LAUSR

ABSTRACT Dendrobium is a kind of popular orchid with long display life of flowers. Since it has a long vegetative period to flowering, it is necessary to develop methods to promote flowering. The effects of thidiazuron (TDZ) on flowering and the morphological characteristics of the Dendrobium ‘Sunya Sunshine’ were investigated. One-year-old and uniform height potted plants were used. Plants were spayed and root irrigated with the same amount of TDZ solution in different concentration treatments. The results showed that TDZ promoted the emergence of new shoots, but it did not affect plant morphology, such as the stem height, stem diameter, leaf size. TDZ application of 30 mg·L−1 increased the floral bud formation rate to 87.1%, increased inflorescence number and stalk thickness, but it also decreased the flower number per inflorescence and flower size, and shortened the flowering duration. This study indicated that TDZ could promote flowering, and the optimum concentration of the TDZ solution was 30 mg·L−1.