Last fall, Lower Rio Grande Valley farmers voted to be part of the Texas Boll Weevil Eradication Foundation. Out of 17 zones in Texas, the Lower Rio Grande Valley was the next to last zone to do so. (Northern Blacklands came in about a month later.)

Holding Rio Grande farmers back was memory of an eradication program some years ago that many producers felt brought more problems than it solved. Also, being in close proximity to Mexico, many felt efforts on this side of the border were of little use when Mexican farmers seemed to be doing nothing. And farmers must dig deeply into their pockets to fund eradication: $28 per acre for irrigated land, $14 for dryland cotton.

But times have changed: Mexico now has an eradication program of its own and Rio Grande Valley farmers realize they have to band together to go after the boll weevil. They figure money they spend to get into the program they will recoup easily considering the damage done by the weevil and the cost of insecticides they applied to control it.

Manda Cattaneo, the Cotton Integrated Pest Management Entomologist at Texas A&M Agricultural Research and Extension Center in Weslaco, has high hopes for the eradication program. “It will make a big difference by lowering the weevil population for next spring,” Cattaneo says. Spraying didn't take place until the end of June when cotton was at 10 percent cracked bole. This is the way the program was designed to work.

Michael O'Connor, from the Texas Boll Weevil Eradication Foundation, says the program begins slowly. “In the first year, we don't begin spraying until late in the season to avoid problems with secondary pests. The goal is to reduce significantly the number of weevils that will diapause and re-emerge to damage the following year's crop.”

Yield gains

He says many growers report increased yield because diapause weevils do not feed on top bolls.

In the future, eradication will eliminate insecticides for boll weevils and drastically reduce use for other insect pests.

The eradication program operates through mapping, trapping and control. A Global Positioning Satellite system helps map all fields in a zone. Weekly monitoring of boll weevil activity in traps placed around the mapped fields is key. Besides a pheromone that attracts the insects, traps include an insecticide strip so that the trap not only determines weevil population, but also acts as a control.

Early planting and harvest, timely stalk removal and insecticide application make up the control phase. The foundation applies Malathion ULV, 12 ounces per acre weekly during the diapause stage. In subsequent years, trap catches determine spray schedules. Spraying will begin when cotton reaches pinhead square and will continue until harvest or the plant is killed with defoliants or desiccants. Stalk destruction also is mandated.

Most spraying is by aerial application. Applicators use ground rigs when aerial spraying is not feasible. The program takes great care to confine spraying to target fields and to protect beneficial insect populations and honeybee hives.

4 to 6 years

It takes about 4 to 6 years to confirm eradication in a particular zone. Areas with less weevil activity may reach eradication earlier. The Texas Department of Agriculture (TDA) has developed guidelines to determine when an area qualifies for a declaration of eradication.

TDA is responsible for oversight of the Texas Boll Weevil Eradication Foundation operations. TDA also sets the assessment each year. Growers supply most of the funds for eradication. State and federal cost-share provides the rest.

Experts estimate Valley cotton acreage about 20 percent down from last year's 207,000 acres.