Effect of Humic Acid on Vase Life of Gerbera Flowers After Cutting
Gerbera or Transvaal daisy (Gerbera jamesonii Hook) is one of 10 most important cut flowers in the world. One of the most problems faced the flowers is the short-life after harvest and neck bending. Producers want to increase longevity of these flowers with using chemical solutions. The aim of this experiment was to study the effect of some holding solutions, viz. distilled water (control), humic acid at 25 and 50 ml/l and solution (A) [Silver nitrate (150 mg/l) + Salicylic acid (150 mg/l) + sucrose (2%) + 8-Hydroxyquinoline citrate (8- HQC 200 mg/l)] and different storage periods and their interaction to identify the best treatments to increase flower vase life and other related characters of cut gerbera. The obtained data exhibited that all preservatives solutions caused a marked increment in the studied characters compared to that registered from distilled water (control). In this respect, the individual treatments with either solution (A) or humic acid at 25 and 50 ml/l significantly prolonged vase life, increased the number of open disk florets and water uptake of cut flowers. Moreover, the combined treatments of solution (A) plus humic acid at 25 or 50 ml/l had a superior effect on extending life of flowers, increasing flower diameter (cm) and flowers fresh weight percentage. Control treatment (distilled water) gave the highest percentage of stem curvature after 8 days with recording values higher than 88%, whereas the combination between solution (A) and humic acid either at 25 or 50 ml/l recorded the highest delay for bending neck symptoms. Concerning the effect of storage period, the export conditioning (dry cool storage for 10 days) has shown favourable results on vase life and the other studied characters but 0 days (unstored flowers) surpassed significantly the storage for 10 days. The results of interaction showed that all holding solutions with storage for 0 days (unstored flowers) had the highest effect on reducing the depletion of sugars content, increasing anthocyanin content in flowers and in turn extending vase life. In this respect, the utmost high values of this character was the treatment of holding flowers in solution (A) plus 25 ml/l humic acid x storage at 0 days (unstored flowers). Treatment of the combination of solution (A) plus humic acid at 50 ml/l x storage at 0 days was occupied the second rank in improving studied characters.