Managing Bollgard Cotton
Guide A-221
Shane T. Ball, Extension Agronomy SpecialistKatie Elson, Extension Scout/Technician
College of Agriculture and Home Economics, NMSU
This publication is scheduled to be updated and reissued 6/03.Bollgard (BG) cotton varieties can be planted later than non-BG cotton because BG cotton can effectively control cotton bollworms and pink bollworms. However, under heavy bollworm pressure, BG cottons may require supplemental control such as insecticide applications to avoid economic losses.
General
Two to 4 plants per row foot is the optimum planting rate for BG cotton varieties. The optimum nitrogen fertilization rate should be between 45 and 50 pounds of nitrogen per acre per bale of the expected yield. Avoid applying too much nitrogen because it promotes vegetative growth and delays fruiting. Over-irrigation (especially in mid- to late-season) also promotes excessive vegetative growth.
Crop Monitoring
Producers growing BG cottons should use cotton crop monitoring techniques to determine their crops' vegetative growth and fruit retention.* A timely application of Pix should be considered when crop monitoring indicates a potential problem developing.
Early-Season Insects
Early-season insect control is the same for BG as for non-BG cottons. Management strategies include seed treatments and at-planting insecticide treatments (when needed), which avoid disrupting beneficial insects.
Mid- to Late-Season Insects
Non-BG cotton and BG cotton require similar management decisions regarding insecticide applications for boll weevils, aphids, and white flies. Thresholds for treatments for these insects are the same as for non-BG cottons. For more information, contact NMSU's Extension entomologist at (505) 646-5280.
In addition, under heavy bollworm pressure (especially during peak bloom) producers may need to apply supplemental insecticide treatments. We strongly suggest that selective insecticides be used to minimize the disruption of beneficial insects.
Crop Termination
Early cut-out and early crop termination are recommended for all cottons grown in New Mexico. Also, immediate destruction of the post-harvest stalk by discing and shredding is very important for controlling late-season insect infestations and reducing over-wintering populations of boll weevils and pink bollworms.
* To obtain NMSU publications on cotton crop monitoring or other topics, contact the Department of Agricultural Communications, Bulletin Office, P.O. Box 30003, MSC 3AI, New Mexico State University, Las Cruces, NM 88003, or phone (505) 646-2701. To download publications form the World Wide Web, point your browser to http://www.cahe.nmsu.edu/resources/jfagproducers.html
New Mexico State University is an equal opportunity/affirmative action employer and educator. NMSU and the U.S. Department of Agriculture cooperating.
Printed June 1998Electronic Distribution June 1998