湿地松(Pinus elliottii Eugelm),是我县新引进的外来树种。生长快,材质优良,含脂量高,既是良好的速生用材树种,又是含脂量高的采脂树种,经济价值很高。我所一九七三年进行了引种造林,在低丘陵红壤地上,七年生的幼林,平均高624厘米,胸径9.41厘米,长势喜人。但在幼林期间,每年都发生枯梢病(暂名),顶芽枯死,顶端生长受到阻碍,导致侧芽大量发生,变成一株多头,无明显主干,树干矮化,树冠呈球形,严重影响 Pinus elliottii Eugelm is a newly introduced exotic species in our county. Fast growth, good material, high fat content, both good fast growing timber species, but also high lipid content of the resin-landed species, high economic value. In 1973, I started the afforestation program. On the lowland red soil, the seven-year-old young forest grew an average of 624 cm in height with a diameter at the breast of 9.41 cm. However, during the young stands, annual shoot blight (tentative name) occurs, and the top buds die and the top growth is hindered. As a result, a large number of lateral buds occur, becoming a long head with no obvious trunk, dwarf trunk, and a spherical crown, which seriously affects