Are herbicides a once in a century method of weed control?

Authors: Davis, Adam; FRISVOLD, GEORGE - University Of Arizona

Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/20/2017
Publication Date: 8/15/2017
Citation: Davis, A.S., Frisvold, G.B. 2017. Are herbicides a once in a century method of weed control? Pest Management Science. 73(11):2209-2220.

Interpretive Summary: Many economic approaches to encouraging pesticide stewardship are built on the assumption that pest susceptibility to pesticides is a publicly-owned, non-renewable resource; in other words, a commons. Our analysis of public data shows that diminishing pest susceptibility to pesticides has not been reflected in U.S. market prices for these products over the past 25 years. Instead, fungicides, insecticides and herbicides have become cheaper over time. Clearly, current incentives for pesticide stewardship are not working, and economic considerations for encouraging stewardship appear to have little influence on the U.S. pesticide market. At the same time, there is an imminent possibility of the evolution of weed genotypes resistant to all relevant herbicides for a given cropping system. A risk of this magnitude requires a different way of thinking about the problem. Rather than using risk models that treat pesticide susceptibility as a finite natural resource, with or without common pool resource aspects, we propose that catastrophic risk models that estimate fat tail risks associated with pesticide loss scenarios should be developed as a means of proactively creating financial and policy instruments to protect producers and consumers alike.

Technical Abstract: Economists have long viewed pesticide resistance as a natural resource problem, in which the stock of pest susceptibility to pesticides is finite, and subject to user costs. Many of the economic approaches to encouraging pesticide stewardship are built on this assumption. Our analysis of public data shows that diminishing pest susceptibility to pesticides has not been reflected in U.S. market prices for these products over the past 25 years. Instead, fungicides, insecticides and herbicides have become cheaper over time. Clearly, current incentives for pesticide stewardship are not working, and economic considerations for encouraging stewardship appear to have little influence on the U.S. pesticide market. At the same time, there is an imminent possibility of the evolution of weed genotypes resistant to all relevant herbicides for a given cropping system. A risk of this magnitude requires a different way of thinking about the problem. Rather than using risk models that treat pesticide susceptibility as a finite natural resource, with or without common pool resource aspects, we propose that catastrophic risk models that estimate fat tail risks associated with pesticide loss scenarios should be developed as a means of proactively creating financial and policy instruments to protect producers and consumers alike.