Evaluation of organic and biofertilizer inputs application on yield, yield components and essential oil content of marigold (Calendula officinalis L.)

The experiment was conducted as factorial based on randomized complete blocks design with three replications. The first factor was including as application of 0, 10and 20 tons cattle manure per hectare and the second factor application of humic acid, nitroxin, humic acid +nitroxin and control. The highest plant height, lateral stems number and biological yield were obtained by applying 20 and 10 tons cattle manure per hectare and the highest flowers number, leaf chlorophyll index, dry yield of flowers, number of grains per capitol, and 1000-kernal weight by applying 20 tons cattle manure per hectare. Plant height, number of flowers per plant, number of grains per capitol and biological yield were reached to maximum value by applying of humic acid +nitroxin. The lateral stems number and 1000-kernal weight with the combined application of humic acid +nitroxin or separate application of nitroxin showed the highest increase compared to the control. Application of catlle manure 20 tons per hectare increased the biological yield by 18.9%, and 10 and 20tons per hectare increased the essential oil by 24.8% and essential oil yield by 43.3%, compared to the control. The highest dry yield of flowers, essential oil content and essential oil yield were significantly obtained in humic acid +nitroxin treatment compared to the control. The highest grain yield was obtained in two treatments of nitroxin and nitroxin +humic acid application without significant differences with each other at the level of application of 20 tons cattle manure per hectare.