Does It Matter Who Scouts?
Lichtenberg, Erik, Berlind, Ayesha Velderman, Journal of Agricultural and Resource Economics
Scouting is the most widely used integrated pest management technique adopted by U.S. growers. This study applies an implicit demand formulation of the Lichtenberg-Zilberman damage abatement model to data from a survey of Maryland field crop growers to examine differences in pesticide demand between growers using scouts trained and supervised by extension and those using chemical dealer employees or scouting themselves. The results give partial support to those skeptical of the quality of scouting by farmers themselves and by consultants working for chemical dealers. Soybean growers using extension-trained scouts had significantly lower pesticide demand than those using chemical dealer employees or scouting themselves. However, no significant differences were found in the pesticide demands for alfalfa, corn, and small grains.
Key words: crop loss, damage abatement, extension, integrated pest management, pesticide demand, pesticides, scouting
Integrated pest management (IPM) is an approach that combines the use of chemical pesticides with nonchemical methods to limit the damage caused by such pests as insects, weeds, diseases, and rodents. Among the nonchemical techniques used in IPM strategies are protection of natural pest enemies, cultivation practices that limit pest overwintering or diffusion, and crop rotation [for a review, see Kogan (1998)]. The most widely used nonchemical method is scouting-i.e., monitoring fields to determine actual pest infestation levels. In scouting-based IPM strategies, chemical pesticides are applied only when the pest infestation level exceeds the economic threshold, usually defined as the level at which the value of crop losses will exceed the costs of pesticide application [see Pedigo, Hutchins, and Higley (1986) for a standard exposition].
Pest management regimes based on scouting and economic thresholds have largely replaced the earlier practices of spraying preventively on a predetermined calendar-based schedule. By the early 1990s, according to the U.S. Department of Agriculture (USDA), scouting was used on 78% of U.S. corn acreage, 77% of U.S. soybean acreage, 80% of U.S. wheat acreage, 86% of U.S. potato acreage, 88% of U.S. cotton acreage, 76% of U.S. fruit and nut acreage, and 71% of U.S. vegetable acreage (USDA/Economic Research Service, 1997; Vandeman et al., 1994).
Despite its apparent widespread adoption, certain aspects of scouting remain somewhat controversial. One bone of contention is the issue of who performs scouting and makes spray recommendations. Scouting is performed by independent crop consultants, by consultants working as employees of farm chemical sales firms, or by farmers themselves. Some believe that only independent crop consultants provide unbiased scouting information [see, for example, Zilberman et al. (1994) for a discussion of this debate]. Those who hold this point of view argue that farmers tend to overestimate pest infestation levels due to lack of training and risk aversion [see Pingali and Carlson ( 1985) for some evidence confirming this hypothesis for apple growers in North Carolina, albeit at a much earlier point in the diffusion of scouting]. They also argue that consultants working for farm chemical dealers overstate infestation levels, use excessively low economic thresholds, or both, in order to increase pesticide sales. Since the majority of scouting is done by farmers and chemical dealer employees, proponents of this perspective posit that scouting may not be a very effective means of reducing chemical pesticide application.
As a counterargument, it has been suggested that consultants working for chemical dealers can be impelled to generate unbiased scouting reports and spray recommendations in order to retain customer loyalty by competition from independent crop consultants, from other dealers, and from farmers with sufficient human capital to scout accurately and apply economic thresholds themselves (Zilberman et al. …