Physiological Effects of Different Combinations of Humic and Fulvic Acid on Gerbera

Abstract

Flower quality loss, especially short postharvest life, is a major problem in gerbera production. An experiment was conducted to determine how different combinations of humic substances (HS) affect gerbera. Humic acid (HA) and fulvic acid (FA) applied to nutrient solutions in six combinations including control (nutrient solution only), 80 mg L−1 HA + 20 mg L−1 FA, 60 mg L−1 HA + 40 mg L−1 FA, 40 mg L−1 HA + 60 mg L−1 FA, 100 mg L−1 FA, and 50 mg L−1 FA. The HS application enhanced root architecture, nutrient content, number of harvested flowers, and vase life. Fifty (50) mg L−1 FA extended vase life by 8 days and increased flower number (72.9%). Results suggest that HA and FA (especially 50 mg L−1 FA) can improve quality and quantity of gerbera through improving root architecture, leading to enhanced nutrient uptake and possibly affecting hormone-like activities. It seems that using low concentrations of FA may be part of a solution in improving gerbera flower quality.