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Cotton Growers Watch For Rain And Insects
MISSISSIPPI STATE -- Thrips are the only ones having a field day in Mississippi's cotton as the mild winter and dry, windy conditions have growers scouring their crops and the skies for relief.
Blake Layton, cotton entomologist with Mississippi State University's Extension Service, said thrips are more abundant than normal, but in numbers similar to last year.
"As alternate host plants for thrips dry up and winds kick up, more thrips are moving into cotton," Layton said. "Generally, cotton becomes safe from thrips once it reaches the third or fourth leaf stage, but if it remains dry and plants begin to stress more, thrips will remain a threat for longer than normal."
Layton said farmers who did not use soil-applied systemics may have to treat every untreated cotton field for thrips. Where systemic insecticides are used, it is not uncommon to see large numbers of adult thrips because they need time to feed on the treated plants before control occurs. High numbers of immature thrips are evidence that systemic insecticides are not providing adequate control.
The mild winter is likely the cause of higher-than-normal sightings of unusual pests like cutworms, sugarcane beetles and false chinch bugs. When the crop is no longer vulnerable to thrips, other pests will become an issue. Tarnish plant bugs and boll weevils may begin impacting the crop when it reaches pin-head square stage.
Boll weevil eradication efforts have been underway in Mississippi hill cotton since the fall of 1997. The South Delta program started the following year, and last fall the final portion of the Delta began eradication efforts.
"Early trap counts are showing more boll weevils than we would like to see at this stage of eradication. A number of fields, especially in the hill section near the Delta, will need pin-head square applications," Layton said. "There are no automatic treatments in the program this year. Sprays will be administered when at least two weevils are trapped per 40 acres of cotton."
Growers need to make sure all cotton fields have traps. Since traps are spaced further apart this year, Layton said it is even more important that any traps knocked down by equipment be restored promptly.