The Georgia Weekly Weather and Crops Report for the week
ending September 3rd listed the crop as 47 percent with open bolls and 2 percent harvested. Thirty-one percent of the crop is rated good to excellent and 34 percent is rated fair.
INSECT SITUATION: Silverleaf whiteflies continue to be reported in high numbers in some areas, recent rains will hopefully suppress numbers some. A few aphid infestations have been observed. Soybean loopers
have been reported in lush fields.
Silverleaf Whitefly: Silverleaf whitefly (SLWF) can be observed in several counties in southwest Georgia. Damaging populations have been observed in Tift, Colquitt,
Brooks and Grady Counties. The most severe infestations have occurred on late planted (June) cotton. Cotton planted in April and early May appears to have avoided economic injury in most situations and avoiding late
planting should be a management consideration next season. Infestations of SLWF are also higher in hairy leaf compared with smooth leaf cottons. Additional considerations for managing SLWF would be to destroy host crops
and weeds as soon as possible after harvest. SLWF will require management in some areas, and preventive tactics (ie cultural controls) are the first line of defense. Control of SLWF is difficult and expensive with
insecticides due in part to the unpredictable nature of infestations.
Loopers: Soybean looper has been reported in isolated fields. Initial foliage feeding occurs in the lower canopy of the
plant and larvae work their way towards the top. Some feeding low in the canopy is probably beneficial but if immature bolls are present excessive defoliation will reduce yields.
Fall Armyworm: To
date fall armyworm infestations have been light, however small fall armyworms were observed in late planted cotton last week. Be sure to monitor for fall armyworms in later maturing cotton. Most larvae we observed were
etching on the inner surface of bracts and attempting to penetrate the boll once they were a few days of age. Fall armyworm will normally penetrate the lower areas of bolls. If detected early, pyrethroids will offer
good suppression of fall armyworm.
Stink Bugs: Stink bugs remain a potential pest in some fields. Scout and treat on an as-needed basis. Internal boll damage as a monitoring technique has
worked well this year.
Aphids: Aphids have been observed in some fields. Watch for the buildup of honeydew on open bolls.
SEASON WRAP-UP:
This past season has been a difficult challenge from a production standpoint. Widespread problems with insects were avoided for the most part. Early in the year, thrips problems were compounded by dry soil conditions and extremely high numbers of false chinch bugs were observed. False chinch bugs reduced stands in some fields and some acreage was treated for this dry weather pest. Grasshopper numbers were also higher than typically seen early in the year. Plant bug numbers were low in most areas. Aphids built to high numbers in June and early July and caused damage in some fields. We probably treated more acres than normal for aphids. Tobacco budworm and corn earworm numbers were fairly normal. Tobacco budworm, as in years pasts, proved to be difficult to control with pyrethroids in some areas when populations were high. Armyworms remained at low numbers for most of the year. Stink bugs were a primary pest. Threshold populations were first observed in mid-July and continued into September. Silverleaf whitefly was a nagging pest in localized areas.
LAST NEWSLETTER: This will be the last issue of the Cotton Pest Management Newsletter. We would like to thank everyone who contributed information for inclusion into these updates. If you have
suggestions or comments concerning the newsletter please let me know. We hope the newsletter has helped make your season more profitable. Have a safe harvest season.
INSECT UPDATES: Check the
Cotton Insect Hotline (1/800-851-2847) for updates on current insect conditions. The Cotton Pest Management Newsletter is also posted on the Internet at "www.gaipm.org" and then click on "cotton."
CALENDAR: Cotton Production Workshop - December 13-14, 2000 (Savannah, GA)
2001 Cotton Scout Schools - June 2 & 4, 2001 (RDC, Tifton Campus)
Sincerely,
