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June 1, 2022
The first five to six weeks of cotton plant growth helps set the stage for crop earliness and yield potential.
“We manage cotton for earliness. To achieve that, you’ve got to have a lot of things go right in the first 40 days,” says Hank Jones, an independent crop consultant and owner of RHJ Ag Services in Winnsboro, Louisiana. “Foundationally, that first 40 days is about developing healthy root systems, controlling weeds and managing for earliness.”
Managing for an early harvest requires setting early squares in the prebloom period without damage from thrips and tarnished plant bug. Left untreated, the pests can delay crop maturity.
That has not always been the case. Primary cotton pests have changed over the years along with technology. Two decades ago, bollworms and boll weevils were the primary threat to early season crop management. As seed technology improved, genetic resistance lessened that worry, and the primary pest control focus has shifted to the tarnished plant bug.
“Poor tarnished plant bug control delays the fruiting cycle, shifting it later in the season. That can result in rank plant growth,” Jones says. “Everything is foundational in that first 40 days. If you are losing fruit, you are delaying the crop, but if you can get the first six weeks of the season right, you won’t be fighting to make a late-season crop.”
Controlling cotton aphids and tarnished plant bug populations is critical to managing earliness. Early maturing cotton also is more likely to escape damage from late-season pests.
“Cotton aphids, if they get established, can really hurt a cotton crop. Transform is the only thing we know will be effective. That’s our go-to product,” Jones says. “It’s also wise to get Transform out during the prebloom stage to ensure we’re getting tarnished plant bug control. Put your best products out when you are trying to make a high-yielding cotton crop.”
While a sweep net is an effective tool when scouting for tarnished plant bug adults, experts suggest also using a drop cloth to monitor nymph populations, especially at and after bloom begins. Ideally, field scouting is done twice weekly to ensure optimum square retention.
Mississippi State University recommends using an economic treatment threshold, before first square, of one or more tarnished plant bugs per 10-row-feet.
During the first two weeks of squaring, an insecticide spray is recommended if one or more tarnished plant bugs are collected using a drop cloth within 6-row-feet, or eight are found in 100 sweeps.
From the third week of squaring through bloom, that threshold increases to three tarnished plant bugs per 6-row-feet using a drop cloth, or 15 tarnished plant bugs per 100 sweeps.
Once cotton reaches cutout, which is defined as node above white flower (NAWF) five plus 350 heat units, the plant has reached the stage that pest damage is less likely to cause yield loss. This usually occurs around the sixth week of bloom.
“Cotton is such a long-season plant that I’ve seen some rough starts end well but managing for earliness is always better,” Jones says.
In addition to treating pests with insecticides only when economic thresholds are met, managing for resistance is another critical component to Integrated Pest Management.
Because university entomologists have documented pyrethroid-resistant and organophosphate-resistant tarnished plant bug populations, rotating modes of action is critical to managing further resistance development.
“We recommend rotating modes of action rather than using the same class of chemistry to control subsequent generations of aphids or tarnished plant bug,” says Nathan Alonso, insecticides product manager, Corteva Agriscience.
To learn how Transform® WG insecticide with Isoclast® active can help you harvest an earlier cotton crop, visit corteva.us/TransformWG.
™ ® Trademarks of Corteva Agriscience and its affiliated companies. Isoclast is a registered active ingredient. Transform WG is not registered for sale or use in all states. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. Always read and follow label directions. © 2022 Corteva. CA14-396-031 (05/22) BR CAAG1TFRM054
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