The effects of preharvest LED light, melatonin and AVG treatments on the quality of postharvest snapdragon and vase life

Abstract

Snapdragon (Antirrhinum majus) is one of top ten fresh-cut flowers in the United States; however, its short vase life limits its marketability. The purposes of this study were to test the effects of LED light, exogenous melatonin and one ethylene production inhibitor, AVG, on the quality of pre-harvest snapdragon and the prolongation of vase life after post-harvesting. Our results showed that snapdragon treated with 10 h white light followed by 6 h blue light (WB) inhibited stem elongation and lengths of the inflorescences, reduced the number of florets and vase life. On the contrary, snapdragon treated with 10 h white light, 3 h red light, 3 h blue light (WRB) significantly promoted stem elongation, lengths of the inflorescences, and increased the size and number of florets. The lengths of stems and inflorescences increased significantly in all melatonin treatments while quantity and size of florets only increased with 200 µmol·L^-1 melatonin application. Noticeably, vase life was significantly extended with 200 µmol·L^-1 melatonin application and shortened with WB treatment. In contrast to melatonin, all AVG treatments resulted in decreases of the floret size; and changes in stem elongation and inflorescence length were only observed in the treatment with 100 µmol·L^-1AVG. These results showed that pre-harvest treatment with WBR and melatonin can effectively improve the post-harvest quality of snapdragon flowers and 200 µmol·L^-1 of melatonin extended their vase life.