论文部分内容阅读
轮作抑制病、虫发生,连作则加重病、虫危害。很早就引起了中外学者和广大农民的注意,积累了很多经验。本文又为此提供了数据。一、连作与病害发生在三个不同年份,从苗期～开花后期的调查中,向日葵连作区的叶部斑病病情指数最高,发病最重。玉米、谷子茬发病较轻。发病茬口顺序为向日葵连作>高粱茬>草木樨茬>大豆茬>玉米茬>谷子茬。营口县所1981年调查,高粱黑穗病的发病率与连作有关。种在玉米茬上的高粱黑穗病只有2.0%。迎茬高粱发病率为12.0%,连作3年为38.0%。
Rotation for the suppression of disease, insects, even as the disease is aggravating, insect damage. Very early attracted the attention of Chinese and foreign scholars and farmers, has accumulated a lot of experience. This article provides data for this purpose. One, continuous cropping and disease occurred in three different years, from the seedling ~ flowering later in the survey, the sunflower continuous crop leaf disease spot disease index highest incidence of the most. Corn, millet stubble incidence less. Crop stubble sequence for continuous sunflower> sorghum stubble> stubble stubble> soybean stubble> corn stubble> stubble. 1981 Yingkou County survey, the incidence of smut sorghum and cropping. Only about 2.0% of sorghum smut is planted on corn stubble. Incidence of sorghum crop incidence of 12.0%, even for three years was 38.0%.