Cotton Growers Can Sleep Late for Better Armyworm ControlBy
Its said that timing is everything, and thats
apparently true for cotton growers trying to control beet armyworms.
Tests by an Agricultural
Research Service scientist have shown that applying pesticides
to cotton after sunrise reduces beet armyworm populations by 96
The finding is significant because the beet armyworm costs U.S.
cotton growers tens of millions of dollars in crop losses and
pesticide expenses each year. In 1995, the Lower Rio Grande Valley in
Texas was especially hard hit. The ARS studies were done at the agencys
Research Laboratory, Phoenix, Ariz.
Beet armyworm larvae generally prefer cotton leaves, but as pest
numbers rise, older larvae tend to enter the plants flowers.
Traditional pre-dawn pesticide applications only kill about 12 percent
of the beet armyworms in flowers because the flowers are still closed,
shielding the pests. After sunrise, the flowers open, leaving the
pests vulnerable to chemical control.
To take advantage of the finding, cotton growers will have to do
more than simply spray a few hours later. Growers typically apply
chemicals before sunrise when winds are lighter to reduce pesticide
drift. Also, bees, which are critical for pollination, are still
safely inside their hives at that hour. This means growers must
carefully coordinate after-sunrise pesticide applications with
beekeepers to ensure that hives are temporarily moved to safer
Scientific contact: David H. Akey, ARS
Research Laboratory, Phoenix, Ariz., phone (602) 379-3524, fax
(602) 379-4509, firstname.lastname@example.org.