EVALUATION ON GROWTH OF SOME Melaleuca leucadendra FAMILIES IN TRAN VAN THOI, CA MAU

Abstract

Melaleuca leucadendra L., an exotic species, is widely planted on acid sulphate soils in the Mekong Delta, particularly in Cà Mau province. However, the productivity of M. leucadendra plantations has decreased due to the use of unselected seed sources, the impacts of climate change, and damage caused by stem borers. In response to the need to improve productivity, wood quality, and pest tolerance for sustainable plantation development, this study was conducted to examine the growth, stem form, and pest resistance of 7 provenances and 80 M. leucadendra families, aiming to select promising candidate families for future breeding. The trial was a randomised complete block design (row-column) with 10 replications, 80 treatments, and was established at the U Minh Forestry Experimental Station in Tran Van Thoi district, Ca Mau province. After 36 months of observation, results showed statistically significant differences among families in survival rate, height, diameter at breast height (DBH), stem volume, and composite stem quality index. In contrast, no significant differences were observed in pest damage severity. Ten promising families (s75, s33, s31, s26, s1, s54, s43, s74, s13, and s29) demonstrated superior performance, with stem volumes ranging from 55.3 to 59.5 m³/ha/year, straight stems, small branches, high quality scores (4.0–4.6), and low levels of pest infestation. The results provide a valuable scientific basis for selecting high-productivity and high-quality M. leucadendra families, contributing to the development of productive and sustainable plantations on acid sulphate soils in Cà Mau province.