Influence of Organic and Chemical Fertilizers, Common and Nano Iron, Zinc and Manganese on Yield and Yield Components of Fennel (Foeniculum vulgare L.)

The effect of organic and chemical fertilizers, application as well as nano and common micronutrient on yield, yield components and essential oil of fennel were investigated by experiment as factorial based on randomized complete block design with three replications at the Faculty of Agriculture, University of Maragheh in 2017. The first factor was application of organic and chemical fertilizers including control (without fertilizer), vermicompost, urban waste compost and chemical fertilizer, and the second factor was foliar application of Fe, Zn and Mn (control, common and nano forms). Results showed that the highest number of umbels per plant was obtained by using chemical fertilizer, the highest number of grains per umbelet and grain yield were obtained by chemical fertilizers and urban waste compost application, and the highest biological yield was obtained with all three types of fertilizers application. Regarding the application of micronutrients results indicated that, the highest number of grains per umbelet, 1000-grain weight and grain yield were obtained by foliar application of common micronutrients and the highest biological yield was obtained by application of both types of common and nano micronutrients. The analysis of variance results showed that the interaction of organic and chemical and micronutrients was significant on the number of umbelet per umbel, essential oil percentage and essential oil yield. So that the highest number of umbelet per umbel (12.9) was observed in chemical fertilizer + nano micronutrients application by 39.6% increase compared to control (no application of any fertilizer) and the highest percentage of essential oil (2.78%) and essential oil yield (4.53 g.m-2) were obtained in chemical fertilizer + common micronutrients by 54.5% and 98.7%, respectively. In general, the results of this study showed that the application of organic fertilizers of urban waste compost and vermicompost to replace the chemical fertilizer, as well as foliar application of common or nano-micronutrients for improving the yield components and qualitative and quantitative yield of fennel are effective.