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Enhance Economic Opportunities for Agricultural Producers
Cotton IPM: Nine Years of Reduced Insecticide Use
Impact Nugget
A comprehensive integrated pest management program implemented in Arizona
cotton for the past nine years has resulted in a combined 58 percent
reduction overall in pesticide sprays for whiteflies, pink bollworm
and Lygus bug, and a corresponding cumulative savings of more than $130
million in reduced pesticide costs; two of the past six years represented
the lowest annual insecticide usage in Arizona cotton in 25 years.
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 in Arizona implemented two new
tools in 1996 and continued their use through 2004: insect growth regulators
(IGRs, effective against whiteflies) and transgenic cotton (containing
Bt effective against pink bollworms). The University of Arizona College
of Agriculture and Life Sciences collaborated with growers, the USDA,
the Arizona Department of Agriculture, the Arizona Cotton Growers' Association,
Cotton Incorporated, industry 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. Both technologies kill their target pests while allowing
natural processes to play a larger role in the control of all other
insects.
Impact
Nearly 100 percent of the cotton acreage in Arizona was sprayed multiple
times for pink bollworm and silverleaf whitefly in 1995; however, from
1999 through 2001 the majority of acres were never sprayed even once
for these two pests. Comparing averages for 1990-1995, a period before
the IPM education and technologies were introduced in cotton production,
with averages for 1996-2004, the following reductions in spray applications
were realized:
For silverleaf whitefly, the average number of chemical sprays dropped
from 3.58 sprays per season in 1990-1995 to 1.15 in 1996-2004, representing
a 68 percent reduction and over $88 million in cumulative control savings,
or about $10 million annually. For pink bollworm, the average number
of sprays per season decreased from 2.72 sprays per season to 0.64 sprays,
a 76 percent reduction, representing $50 million in cumulative savings.
For Lygus bug, sprays have remained static, from 1.57 sprays to 1.49
sprays, a 5 percent increase; however, due to inflation and other increases
in costs of insecticides, there has been a $27 million increase in cumulative
control costs. Yet the total for all three pests, and other minor pests,
reduced from 9.03 sprays to 3.75 sprays, or a 58 percent reduction overall
and a cumulative control savings of $130.4 million over the nine-year
period of 1996-2004. Two of the past six years represented the lowest
annual insecticide usage in Arizona cotton in 25 years. Annual cotton
acreage in Arizona is usually around 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 and created area-wide benefits for all producers.
Furthermore, these plans have been exported for use in California, northern
Mexico, and Australia. Australia experienced similarly dramatic reductions
in broadly-toxic insecticide use one year (2002-2003) after the introduction
of the IGRs and the IPM plan for their use in controlling whiteflies.
Funding
Hatch Act
Smith-Lever 3(b) & (c)
Special Research Grants
Smith-Lever 3(d) (e.g., IPM)
Western Region IPM; Pest Management Alternatives Program
Cotton Incorporated
Arizona Cotton Growers Association
Agrochemical industry
Contact
Peter Ellsworth, IPM specialist
The University of Arizona
Maricopa Agricultural Center
37860 W. Smith-Enke Road
Maricopa, AZ 85239-3010
Tel: (520) 568-2273; FAX: (520) 568-2556
Email: peterell@ag.arizona.edu
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