Preface

The common diseases of crops in China include rice planthopper, powdery mildew, wheat rust, rice sheath blight and rice blast. The common pests include cotton bollworm, cotton aphid, wheat aphid and locust, which have seriously affected the agricultural production in China. In order to reduce the damage of diseases and pests to crops, it is necessary to implement comprehensive control. Integrated control is to use natural control, coordinate the use of all appropriate technologies, control and maintain the pest population below the allowable level of economic damage. Only when the pest density exceeds the limit of allowable level, can we seek the chemical control measures.
          In the application of chemical pesticides to control diseases and insect pests, we should not only consider the selection of effective, safe, economic and convenient varieties, strive to improve the control effect, but also avoid the occurrence of drug pests. We should not only carry out pollution-free production, but also take into account the protection of the soil environment and prevent the destruction of natural resources. At present, there are still many problems in pest control, such as untimely timing, unscientific methods, improper selection of pesticides, inaccurate dosage, untimely medication, incorrect medication methods, and medication at the sight of diseases and insects, which result in labor-consuming, drug-consuming, heavy pollution, rapid increase of pest resistance, and serious harm to crops. In order to publicize and popularize pesticide knowledge and scientific prevention and control of crop diseases and insect pests, promote agricultural science and technology workers and farmers to understand scientific prevention and control technology of crop diseases and insect pests in time, and better serve modern agricultural production, we organized the compilation of the book. The purpose is to give full play to the positive role of pesticides in modern agricultural production, effectively do a good job in the prevention and control of crop diseases and insect pests, and make a modest contribution to the virtuous cycle and sustainable development of agriculture.

前 言

我国农作物常见的病害包括稻飞虱、白粉病、小麦锈病、稻纹枯病、稻瘟病，常见的虫害包括棉铃虫、棉蚜、麦蚜、蝗虫等，它们已经严重影响了我国农业生产。为了减少病虫害对农作物的侵害，就要对其实施综合防治。综合防治就是利用自然控制，协调运用一切适当的技术，把有害生物的种群数量控制和维持在经济受害允许水平以下，只有当有害生物密度超过规定的受害允许水平界限时，才谋求化学药剂的防治措施。
       在应用化学农药防治病虫害时，既要考虑选择有效、安全、经济、方便的品种，力求提高防治效果，也要避免产生药害，进行无公害生产，还要兼顾对土壤环境的保护，防止对自然资源破坏。当前各地在病虫害防治中，还存在着防病治虫时机不及时、方法不科学、药剂选择不当、用药剂量不准、用药不适时、用药方法不正确、见病见虫就用药等许多问题，造成了费工、费药、污染重、有害生物抗药性迅速增强、对作物危害严重的后果。为了宣传普及农药知识和科学防治农作物病虫害，促使农业科技工作者与广大农民朋友及时了解农作物病虫害科学防治技术，更好地为现代农业生产服务，我们组织编写了该书。目的在于发挥好农药在现代农业生产中的积极作用，切实搞好农作物病虫害防治工作，为农业良性循环和可持续发展尽些微薄之力。