杉木落针病病原菌生物学特性及药剂防治研究

STUDIES ON BIOLOGICAL CHARACTERISTICS OF Lophodermium uncinatum AND CONTROL OF NEEDLECAST OF CHINESE FIR CAUSED BY THIS PATHOGEN

定点观察表明，３月中旬旬平均气温达８．１℃时，杉木落针病病菌（ＬｏｐｈｏｄｅｒｍｉｕｍｕｎｃｉｎａｔｕｍＤａｒｋｅｒ）越冬子囊盘开始释放子囊孢子。４月份旬平均气温为１６．６～２０．１℃，病叶上子囊盘的数量急剧增加。病菌菌丝体在ＰＤＡ、蛋白胨蔗糖和杉木叶煎汁蔗糖培养基上生长良好，生长最适温度２０℃，最适ｐＨ为５．０。药剂防治表明，发病前开始防治时宜选用２５％多菌灵可湿性粉剂，而发病盛期开始防治时宜选用７０％甲基托布津可湿性粉剂喷雾。林间施放多菌灵烟剂和百菌清烟剂的防效分别为６３．８％和５７．３％。

The results of observation (1992～1994) On Chinese fir [Cunninghamia lanceolata (Lamb.) Hook] at oriented spots showed that, overwintered ascocarps begin to disperse ascospores as the temperature of mid of March arrives at 8.1℃, whereas the average temperature of ten-day period of Arpil is in the range from 16.6℃ to 20. 1℃, ascocarps rapidly occur on the infected needles at present. Mycelia of Lophodermium uncinatum Darker isolated from infected needles of Chinese fir grow well on the medium of PDA, peptone sucrose agar or sucrose juice of fresh needles agar. The optimal temperature is 20℃ and the optimal pH is 5.0 for the mycelial growth of L. uncinatum. The experiments of chemical control in the plantations of Chinese fir showed that, spraying 25% carrbendazol WP before the overwintered ascocarps begin dispersing ascospores and spraying 70% thiophanate methyl WP during the climax of ascospore disperation can get satisfactory effect for control of this disease The control effects of discharging carbendazol smoke and chlorothalonil smoke in the plantations of Chinese fir are at 63. 8% and 57.3% respectively.