Bollworm larvae commonly penetrate bloom tags after hatching to enter the top of small bolls. After cotton emerges, consistent scouting can best identify which pests are threatening the crop.
Integrated pest management (IPM) is a comprehensive approach to insect, weed and disease management to protect against yield loss and deterioration of cotton fiber quality. IPM provides many benefits for farmers, society and the environment. IPM practices offer farmers flexibility, good use of resources, opportunities to increase yields and profits, new technology and reduced potential for pest resistance.
IPM for insects includes planting cotton with traits that confer resistance to insects, nematodes and other pests; using seed treatments; scouting and identifying insect pests; making timely insecticide applications when needed; and using cultural practices to diminish the threat from insects.
Consider insect resistance or tolerance when selecting varieties. For example, early-maturing varieties are less exposed to late-season infestations of pests such as tobacco budworms, bollworms, armyworms and loopers. Additionally, some cotton varieties provide tolerance to diseases and nematodes, which are pests that can delay maturity and increase susceptibility to insects.
Dual-gene, Bt-transgenic cotton varieties provide better suppression of bollworms and other caterpillar, or lepidopteran, pests than the single-gene Bollgard varieties did. New three-gene Bt technologies are now entering the market that will provide even better performance against worm pests. Additionally, the three-gene Bt technologies will help prevent the development of resistance in worm populations.
Use the correct insecticide seed treatment and rate to effectively and economically control early-season insects in cotton production. Seed treatments protect cotton seed and young cotton plants from insects, nematodes, disease and other threats to plant health and yield. Additionally, in-furrow, at-plant insecticides can provide added protection against early-season insect pests.
After cotton emerges, consistent scouting, which includes sampling and insect identification, is the best way to know what pests are in the field and whether or not they will threaten yields and profits. Problem infestation areas may be related to soil conditions. If only one side of a field shows insect problems, it may be related to an invasion from a field border. Keep in mind that in cotton fields, problem areas with sharply defined edges could be a sign of insect damage, or they may be the result of nematode or herbicide injury.
When scouting fields, start at a different point each week. Pick a random pattern in advance and walk without consciously choosing good or bad areas. Sample after regular intervals – every 20 steps or so. Walk to within 30 feet of each field edge, as many problems start from the sides of the field.
Take samples of insects and scan the entire field for possible insect damage while walking from one site to the next. Observe the plants around the sample site while looking for patterns or variations. If insects and damage are not easily identified, consult county Extension personnel or a pest identification guide.
Thresholds and best scouting methods vary by insect pest, cotton variety, timing of planting and geographic location. Thresholds for pest populations that require insecticide applications also vary, and the determination should be based on timely regional information from sources such as a university Extension service.
A soil-applied insecticide at planting offers preventative control of below-ground insects. Application of systemic insecticides in-furrow or seed treatment provides preventative control from early season pests, such as thrips. Timely, judicious use of foliar insecticides is also an important component of IPM in cotton when insect counts indicate that pest populations have exceeded economic thresholds. Insecticide applications can knock down pests such as plant bugs, stink bugs and bollworms and can also help reduce larvae hatching and egg-laying on leaves by adult insect populations, which can harm current and future crops. Consideration should be given in the selection of products to be applied to minimize effects on non-target arthropods which serve as biological control agents. In some situations, insecticide treatment is a risk-management decision. Threshold numbers are typically best determined by professional cotton consultants and Extension agents.
Cultural practices can affect insect pest populations. For example, try to plant cotton away from corn to reduce exposure to insects such as plant bugs, which can migrate into cotton. Spraying the edge of a cotton field adjacent to a soybean field is one tactic for controlling migrating insects. Crop residue management also helps reduce overwintering insect populations.
Crop rotation also helps fend off insect populations. Soil sampling every few years to test for nematodes is another helpful practice. Be aware of populations of natural predators and parasites. Treatment thresholds can sometimes be increased with high predator populations.
