US IPM target fails to reduce pesticide use

Chemical pesticides can have adverse effects on human health and the environment, and their long-term effectiveness will be increasingly limited as pests continue to develop resistance to them, according to a new study from the US General Accounting Office (GAO).

It is becoming increasingly clear that sustainable and effective agricultural pest management will require continued development of and increased use of alternative pest management strategies such as integrated pest management (IPM). 
In 1993 the US Department of Agriculture (USDA) established a goal of implementing IPM on 75% of US crop acreage by 2000. Based on a sample of growers, USDA estimates that some level of IPM had been implemented on about 70% of the nation’s crop acreage as of the end of the year 2000. 
    The GAO says that the implementation rate is not a good indicator of progress toward an originally intended purpose of IPM – reducing pesticide use. In estimating the IPM implementation rate, USDA counts a wide variety of farming practices without distinguishing between those practices that tend to reduce pesticide use and those that may not. In fact GAO analysis shows that the subset of IPM practices that tend to reduce reliance on pesticides, often referred to as biologically-based IPM practices, has been far more sparsely implemented than the overall IPM rates indicate. 
    USDA’s strategic plan stated that the department’s policy was to support implementation of biologically-based IPM practices. In 1998, USDA reported to the US Congress that some crops were managed under rudimentary IPM methods, and that the IPM initiative would be geared toward helping growers move toward more biologically-based practices. In addition, the US Environmental Protection Agency representatives told the GAO that they had tried to encourage the adoption of biologically based pest management practices. In spite of these policy statements, USDA’s IPM definition does not emphasise biological pest management practices, and as a result implementation of biological IPM has been low. For example, while USDA estimated that IPM had been implemented on 76% of corn (maize) acreage in 2000, the implementation rates of biologically-based IPM practices on corn cropland ranged from less than 1% for disrupting pest mating to about 18% for use of biological pesticides.

Increasing applications
US research has demonstrated that some IPM practices can reduce pesticide use as well as pest management costs, while still maintaining crop yield quality and quantity. However, while IPM has yielded significant benefits in certain crops and locations, IPM does not yet appear to have quantifiably reduced nationwide pesticide use. In fact, total use of agricultural pesticides, measured by weight of active ingredient, has actually increased since the beginning of USDA’s IPM initiative. Pesticide use has increased from 900 million pounds (408 million kg) in 1992 to about 940 million pounds (446 million kg) in 2000, even given a decrease in agricultural land. 

Risky pesticides widely used
The use of the riskiest pesticides has however declined over the same period. Risky pesticides, including organophosphates and carbamates, and probable or possible carcinogens, have decreased from 455 million pounds to about 390 million pounds. But this means the use of the riskiest pesticides still accounts for over 40% of pesticides used in US agriculture.

Recommendations
The GAO has put the following recommendations to the USDA:

• Establish effective department-wide leadership, coordination, and management for nationally funded IPM efforts;
• Clearly articulate and prioritise the results the USDA wants to achieve from its IPM efforts and resources on those results, and set measurable goals for achieving those results;
• Develop a method for measuring the progress of nationally funded IPM activities toward the stated goals of the IPM initiative.

Agricultural Pesticides, Management improvements needed to further promote integrated pest management, GAO-01-815, Washington, US, www.gao.gov

[This article first appeared in Pesticides News No. 54, December 2001, page 19]