施用Chlormequat Chloride、Uniconazole及Paclobutrazol矮化劑以控制盆栽迷你型馬拉巴栗之生長

Abstract

Braided miniature Pachira macrocarpa Walp. is a new product which has a great export potential. Due to its rapid-growth nature of the plant, a method to control the plant size is essential for commercial 244-production. In this study, effects of growth retardants on plant height and shape control in this crop were investigated. Three types of mini Pachira macrocarpa plant namely: single cane, green braided, and braided and pruned by heading back, were treated, either by soil drenching or spraying, with chlormequat chloride (CCC; 1000, 2000, or 4000 mg‧L^(-1)), uniconazole (UCZ; 15, 20, or 25 mg‧L^(-1)), or paclobutrazol (PBZ; 100, 200, or 300 mg‧L(-1))solutions. The results showed that drenching or spraying with either UCZ or PBZ retarded the plant height effectively, but CCC did not. When the concentration of a growth retardant was fixed, regular drenching and spraying consumed different volumes of the liquid per plant or pot, and therefore generated different efficacies in retarding plant growth. The effect of spraying could be substantially improved by increasing the application volume. Application of growth retardants did not affect the occurrence of braid loss. Leaf curling, a side effect of growth retardants, could be lowered by using lower concentrations of the chemicals. Over-sized braided Pachira macrocarpa could be pruned by heading back and then applied with UCZ at 15 mg‧L(-1) or PBZ at 100 mg‧L(-1) in order to reshape the plants for suitable height, compact canopy, and having acceptable quality for export.