STUDY ON THE LEAF SPOT OF ACACIA MEARNSII
Cai Qiujing ( Department of Forestry Science )
Study on the leaf spot of acacia mearnsii was carried out during 1983-1985. All stages of the causual fungus phyllosticta hasijae were found on acacia mearnsii in Changting County, Fujian province. Comidiocarp was 62.3-76.1μ× 41.5-62.2μ in diameter, conidia was 4.3-12.1μ× 1.73-4.32μ in diameter. The optimum range of temperature for the germination of conidia is 20℃-25℃, the germination of conidia requires the high humidity. The disease begins to occur in March and becomes severe in the period of April to October. The occurrence of the disease indicates that it is closely related to rainfall and temperature particularly in April and July. Experiments showed an effective control by applying dilute solution of carb-encloxolx 1000.