Effects of SADH and MH on Vegetative Growth of Longan (Euphoria longana Lamk.) in Different Orchard Site

Abstract

Effects of concentrations (1, 000, 4, 000, and 7, 000 ppm) and number of spraying (1-3 applications) of N, N-dimethylaminosuccinamic acid (SADH) and malefic hydrazide (MH) at different orchard sites on vegetative growth of longan cv. Chom-Pu trees were studied in the northen part of Thailand. It was found that the diameter of old stem internode, the length of old compound leaf, the diameter of new stem internode, the length of new shoot and the length of new compound leaf were not affected by orchard site, while the leaf flushing, the length of old shoot and the length of old and new leaflet were affected. The diameter of old stem internode and the length of old shoot, old leaflet, new shoot, new compound leaf and new leaflet were not affected by both SADH or MH. In the second orchard site where was in higher level with high aridity, the leaf flushing was delayed by MH, while twice spraying of MH caused the diameter of new stem internode to be smaller than once spraying. Whereas, in the first orchard site where was in moist area, there was interaction between concetration and number of spraying of MH, since the length of old compound leaf was increased by SADH and MH compared with that untreated.