One advantage

The one important advantage of crop protection chemicals is that we still produce enough food to feed everyone in the world. It must be clearly appreciated that, if we were to stop using all crop protection chemicals tomorrow, hundreds of millions of people would soon die of starvation. It will require at least a decade to produce a significant alleviation in pesticide use, and probably several decades to achieve the maximum replacement of crop protection chemicals with horizontal resistance.

We must recognise also that the efficiency and safety of crop protection chemicals has been improving steadily. Gone are the days when we treated our crops with compounds of lead, mercury, arsenic, and cyanide. After World War II, DDT became available and it had to be applied to crops at a rate of 2kg/ha. Later, the much less hazardous synthetic pyrethroids were developed, and these need be used at only one twentieth of the DDT rate, namely at 0.1kg/ha. A relatively new insecticide, aldicarb, need be applied at a rate of only 0.05kg/ha. In other words, it is forty times more effective than DDT, and it has less hazardous side-effects. Much as we may dislike the use of crop protection chemicals, we must recognise this general trend of improvement, which is likely to continue.

Readers who would like to know more about pesticide use are advised to study The Pesticide Question; Environment, Economics, Ethics, edited by Pimental and Lehman (1993).

The seven principle disadvantages of crop protection chemicals should now be considered, and they can be usefully compared with the use of horizontal resistance.

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