Comparison of organic, nano, and chemical fertilizers on vegetative and reproductive characteristics of Pot marigold (Calendula officinalis L.)

In order to compare the effect of organic, biological, nano and chemical fertilizers on growth characteristics and yield of Marigold, a field experiment was conducted in 2015 in a randomized complete block design with 10 treatments and three replications. Experimental treatments included rotten cow manure, municipal waste compost with and without inoculation of Pseudomonas putida, vermicompost with and without bacterial inoculation, Nanobiomic, ZFM Nano chelate, Bioorganic Nanocomposite, NPK chemical fertilizer (in the ratio of 150: 50 : 50 kg.ha-1 of urea,: triple superphosphate:potassium sulfate, respectively) and control treatment (without fertilizer). The highest leaf area index (3.82) and leaf dry weight (164 g.m2) and total dry weigh (353 g.m2) were observed in vermicompost treatment with P. putida which significantly increased by 53.3%, 86.3% and 57.0% compared to the control, respectively. The highest fresh weight, dry weight and number of flowers were observed at 309 g.m-2, 57 g.m-2 and 284 per m-2 in bioorganic nanocomposite treatment, which increased by 27%, 29% and 59% compared to the control, respectively. Results also indicated that the number of flowers had the highest positive and significant correlation with flower dry weight (r = 0.95**), flower fresh weight (r = 0.93**), leaf area index (r = 0.77**), leaf dry weight (r = 0.75**) and grain yield (r = 0.76**). Finally, the use of cow manure and municipal waste compost fertilizers are more economical than vermicompost and are recommended for Pot marigold.