxa on plant height, number of seeds per umbel and content and yield of essential oil were significant. The interaction of experimental factors on the number of seeds per umbel, content and yield of essential oil was significant. Comparison of means showed that the highest content and yield of essential oil with a significant difference belonged to the foliar application of 10 ml.l-1 bioxa; after that, spraying 2.5 g.l-1 of pluramin produced the highest content of essential oil. The major compounds identified in all treatments included 3-carn-10-al, para-cement, p-comic aldehyde, gamma-terpinene, beta-pinene and 2-carn-10-al. The highest essential oil yield was obtained from foliar application of 10 ml.l-1 bioxa, which was significantly different from the other levels of foliar application. That is, simultaneous foliar application increased this compound. The highest amount of para-cymene, gamma-terpinene and beta-pinene was obtained by spraying 10 ml.l-1 bioxa and the lowest amount of these compounds were obtained by spraying 5 g.l-1 pluramin and 5 ml.l-1 bioxa. Overall, the results showed that foliar application of growth stimulants of pluramin and bioxa can improve the yield and composition of cumin essential oil under the rainfed conditions.