出版社：Fundación Científica y Tecnológica de la Asociación Chilena
摘要：Agriculture pests are considered to be generated by man, since they are a consequence of human intervention in the environment. According to the dictionary of the “Real Academia de la Lengua Española” , pest means “something harmful in abundance, that supposes a scourge that afflicts agriculture”. Consequently, a pesticide is “the substance or mixture of substances, capable of preventing, destroying, repelling or mitigating any type of pest, including human or animal disease transmission vectors, undesired species of animals or plants that harm or interfere with the production, processing, storing, transport or marketing of food, agricultural products, woods or animal food; the substances that can be administered to animals for the control of insects, arachnids or other pests in their body. ”
In general it is estimated that losses in crops are caused in about a 14% by insects, an 11% by fungi and in a 10% by weeds. On the other hand, it is known that damage caused by insects is about tenfold the costs of applying pesticides. It is estimated that without application of pesticides, losses can be as high as a 50 % of the crops.
In 1999, EPA published a classification, still current, that separates inert ingredients in four lists; substances producing known toxic effects, potentially toxic, unknown toxicity and those of minimum risk.
Pesticides may be classified according to various criteria, which do not exclude each other, but the most used ones are those based on the name of the pest to which they are intended such as insecticides, herbicides, nematocides, rodenticides etc. and the classification according to chemical group: Organochlorides, Organophosphates(OF), Pyretrines, Organomercurial etc
