2012年4月5日星期四

Modern Pesticides and their Advantages


Modern pesticides have a number of advantages over many of the older options. Many pesticides commonly used in the past were found to be harmful to human health; they also contributed to environmental destruction by killing large numbers of helpful animals. Many of the older pesticides, such as DDT, were eventually banned in developed countries due to their link to cancer, birth defects, and declines in animal species. Modern pesticides have the significant advantage of having been developed with an eye towards possible effects of their use. Though they are still dangerous in large doses, modern pesticides have to be approved for use in the United States by the FDA, and by other regulatory agencies elsewhere in the world.
Another advantage of modern pesticides, and perhaps the most significant, is their increased effectiveness. Old pesticides naturally lose effectiveness as insects and other harmful pests gain resistance. Because insects typically have such a short time between generations, they evolve resistance to pesticides quite rapidly. Because of this resistance, farmers using older formulations must apply much more pesticide to their fields than farmers using modern pesticides. In fact, the most effective anti-mosquito insecticide, DDT, has now lost nearly all of its effectiveness in the locations where it was most frequently used. In addition to the cost of using excessive pesticide, farmers must consider the danger to themselves, their families, and their employees. Spraying large amounts of pesticides inevitably raises exposure to the chemicals, as up to 98% of applied pesticides are carried away from their intended targets.
Modern pesticides are designed to be effective while posing the least possible threat to humans and wildlife. One advantage of modern pesticides is that they are designed to degrade quickly in the soil, meaning that pesticides cannot leach into soil and groundwater, where they may be absorbed into crops. Quickly-degrading pesticides are also less likely to spread beyond their intended area of use.
New pesticides can be developed with the benefit of a greater understanding of pests" biology, enabling targeted formulations which spare benign or helpful organisms. One example of this specific formulation is illustrated in the case of potato cyst nematodes, who emerge to feed on potatoes after the plant releases a specific chemical. If this chemical is applied to the field early on in the crops" development, the nematodes emerge early and starve to death.
Modern pesticides have a number of advantages over older pesticides. They are much more effective, which means that less chemicals have to be applied. Applying less pesticide saves money, so that using modern pesticides can be cheaper than using old ones. In addition, when farmers use less pesticide they reduce environmental harm caused by pesticides. They also reduce the total content of the chemicals in their crops, which makes the produce safer for human consumption. New formulations enable targeted applications specific to individual pests. This allows farmers to get rid of one pest without killing all the other organisms in their fields, who may have a beneficial effect.

Yangzhou pioneer chemical CO.,LTD 

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