Grain sorghum harvest has begun and yields are good as well as the price for the grain.

Cotton continues to progress rapidly and conditions vary greatly from Winters/Wingate to Miles/Mereta to Wall/Vancourt communities. Bollworm infestations are the major topic of concern right now. Heaviest infestations are in the Miles, Mereta, Veribest and Wall communities. It is very important to monitor your cotton fields closely for bollworm infestations. I have been discussing IPM Basics in each newsletter this year and I don't think everyone is reading it or is understanding it very well. It is not time to treat just because you or your scout has found some worms feeding in white blooms or found a flared square here and there. IPM tolerates some damage, low levels of pests in the field, uses economics for a basis, uses thresholds, etc. Why scout and worry about what's out there if you can't tolerate some damage? (Sorry it has been a long week.) Also keep in mind, many dryland cotton fields have way more fruit set than can be matured out.

Therefore, a little worm damage can be tolerated especially when soil moisture is limiting and fertility is low.

Much of the cotton in the Concho Valley is in physiological cutout (3-4 NAWF). The cotton crop in most areas, with the exceptions of Wall (South and West ) and Wingate, have an above average crop set and looks great. The bollworm egg-lay continues and larval counts continue to increase across the area. Bollworm infestations are heaviest in the Miles and Mereta communities right now but everyone should be scouting closely for worm infestations.

Bollworm management requires good scouting practices and common sense control decisions. When I scout for bollworms, I check whole plants scattered throughout the whole field not just terminals or white blooms in one spot in a field. In selecting plants for monitoring, it is important to recognize that the taller more dominate plants tend to have higher numbers. Sometimes this can be used to your benefit if you check only these plants but adjust your threshold to reflect the disproportionate number found on these tall plants.

The minimum plant sample size should be 25 plants per field. Forty plants are ideal but time consuming. The scouting program uses the 40 whole plant counts and looks in 13 different areas of each field. Spend most of your time in marginal fields, those fields near threshold. The least amount of scouting time should be spent in fields that are obviously overrun by worms or are virtually devoid of worms. Check plants by starting in the terminal and working your way down the plant. Dissect open the terminal whorl. Also open all blooms, square and boll bracts. By the time you're done, the plant should have sustained some physical damage.

When I check a plant, I am looking first for two things—eggs and damage. I usually find the evidence of caterpillar feeding long before I find the actual worm. If one looks very carefully, you probably will find a very small worm near the damage. That is, if it isn't old damage or large damage. Sometimes you won't find the worm. If so, hopefully it is because a beneficial insect nabbed it rather than it being the result of your poor eyesight. The key to good bollworm scouting and control decisions is finding the eggs and the very small caterpillars (1/4" or smaller).

Eggs are found in many locations including but not restricted to the upper surfaces of the newer leaves, leaf petioles, bracts and flowers.

Eggs hatch in about three days and are pearly white until before hatch, when they turn brown. Black eggs can mean that they have been parasitized by a wasp. Newly emerged caterpillars are about 1/16" long and almost colorless with the exception of their black head. Once they feed, they will be colored in various shades of yellow, red, brown or black. Over a period of about two weeks, these caterpillars will feed on increasingly larger fruit until about 1 ½ to 1 5/8 inches long, at which time they drop to the ground and pupate.

While I previously mentioned that our cotton guide lists 5,000 worms per acre as our treatment threshold, I must emphasize that these are small worms, not the 1" snakes some folks find. I also must point out that this threshold is for individuals that have a hard time locating small caterpillars. If you have the experience or ability to easily find the 1/16 to 1/4" worms then you must adjust your threshold upwards.

If treatments are necessary, good coverage is very important. Plant canopies are very large and most larvae are down in the plant canopy. The use of hollow cone nozzles is recommended and gallon usage should be around 8-10 gallons per acre by ground or at least three gallons per acre by air. Good penetration into the canopy is very important. Use a mid to higher rate of insecticide to insure good control and provide an adequate residual.

I have been noticing a few beet armyworm and fall armyworm larvae feeding primarily in blooms for several weeks but no big numbers. Nothing to worry about right now. Pheromone trap catches remain very low. Stephen Halfmann has been finding a few as well and we will continue to watch closely and keep you informed of what's happening.

