“Spend Money to Make Money”
is Best Guide for Cotton Insect Control

Writer: Tim W. McAlavy, (806) 746-6101, email: t-mcalavy@tamu.edu
Contact: Jim Leser, (806) 746-6101, email: j-leser@tamu.edu

LUBBOCK – 2002 holds many uncertainties for South Plains cotton growers...from the pending farm bill to the ever-present threat of crop-damaging insects. As a result, growers should adopt a “spend money to make money” approach to pest control, said a Texas A&M cotton entomologist.

“Ask yourself...will it pay? Will the control application return a profit through higher lint yield? Then ask yourself...is there still time to make the application successfully,” said Jim Leser, Texas Cooperative Extension cotton entomologist based at Lubbock. “Timing is everything in making the application work, and in making more profit to pay for the control cost.”

Growers who know how to key insecticides to the pest(s) at hand, know the hot spots in their fields, understand population thresholds, and manage their crop to avoid catastrophes are one step up on a good crop.

“Don’t use the highest labeled rate to control a pest. This will get the targeted pest, but it will also take out the beneficial insects that feed on other pests and it can sometimes cause a later flare-up of secondary pests,” Leser said. “Be selective in your chemical treatments. Target the pest with the right chemical.

“And watch your fields closely. It’s very important to scout for square-stealing pests at least two weeks past bloom initiation. That is the critical time for yield loss. Scouting and watching your fields can also improve your late-season management. After the cotton crop has ‘cut-out’ and received an additional 350 to 450 heat units, we can quit spraying for pests completely. Knowing how to recognize that stopping point will save dollars on unnecessary late-season bollworm and plant bug applications.”

Growers who understand treatment thresholds, the guide numbers that trigger economical pest control applications, will also learn to “let the small stuff go,” the entomologist added.

“Spray only when it’s necessary...when pest populations have reached a threshold that indicates economic damage will follow. Avoid knee-jerk spraying that can harm “beneficials” such as lady beetles, spiders, and minute pirate bugs,” he said. “In order to keep those good insects alive in our crop, we have to allow a certain level of pests to exist out there as food.

“Early scouting/monitoring keeps us in touch with beneficial insects and the pests (stressors) that we need to keep an eye on. It is a good tool to improve our pest control decisions and our long-term management.”

Thrips are one of the most important early-season pests to watch for in irrigated cotton. Growers
seldom increase yields by controlling thrips in dryland fields where water is the major limiting factor, the entomologist noted.

“Western flower thrips are the chief culprit on the Texas High Plains. Their feeding damages both leaves and squares on the plant. Research studies have shown that we can boost yields by as much as 21 percent if we control early-season thrips,” Leser said. “We can achieve good control by putting Temik down at planting.
Or we can make one or two timely applications of Orthene, Bidrin or dimethoate later -- as thrips move into the field. The new seed treatment Cruiser also looks promising.”

When it comes to other cotton pests, Leser said he expects to see low populations of boll weevils, bollworms, and beet armyworms during the 2002 cotton season.

“That’s just my own take/prediction for this season. Regardless of which pests they face, growers who base control decisions on a realistic target yield, and then spray to make money instead of simply spraying to eliminate pests, will come out ahead,” he said. “Spraying late is not profitable. The best bet is to protect against early-season pests, and then manage the crop for an early harvest.”

Brand names appearing in this article are used for product identification. No endorsement is intended, nor is criticism of similar products not mentioned.