Competitive Agricultural Systems in a Global Economy
Reducing Insecticide Use in Arizona

Issue

Insecticide applications in cotton typically account for about half of all insecticide use in the United States. New materials on the market are now enabling cotton growers to reduce their spray applications while maintaining competitive yields. These technologies also help growers implement more ecologically-based IPM programs and become less dependent on broadly toxic insecticides.

What has been done?

An integrated pest management program implemented two new tools in 1997 and continued their use in 1998: insect growth regulators (IGRs, effective against whiteflies) and transgenic cotton. The University of Arizona College of Agriculture collaborated with growers, the USDA, the Arizona Department of Agriculture, the Arizona Cotton Growers' Association, Cotton Incorporated, and others. Both of these tools are highly effective against pests, but safe to humans and the environment. Based on insect hormones, growth regulators disrupt the growth and development of insects. Transgenic cotton is genetically engineered to carry its own biological insecticide, targeting lepidopterous pests, within the plant tissues.

Impact

As a result of this program, during 1999 the average foliar insecticide use in Arizona cotton was the lowest in 20 years, according to state records first kept in 1979. Overall, 1999 had the lowest number of foliar sprays against all insect/arthropod pests in cotton during the 90s, and the lowest costs per acre during the same period. In 1990, growers applied about 11 sprays during the season at an average cost of $113.76. By 1999 this number had dropped to 1.74 (between one and two sprays) at an average cost of $34.50.

For silverleaf whitefly (SWF) in particular, the number of sprays dropped from 1.80 per season in 1992 to 0.40 for the season in 1999. Lint quality went from "very sticky" in 1992 to "very clean" in 1999. In 1992 SWF sprays cost an all time high of $91.80 per acre, and amounted to nearly 75% of the total foliar insect control budget. By 1999 growers spent an average of $10.83 per acre on SWF, which was only about 30% of the total foliar insect control budget. This was the lowest amount of money per acre spent to control SWF since its introduction to the state in the early 1990s.

This success was mainly due to the efforts of the Arizona IPM program and the availability of IGRs and transgenic cotton in reducing the number of insects that appeared. Weather patterns and other factors may also have influenced the appearance of fewer numbers of insects in 1999. Annual cotton acreage in Arizona is usually over 250,000 acres.

Along with resistance management, these IPM efforts reduced insecticide use, conserved biological control agents, and enhanced sustainability and profitability. The availability of these selected technologies, which are harmless to predaceous insects, has provided growers the opportunity to employ IPM practices that enhance the population levels of beneficial insects in the field.

Funding

Contact

This report is one of 29 impact statements submitted by the University of Arizona College of Agriculture to the USDA's 1999 CSREES Science and Education Impacts database in Washington, D.C. An impact statement is a brief summary, in lay terms, of the economic, environmental and/or social impact of a land-grant program. It states accomplishments and their payoff to society.
Located at http://ag.arizona.edu/impacts/2000/insecticide.html
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