Effects of Flowering Stage at Harvest, Storage Method, and Application of Gibberellin and Benzyladenine on Flower Opening and Tepal Senescence of Dutch Iris ‘Blue Magic’ Cut Flower

Abstract

Dutch iris ‘Blue Magic’ cut flower rapidly loses iris ornamental value in a vase. In this experiment, we distinguished between two factors: incomplete flowering and tepal senescence, and further investigated the effects of the flower bud development level at harvest, storage method, and pretreatment with gibberellin (GA₃) and benzyladenine (BA) as a stem dip. Incomplete tepal development in a vase occurred regardless of the flower bud development level at harvest. As the 10°C dry storage period exceeded 2 days, the tepal development was suppressed and the vase life was shortened. As with dry storage, the longer the storage period, the shorter the ornamental period even in wet storage. Application of a 100-ppm concentration of GA₃ as a stem dip to the cut flower which had been stored under dry conditions for 1 day, promoted tepal development. However, when the same GA₃ treatment was applied to flowers which had been stored under dry conditions for 3 days, its flowering was not promoted. The application of BA or mixture of BA and GA₃ inhibited senescence and shrinking of the tepal, leading to a prolonged flower vase life.