Fulvic acid improves morphophysiological traits and vase life in Alstroemeria ‘Orange Queen’ in soilless conditions

Abstract This study evaluated the potential of fulvic acid as a biostimulant to enhance flowering indices, biochemical traits, and vase life in Alstroemeria ‘Orange Queen’. Conducted under controlled greenhouse conditions, the experiment involved foliar applications of fulvic acid at concentrations of 50, 100, and 200 mg L-¹. The results revealed significant enhancements in key parameters, particularly with the 100 mg L-¹ treatment. This optimal concentration notably increased bud diameter, bud length, and floret fresh and dry weights compared to the control. In addition, fulvic acid application significantly boosted chlorophyll a, chlorophyll b, total chlorophyll, carotenoid, and anthocyanin contents, thereby improving photosynthetic efficiency and flower pigmentation. Enhanced carbohydrate accumulation was evidenced by increased soluble sugar levels in leaves and petals, particularly at 100 mg L-¹. Moreover, fulvic acid significantly extended the vase life of cut flowers, with the 100 mg L-¹ concentration providing the greatest benefit. These findings underscore the effectiveness of fulvic acid as a biostimulant for optimizing both aesthetic and physiological traits in Alstroemeria. By promoting growth, improving pigment composition, and extending flower longevity, fulvic acid emerges as a valuable tool in ornamental horticulture.