Effects of vernalization and plant regulators on growth and flowering of Gladiolus grandiflorus

Abstract

Gladiolus corms were held at 22°C or vernalized at 4° or 8°C for two weeks and then soaked for 24 hours in 1,000 ppm gibberellic acid (GA) or 1,000 ppm indolylacetic acid (IAA) before being planted in the field. There were no differences in the period of time for shoot emergence among the treatments. Treatment of gladiolus corms with 4°C for two weeks increased plant height in relation to storage at 22°C (control). Gladiolus corms soaked for 24 hours in 1,000 ppm GA reduced the number of leaves of the plants, and corms vernalization at 4°C for two weeks increased the number of leaves. Corms vernalization at 4° or 8°C for two weeks improved plant quality. There were no differences in the dates of anthesis among the treatments. Flower quality was improved by corm vernalization at 4° or 8°C for two weeks.