Pest and Disease Problems of Native Tree Seedlings in Northern Thailand: some examples

ABSTRACT: FORRU is identifying framework tree species for the restoration of Northern Thailand’s upper watershed forests. Since 1994, research at FORRU has focused on collecting seeds of native species, and testing germination and seedlings growth rates under nursery conditions. However, the current emphasis is on improving necessary technologies and increasing production of high-quality seedlings for planting. Large productivity stepped-downs occur at the germination and potting stages, but losses to pests and diseases are also significant. The incidence of phytophagous insect outbreaks has increased with the age of the nursery, and certain seedling species are affected by recurring problems with disease. Little information is currently available on the scale of these problems, or the types of disease that are present. This survey has highlighted areas for concern, with a view to developing elementary and cost-effective management strategies. Some such strategies are suggested. With further monitoring of the prevalent pests and diseases, together with a more detailed assessment of the recommended treatments, it will be possible to make well-informed decisions about seedling productivity targets and the overall suitability of certainty species the forest restoration.