Insecticide Resistance Management--1993 Recommendations Bollworm/Budworm - Southeast

Ron H. Smith


 
ABSTRACT

We do not have a resistance management plan for the Southeast that has been published in the ag media, but all extension entomologists individually are promoting resistance management practices that are in the best interest of growers in each State and region.

All extension entomologists in the Southeast (Smith and Freeman-Alabama; Sprenkel-Florida; Lambert-Georgia; Roof-South Carolina; Bacheler-North Carolina) are in close agreement on what current approaches need to be. However, there is no unified plan among the states.

In reality, we may have more diversity in our region than the mid-south does. Examples are: North Carolina, where they get one big flush of corn earworms from corn; the coastal plains Georgia where a tremendous diversity vegetables occurs--and cotton even comes back from the previous years stubble; to the Tennessee Valley area of north Alabama where cotton is the dominant crop, much like the mid-south. Speaking of the Tennessee Valley area of Alabama, where about 236,000 acres of cotton are planted, vial data indicates that resistant genes do exist - the only thing that has prevented control problems in recent years is the lack of high pressure.

I am pleased to see the mid-south now has a resistance management plan that encompasses all cotton pests and all classes of chemistry. While the mid-south entomologists were promoting alternative chemistry a few years back several southeastern entomologists were promoting the use of beneficial insects, ovicides and potentially the Bt's in the early season window. We knew early-on that we had to manage beet armyworms and aphids along with the bollworms and budworms. In fact, the budworm was, and may still be, number three on the list of insects to manage for in cotton in the southeast.

Fortunately we manage resistance-for all of these pests by many of the same practices. 1. Earliness (incorporating all practices that enhance it). 2. Utilization of naturally occurring parasites and predators in early season. Accepting low levels of damage to give beneficials time to work. 3. Use of ovicides for the early season window. 4. Soft early season chemistry (such as the Bt's). 5. Selective rates for pests such as the tarnished plant bug. 6. Discourage the use of pyrethroids for thrips, plant bugs, weevils and other early season pests. 7. Use of thresholds, timely applications, good coverage and twice/week scouting for mid-season bollworms and budworms. 8. Use of pyrethroids after first bloom based on factors-listed in number seven. 9. Time pyrethroid applications for small larvae or about-to-hatch eggs. 10 Tank mix ovicides with pyrethroids during midseason when egg counts are high. 11 Alternate to phosphate/carbamate chemistry in mid-to-late season when the armyworm complex (FAW/BAW) becomes the dominant target pest.

In summary, we hope to delay problems with tobacco budworm resistance over much of the southeastern cotton growing area for the foreseeable future.

We are not talking about the small acreage of cotton that the southeast planted a few years back - we are now planting about 1 1/2 million acres and harvesting up to 2 million plus bales.

Since the boll weevil has been taken out of the system over much of the southeast, we have some distinct advantages of growing cotton over many (maybe even most) areas of the cotton belt. For the past two seasons we have had adequate moisture and produced 800-1400 lb. yields with only a total of 2 to 5 insecticide applications.

Having the weevil out of the system is a great help for us in designing resistance management plans and we are optimistic about the potential for cotton in the southeast at present and also about being able to handle our pest problems in the near future. It is an exciting time to be an Extension cotton entomologist in the southeast and have the first opportunity in 80 years to redesign IPM strategies in the absence of the boll weevil.



Reprinted from 1993 Proceedings Beltwide Cotton Conferences pg. 29
©National Cotton Council, Memphis TN

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Document last modified Sunday, Dec 6 1998