Cotton News Letter Vol. 18, No. 7,  July 5, 2000

Cotton Situation:  I know I'm beginning to sound like a broken record complaining about the drought, but we are still needing rain in the worst way.  Many areas of South Carolina haven't received a decent rain this year.  The June 25 issue of the “South Carolina Crop and Weather Report” stated that 46% of the cotton was in poor to fair condition, 45% was good and 9% was considered in excellent condition.  Blooms should be found in about 50% of cotton fields this week. Insect Situation:  There's really not much to talk about at this time in regards to cotton insect pests.  Bollworm and budworm moth numbers are low, there are few eggs being reported and most of the worms have cycled out or were done in by beneficials.  Tarnished plant bug numbers are still low.  We are beginning to see a few aphids in most fields. Pyrethroid Resistance Management:  The following guidelines were developed to aid farmers in the management of pyrethroid resistance.  Bt cotton should be the foundation for a management plan.  Where control problems have been observed in the field during the previous season, and/or pyrethroids have been ineffective in the current season, it will become necessary to utilize non pyrethroid insecticides for control of economic infestations.  Other classes of insecticides will reduce selection pressures for pyrethroid resistance due to their different modes of action. In severe problem areas (see definitions below) 1.  Plant Bt cotton varieties and for supplemental bollworm control in July use two applications of:     a. Tracer @ 2.2 oz./acre, or     b. Larvin @ 1.5 pts./acre, or     c. Steward* For a third application a pyrethroid could be used for bollworm and/or stink bugs. 2.  In conventional cotton varieties use Tracer, Larvin or Steward as above and avoid using pyrethroids.  Methyl parathion or Bidrin may be used for stink bug control. Areas with moderate to localized problems 1.  Plant Bt cotton and for supplemental bollworm control in July use one or two applications of:     a. Tracer @ 2.2 oz./acre, or     b. Larvin @ 1.5 pts./acre, or     c. Steward*  If another application is needed for bollworm or stink bug control, a pyrethroid could be used. 2.  In conventional varieties use Tracer, Larvin or Steward as above.  Where there have been no control problems observed in previous years, pyrethroids may be used beginning after the first week in July, but limit the number of applications to 2-3.  If treatments are needed either early in the season or after the July generation, utilize Tracer, Larvin or Steward. No problems yet (no field failures) Utilize good IPM practices and treat promptly when scouts report problems.  Practice good pyrethroid stewardship as outlined above.  If control problems occur when all proper application techniques have been utilized, report the incident to your County Agent.  *We have applied to EPA for a Section 18 for the control of beet armyworms and pyrethroid resistant bollworms in 2000. The following categories should be utilized to determine the type of resistance management program that will best fit a particular situation: 1.  Severe problem areas -- Farms or areas where pyrethroids have been ineffective in controlling bollworms in several fields.  After two or three applications there are unacceptable numbers of large worms still damaging plants. 2.  Moderate to localized problem areas -- Farms or areas where there may just be a field or two where there are unacceptable numbers of large worms following two or three pyrethroid applications. 3.  No problem yet -- Farms or areas where there are no apparent problems controlling bollworms.  Cotton Insect Hotline: The Cotton Insect Hotline is sponsored by the S C Cotton Board.  The toll free number is 1-877-629-1474 (notice also that this number is shown in the header at the top of the front page of this newsletter).   A recorded message is updated on each Tuesday and Friday to provide timely information about insects and cotton production.  By the way, I want to sincerely thank the cotton growers of South Carolina for their recent approval of the referendum that will continue to fund cotton research.  Mitchell Roof  Extension Entomologist

This information is supplied with the understanding that no discrimination is intended and no endorsement by the Clemson University Cooperative Extension Service is implied. Brand names of pesticides are given as a convenience and are neither an endorsement nor guarantee of the product nor a suggestion that similar products are not effective. Use pesticides only according to the directions on the label. Follow all directions, precautions and restrictions that are listed. The Clemson University Cooperative Extension Service offers its programs to people of all ages, regardless of race, color, sex, religion, national origin, disability, political beliefs, sexual orientation, marital or family status and is an equal opportunity employer.  Clemson University Cooperating with U. S. Department of Agriculture and South Carolina Counties.  Issued in Furtherance of Cooperative Extension Work in Agriculture and Home Economics, Acts of May 8 and June 30, 1914.  Public Service Activities