August 25, 2000
COTTON SITUATION:
The Georgia Weekly Weather and Crops Report for the week ending August 20th listed the crop as 21 percent with open bolls which is similar to the 5-year average of 23 percent open bolls. Crop
conditions vary depending on moisture. Some dryland acreage will be picked in the next week or so.
INSECT SITUATION: Corn earworm and tobacco budworm infestations are spotty and primarily being reported
on late planted cotton. Most of the early May cotton is not attractive to bollworms at this time. Stink bugs remain a primary pest. Detectable populations of silverleaf whitefly can be observed in several
southwest Georgia counties and may pose some problems on late maturing cotton.
SCOUTING FREQUENCY: From early fruiting until open bolls, we recommend that all fields be scouted twice a week. However as cotton
begins to open and has few if any squares in the upper part of the plant, once a week scouting until defoliation should be adequate unless the field continues to show new vegetative growth. Potential insect problems in cotton
with open bolls are aphids, whiteflies, and foliage feeders such as loopers and beet armyworms. Until bolls are mature, sucking pests and foliage feeders will require management. Bolls which are 25 days of age are
relatively safe from attack by bollworms and stink bugs.
Loopers:
Soybean looper is a potential pest during August and September in cotton that is still maturing bolls in the upper part of the plant. To date, no reports of treatable infestations have been received but I have observed low larval populations and numerous moths in Plains this week. Loopers will typically initiate feeding in the lower canopy and work their way up. Some defoliation in the lower canopy may be beneficial as it will allow for better air movement. But excessive defoliation when immature bolls are present will be detrimental. A large percentage of foliage consumed by loopers occurs during the later larval instars (large larvae). Thus, significant damage may occur in a short time period when large larvae are present. Recommended treatments for soybean looper include Tracer and Larvin.
Stink Bugs: Stink bugs remain a potential pest in many fields. Scout and treat on an as-needed basis. In fields where other pests are not present or a concern, the OPs Bidrin or methyl
parathion would be treatments of choice. If silverleaf whiteflies are present in high numbers, consider using the pyrethroid Capture for stink bug control as it will also provide some control of whiteflies.
Spider Mites:
Scott Brown in Colquitt County reports some spider mite damage in some fields. The hot, dry conditions we have experienced are conducive for spider mite infestation.
Silverleaf Whitefly:
Silverleaf whitefly can be observed in several counties in southwest Georgia. Potentially, this pest could cause some problems in the coming weeks, especially on late-planted cotton. Be observant for the buildup of
honeydew on opening bolls. Severe infestations may also cause premature defoliation. This is an unpredictable pest in Georgia in that sustained rainfall will often reduce numbers. Much of the cotton which is
nearing maturity will likely avoid damaging levels of whiteflies.
GEORGIA ASSOCIATION OF PROFESSIONAL CROP CONSULTANTS (GAPAC): The GAPAC has established a web site at
. A membership directory and additional information about the GAPAC can be found in addition to some interesting links related to the cotton industry. This group will also be conducting several harvest aid studies in the upcoming weeks and will be posting those results on the web site.
NO COTTON PEST MANAGEMENT NEWSLETTER NEXT WEEK: The next and final Cotton Pest Newsletter will be sent on September 7, 2000. However, we will continue to update the Cotton Insect Hotline.
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."
Sincerely,
