咖啡锈病流行的空间动态

SPATIAL DYNAMIC OF COFFEE RUST

对病害流行过程格局动态的分析结果表明,咖啡锈病的空间分布格局,不论是水平的还是垂直的方向,都随着病情的加重而由核心分布逐渐向均匀分布转化。严重度小于0.07时,病害中心最为明显;严重度达到0.3以后,病害中心消失。病害在垂直方向由下而上进行扩散。根据这些特征作出如下推论:咖啡锈病主要是以雨水为短距离传播媒介,雨季来临前喷药可获得较好的防治效果。防治咖啡锈病的策略,应该是控制病害中心,防止其扩散和蔓延;这种防治策略的实施,以掌握在严重度为0.07时最为理想。在严重度达0.3以前进行病情调查样株要多些,0.3以后可以适当减少,以节省人力和时间。

Our analysis of spatial pattern of the epidemic of coffee rust (Hemileia vastatrix B & Br.) showed that the distribution pattern of the disease changed not only horizontally but also vertically from aggregative distribution to dispersive one with the progression of the disease. The disease centres were found to be the most evident when the disease severity was less than 0.07 and no such kind of centre was observed when the severity was greater than 0.3. Vertically, the disease spread upwards from the lower parts of the coffee trees. It is considered that the vector of the short-distance spread of the disease was mainly the rain. Therefore, more effective control could be done by spraying the trees with fungicides towards the rainy seasons. The strategy for controlling this disease should be focused on restricting the disease centres so that they could not spread further and the most ideal time for practising this strategy was when the severity was approximately equal to 0.07. The sample size might be somewhat larger whsn the severity was less than 0.3 and might be smaller when it was greater than 0.3 in order to reduce sampling error and at the same time to save time and manpower.