By
Bonnie Coblentz MISSISSIPPI
STATE -- The topic of many causal conversations this winter
is no light matter to farmers who must make decisions for
the upcoming year based in part on the weather. January
has not brought the freezing temperatures it usually does,
and warmer weather means more crop pests can survive until
spring. But a lack of cold weather did not stop the rain,
which has brought area flooding to some portions of the
state. Dr.
Charles Wax, professor of geosciences at Mississippi State
University, said east central Mississippi averages 50 freeze
days a year. As of the first week of February, the area had
just 15. "Through
December, MSU had only nine freezes, while we typically
average 13," Wax said. "We had just five freezes in January,
instead of the average 16 for the month." To
farmers, this means more trouble with bugs. Dr. Blake
Layton, extension entomologist at MSU, said temperatures to
date have been kind to boll weevils, cotton's No. 1
pest. "Boll
weevils are susceptible to winter kill, but it takes a
temperature of 10 degrees or lower at the site where the
boll weevil is in diapause (hibernation)," Layton said.
"Some boll weevils will die at higher temperatures, but to
really have a significant impact on boll weevil populations,
you have to get to that lower temperature." A good
winter kill of boll weevils is more important in 1998 than
it has been in previous years, Layton said. About 340,000
acres of Mississippi cotton in the hills went into the boll
weevil eradication program last fall. This greatly reducing
the numbers going into diapause, but a heavy winter kill
would have been a tremendous aid to the eradication
effort. "The
Delta's 600,000 acres are not yet being eradicated, and a
very heavy population of boll weevils went into
overwintering there," Layton said. "Growers need to be
concerned about these overwintered weevils this
spring." While
temperatures have not killed bugs, rain has helped. Area
flooding from the heavy winter rains has likely killed many
boll weevils unhurt by the mild temperatures. Boll
weevils are not the only pest affected by winter weather.
Stink bugs, traditionally a pest of vegetables, corn and
especially soybeans, also are susceptible to winter
kill. "A mild
winter opens the gate for higher stink bug populations,"
Layton said. Tobacco
budworms and bollworms are rarely affected by Mississippi's
temperatures. The mercury usually does not drop low enough
to hurt them as they overwinter as pupae an inch or deeper
in the ground. Flooding, however, can affect the number that
survive. "The
overwintering pupae just can't survive well in soils that
experience prolonged flooding," Layton said. "In mid-winter,
some can survive temporary flooding, but those that are
beginning to break diapause in the spring are more likely to
be affected." River
flooding has not yet been a problem in the state, but
Wayland Hill, a civil engineering technician at the Army
Corps of Engineers in Vicksburg, said strong El Nino years
are wet years for the state. "Generally,
El Nino means a cooler-than-normal winter, not from cold
temperatures but from cloudiness," Hill said. "It also means
a lot of rain here and upriver in the Mississippi and Ohio
river basins, which are big contributors to the Mississippi
River." The
Mississippi River was high in January, peaking in Vicksburg
at 37.4 feet on Jan. 23 and 46.1 feet in Natchez on Jan. 23
and 24. Flood stage at Vicksburg is 43 feet and 48 feet at
Natchez. Some farmland and a few houses were flooded, but
river water has not been a serious problem yet this
year. Hill
said the Mississippi River is falling quickly now, but in
1983, the last strong El Nino year, the river had a high
January, dropped to normal levels in February, then shot
back up in March and April. Released:
Feb. 9, 1998
Mississippi
Agricultural News:
Weather Has Not
Helped Farmers
Contact: Dr. Blake Layton, (601) 325-2085
Visit: DAFVM
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Last Modified: Friday, 17-Aug-07 14:27:50
URL: http://msucares.com/news/print/agnews/an98/980209bl.htm
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