一九七一年是龙泉县连作稻向400公尺以上山区多点试验和大面积扩种的一年。一年来,积累了相当丰富的经验。这里就山区水稻稻瘟病的发生特点和防治原则简要叙述如下。稻瘟病是当前影响连作稻上山的主要病害。但其发病情况随海拔高度而异,一般在海拔400公尺以下发病较轻,在400—600公尺和700公尺的局部地区发病最重,在700公尺以上发病率又趋下降,而且发病时期较迟。在海拔400—600公尺的山区,无论早、晚稻发病都很重,但损失一般早稻轻于晚稻。早稻以分蘖期的叶瘟为主,秧苗期的苗瘟和后期穗颈瘟发生较轻。晚稻无论秧田苗期、本田分蘖期和穗期受害都比较严重,尤其是抽穗以后发病普遍而 1971 is the year of continuous experimentation and large-scale expansion of the continuous cropping paddy in Longquan County to more than 400 meters of mountainous area. Over the past year, has accumulated a wealth of experience. Here on the characteristics of mountain rice blast and prevention principles briefly described below. Rice blast is the main disease affecting the continuous upgrading of rice. However, its incidence varies with altitude. Generally, the incidence is relatively low below 400 meters above sea level, with the highest incidence in some areas of 400-600 meters and 700 meters and the incidence decreasing at more than 700 meters, and Later onset. In the mountains of 400-600 meters above sea level, both early and late rice are very heavy, but the losses are generally lower than that of late rice. Early rice is mainly tillering stage of leaf blast, seedling stage of seedling blast and late panicle blast occurred less. Late rice, regardless of seedling seedling stage, Honda tillering stage and spike injury are more serious, especially after the onset of heading common