生物防治的主力——微生物农药-福建农林大学.PPT

Unit 3: Pesticides in agriculture and the environment Learning objectives Define the following terms: NOEL ADI Differentiate among the terms: acute急性的, sub-acute and chronic慢性的 testing for toxicity. Compare the relative acute toxicities of chemicals using LD50 values. What is the goal of agriculture? 农药的历史 the advent of pests is coincident with the advent of agriculture and that makes pests a human invention before 2,500 bc Sumerians闪族人 were using sulfur compounds to control insects and mites By 2,500 bc the Chinese figured out plant phenology生物气候学 and adjusted crop planting times to avoid pest outbreaks By 1,200 bc China was using plant-derived insecticides and had already developed seed treatment practices .They also used chalk石灰 and wood ash for control of stored product pests, and mercury and arsenic compounds for body 虱子 The earliest record for using natural enemies was in China about 300 BC- they used predatory ants to help control caterpillars毛虫 and beetles in citrus plantings they understood the concept of food webs and natural population regulation early 1700’s the rediscovery and introduction into Europe of various botanical insecticides like pyrethrum 除虫菊, and tobacco leaf infusion SO The first step in any pest management program is to accurately identify the pest The big change During 1750-1880 farming in Europe became more of a commercial enterprise than subsistence生计 Insecticide era In the late 1930’s the Swiss and Germans were making significant advances in synthetic chemistry Specifically they were working with petroleum distillates and developing the science of organic chemistry The insecticide era The insecticide era began in 1939 with DDT and continued until 1962 DDT The insecticidal properties were discovered by a Swiss, Paul Müller, working for Geigy Corp. DDT is in the class of compounds called chlorinated 氯代烃类hydrocarbons DDT During WWII western allies同盟国 use DDT for mosquito, flea跳蚤 and lice control Müller received the N