We have just seen that pesticide use has increased markedly in recent dcades. What has happened to crop losses to pests over this time?
Insects, plant pathogens, and weeds now reduce US crop production by about 37% per year. That is, losses are essentially unchanged since dawn of chemical age !
Given that pesticide use has increased over this time, this means that we are using more and more pesticide just to achieve a fairly constant level of control.
In some cases, losses to pests are actually increasing: For example, in the US, between 1945 and 1989 losses to insects increased 2-fold (doubled: up from 7% loss to the current 13%) in spite of a 10-fold increase in both the amount and the toxicity of the insecticides being used.
Losses to weeds in US agriculture have decreased slightly since 1942 (to 1989); from about 14% loss to about 12%. However, during this time there was about a 100-fold increase in herbicide use.
Over all crops in the US, data published by the Worldwatch Institute indicate that, while pesticide use increased ten-fold between the 1940's and the 1990's, losses to pests also increased from 30% losses up to the current ~ 37% loss rate.
Why on Earth should overall crop losses to pests be roughly stable despite the increases in pesticide inputs?? Click ">>" to read on, or "Navigate " here for reminders on navigations.