To study the effect of humic acid on yield and yield components of marigold, a complete randomized experiment with 5 levels of humic acid treatment (0, 500, 1000, 2000, 4000 mgl-1) with 3 replications and 15 experimental plots was carried out. Analysis of variance showed that the effect of humic acid treatments on all measured traits was significantly at the 1% probability level. Mean comparisons revealed that treatment with 2000 mgl-1 humic acid, had the most flower number per plant, fresh weight and branches & nodes number.
