Abstract

Epidendrum is a terrestrial orchid with great potential for commercialization. However, its considerable height makes it difficult for transport and commercialization. Many species have been controled with growth regulators, including orchids and other ornamental plants. The aim of this study was to evaluate the efficiency of two plant growth regulators, paclobutrazol and chlormequat chloride (CCC), on the vegetative growth of potted Epidendrum radicans orchid aiming height control. Paclobutrazol (Cultar) was applied at doses of 0, 5, 10 and 20 mg L^-1, and the CCC (Cycocel) at doses of 0, 2000, 4000 and 6000 mg L^-1. The regulators were applied once or twice a month, via substrate irrigation. Plants were assessed every two months for plant height, number of shoots per pot and number of inflorescences per pot. CCC had no effect on the final height of Epidendrum radicans at the doses applied. Paclobutrazol was effective in controlling plant height at doses of 10 and 20 mg L^-1. None of the products influenced the number of inflorescences produced. Chlormequat chloride at a dose of 6000 mg L^-1 stimulated the production of shoots.

Key words: Paclobutrazol, chlormequat chloride, reduction in height.