Response of humic acid and gibberellic acid application on flowering and yield of summer African marigold

Abstract

The objective of the investigation was to evaluate the impact of foliar application of gibberellic acid and humic acid on the growth and flowering parameters of summer African marigold (Tagetes erecta L.) at the Horticulture Section, College of Agriculture, Nagpur, between 2020–21 and 2021–22. The experiment was laid out in Factorial Randomized Block Design (FRBD) with three replications with two factors viz., Factor A consist of four levels of humic acid (i.e., Control, 0.2% humic acid, 0.4% humic acid and 0.6% humic acid) and factor B consist of five levels of gibberellic acid (i.e., 100 ppm, 200 ppm, 300 ppm, 400 ppm and control). Flowering attributes were determined as flower diameter (mm), flower stalk length (cm), single flower weight (g) and number of flowers plant-1. Yield characters i.e., flower yield plant-1, flower yield plot-1 and flower yield t ha-1. The results indicated that gibberellic acid and humic acid produced the best results of all the studied characters. In contrast, the control treatment produced the lowest mean values in African marigold, while humic acid at 0.2% and gibberellic acid at 100 ppm achieved the highest mean values in all flowering and yield attributes.