Controlling weeds early helps overall plant heath and seedling vigor. Good weed control throughout the growing season will help protect against cotton insects such as aphids, thrips, plant bugs, cotton fleahoppers and beet armyworms. Timely herbicide applications reduce insect breeding areas in host weeds such as silver leaf nightshade, pigweeds, waterhemp and marestail.
Reduced-till production systems can intensify insect problems in many cases. Aphids and other cotton insects may build up in areas where previous crop residue has been left on the soil surface at planting. A burndown herbicide applied three to four weeks prior to planting can reduce infestation risks. When soil is disturbed during land preparation, scout for white grubs, cutworms and any other insects that may be exposed.
Bayer Solutions to Help Control Insect Pests in Cotton
The best approach to managing insect pests in cotton is preventative control. Bayer offers season-long insect control options from Bt trait cotton varieties, to seed treatments, and to foliar insecticide products.*
Planting a dual Bt trait variety – such as TwinLink®, which is available in most new Stoneville® and FiberMax® varieties – protects against worm pests such as budworm, bollworm and armyworm. Additionally, specific varieties feature genetic tolerance to root knot nematodes. Growers can control a wide range of insect-host weed pests, including Palmer amaranth, marestail, morningglory, Russian thistle and grasses, by planting FiberMax or Stoneville cotton varieties with the GlyTol®, LibertyLink® traits followed by Liberty® herbicide.
A good seed treatment is an excellent way to control insects and protect cotton above and below the ground. The Bayer portfolio of seed treatment products offers the best seed-applied solutions available on the market today, from seedling disease protection to protection against early-season insects and nematodes.
For areas with a history of early-season insect infestations, growers can use Aeris® insecticide/nematicide seed treatment, available on commercially treated Stoneville and FiberMax varieties and for downstream application. Aeris extends broad-spectrum protection against insect pests such as cutworms and thrips as well as reniform and root knot nematodes. Aeris offers growers two effective modes of action against thrips to ensure protection and manage resistance development.
A nematicidal seed treatment by Bayer, COPeO™ Prime, increases cotton plant vigor by protecting the plant from root-damaging parasitic nematodes to provide a healthy start to the growing season. COPeO Prime has shown to bring additional yield both with and without the use of other nematode control measures such as variety resistance and other nematicidal seed treatments. Improved nematode protection and even higher overall yield potential is achieved when pairing COPeO Prime with Aeris® insecticide/nematicide seed treatment by adding a second effective mode of action for reniform and root knot nematodes.
An in-furrow, at-plant product, Velum® Total insecticide/nematicide delivers wide-spectrum, long-lasting control of nematodes and early-season cotton insects, including thrips, aphids and fleahoppers. The combined strength of two active ingredients delivers pest control, promotes earliness, maximizes yield potential and can suppress diseases such as Fusarium wilt. The higher the pest pressure, the greater the impact on yield. Plants treated with Velum Total have healthier roots, exhibit strong early-season growth and stay healthier through the season. The innovative formula allows for variable rate and site-specific application, increasing opportunity for profit through customized treatment.
When insect population levels warrant foliar insecticide applications, cotton growers can choose from Baythroid® XL and Leverage® 360 insecticides. Baythroid XL, a pyrethroid, performs on a broad spectrum of insect pests, with fast knockdown and long residual control. Leverage® 360 with Stress Shield™ protection enhances a crop’s ability to handle a variety of abiotic and biotic stresses, such as stink bugs and bollworms, thereby maximizing yield potential. Its two modes of action offer rapid knockdown and residual protection. Application timing should be based on careful scouting and local economic thresholds.
Visit our cotton section for more information about insect control options, seed treatments, in-furrow insecticides, foliar insecticides and FiberMax and Stoneville varieties, or contact your local Bayer representative.
*Please read the entire label for the best possible results and to confirm that the product is effective on the pest you need to control. Not every product is suitable for every situation nor registered for use in every state, and correct application techniques will ensure the best results. Baythroid XL and Leverage 360 are Restricted Use Pesticides.