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Competitive Agricultural Systems in a Global Economy
Cotton IPM: Reducing Insecticide Use
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 2001: insect growth regulators
(IGRs, effective against whiteflies) and transgenic cotton (containing
Bt effective against pink bollworms). Annual cotton acreage in Arizona
is usually over 250,000 acres. 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.
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 1996-2001, 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 1.16 in 1996-2001, representing
a 68 percent reduction and over $62.4 million in cumulative control
savings. For pink bollworm, the average number of sprays per season
decreased from 2.72 sprays per season to .72 sprays, a 73 percent reduction,
representing $34.2 million in cumulative savings. For Lygus bug, sprays
actually increased very slightly, from 1.57 sprays to 1.59 sprays, a
2 percent increase, representing a $24.6 million increase in cumulative
control costs. However, the total for all three pests, and other minor
pests, reduced from 9.03 sprays to 3.92 sprays, or a 57.9
percent reduction
overall and a cumulative control savings of 87.6 dollars over
the six-year
period of 1996-2001. 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
Hatch Act
Smith-Lever 3(b) & (c)
Special Research Grants
Smith-Lever 3(d) (e.g., EFNEP, CYFAR)
Other CSREES (Western Region IPM; National Pesticide Impact Assessment
Program, Western Region)
Commodity (Cotton Incorporated)
State (Arizona Cotton Growers Association)
Other (Industry: Agrichemical)
Contact
Peter Ellsworth, IPM specialist
Maricopa Agricultural Center
37860 W. Smith-Enke Road
Maricopa, AZ 85239-3010
Telephone: (520) 568-2273
FAX: (520) 568-2556
peterell@ag.arizona.edu
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