The Runnels County Farm Service Agency, Natural Resource Conservation Service, and Texas Cooperative Extension will host a farm bill program on Thursday, August 22. Three meetings are scheduled in Runnels County for the day. Meetings will be held at the following locations; at 9:00 a.m. in Wingate at the Wingate Lions Club Building, at 1:00 p.m. at the SPJST Hall in Rowena, and at 6:00 p.m. in Weatherby Hall in Miles.

This meeting is an update on the new Farm Bill and the interpretations of this bill by the Farm Service Agency and how it will affect Runnels County producers.

I think this program has been very useful and successful this year for cotton growers throughout the Concho Valley. The information collected has gone into daily insect updates, weekly turnrow meetings, weekly newsletters and provided local gins with weekly information. As usual, the scouts will be leaving to go back to school but there's not a lot I can do. Our crop season hits at a bad time for employing students during the growing season. They have done an excellent job and should be commended for a job well done.

DNA Offers Clues to Battle Invasive Trees
written by
Okla Thornton
Manager, CRMWD

Seattle, Washington, August 13, 2002 (ENS)- A Washington University professor and her graduate students are tracing the DNA of invasive Tamarix plants to learn which biological controls might work best to battle the nonnative trees. Earlier, Department of Agriculture studies show that an Arizona Tamarix, commonly known as tamarisk or saltcedar, will not be eaten by certain Asian insects known to like saltcedars. These insects prefer plants that grown in Texas or New Mexico, showing that there are different kinds of the plants in different areas.

Dr. Barbara Schaal, a Washington University professor of biology, has shown that two of the introduced species of Tamarix have interbred to create a hybrid that may be resistant to biological control agents now being developed.

Saltcedars, first introduced to the United States in the 1800s for shade and erosion control, have since invaded the arid southwest and are contributing to the drying up of creeks and streams in that water threatened area. More than a million acres are now infested with saltcedar along streams and riverbeds.

The salt cedar's long taproots suck up salty groung water and drop salt crusted leaves on the soil surface. This makes it almost impossible for native plants to take root. The loss of native plants also decreases the insect and bird biodiversity.

Schaal's graduate student John Gaskin has used DNA sequences to identify which species are here and to document hybridization. Their DNA analyses also helps them pinpoint where the plants may have originated in Eurasia.

So far Schaal and Gaskin have found that the most common invasive here is a hybrid of two species that do not grow in the same areas of Asia, forming a novel plant genotype. These results will help federal researchers determine which insects they could import to help control the invasion.

Schaal and Gaskin caution that any novel hybrid plants may prove to be unpalatable to species specific insects, since they did not evolve with them. Their results appear in this week's issue of the journal "Proceedings of the National Academy of Sciences."

More information on Tamarix is available at :
http://www.invasivespecies.gov/profiles/saltcedar.shtml

A lot of planning has gone into developing the 2002 Big Country Wheat Conference to be held in Abilene, Texas at the Abilene Civic Center on August 22. There are a number of excellent speakers on the program and it will be worth your time and effort to attend. For more information, please contact the Taylor County Extension Office at
915-672-6048.

The "IPM Updates" continue and is doing very well. There have been lots of callers listening to the daily reports. The telephone number to call is 365-2642. This update will give producers a general insect and crop report for the different areas in Runnels, Tom Green and Concho Counties that is being monitored by the cotton scouts. I would encourage you to use this service. This allows you access to the information at your convenience. If it is not used this year, we will discontinue it next year.

County Tom Green BUDWORM/BOLLWORM MOTH TRAPS

Traps were baited May 16, 2002 - rebait every two weeks

County Runnels BUDWORM/BOLLWORM MOTH TRAPS

Traps were baited May 16, 2002 - rebait every two weeks

BE LOOKING FOR INFORMATION IN THE PEST MANAGEMENT
NEWS ON THE COTTON TOURS COMING UP NEXT MONTH.

Educational programs conducted by the Texas Agricultural Extension Service serve people of all ages regardless of socioeconomic level, race, color, sex, religion, handicap or national origin. The information given herein is for educational purposes only. References to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the Cooperative Extension Service is implied.