Sometimes mimicking nature's own way of protecting plants can provide the answer to cost-efficient synthesis of effective crop protection chemicals. The pyrethroids, used as insecticides, are examples of this process. Another is a class of fungicides, the strobilurins, which mimic the natural fungicide strobilurin, a derivative of p-methoxypropenoic acid.
There is a continual search for pesticides with reduced risk. These are used in small amounts, are not susceptible to pests developing resistance, and have low toxicity for non-target organisms (humans, birds, fish and plants). Ideally non-target organisms do not have the same target which is affected by the pesticide or do not share the target's vulnerability that is exploited by the pesticide.
There are many hundreds of pesticides in use and being developed. This unit describes some specific examples currently being used from each of the three groups -herbicides, insecticides and fungicides.