Much of the area received from 1" to 7" inches of rain last week and crops have really responded to the improved moisture conditions. So Has The Weeds. Two weeks ago, our philosophy was to be very conservative in dryland cotton fields and today that philosophy has changed 180 degrees. It's time to load it up where adequate rainfall has occurred. Insect activity has exploded over the past week and producers are encouraged to monitor cotton fields closely for cotton aphid and bollworm infestations. Many cotton fields have required insecticide treatments for aphids. Bollworm trap catches jumped up late last week and egg counts range from zero up to 152% this week. Many fields have egg counts well over 100 bollworm eggs per 100 plants at this time.

Grain sorghum looks great in most areas, especially in the Lowake, Miles, Ballinger, Eola and south of Mereta communities. Not a lot of insect pressure in sorghum and many fields are in the hard dough stage.

Cotton aphids have exploded across the area and producers are encouraged to scout their fields regularly. We have not had this problem in several years and, even in the years where aphids have been a problem, it was later in the season. Stunting of plants is already visible and infested areas are getting bigger daily. This small cotton cannot tolerate this level of infestation for very long. The economic threshold is really based on cotton that is in the bloom to boll stage and it states "Insecticidal control of cotton aphids should be delayed until infestation exceeds 50 aphids per leaf." We exceed this level in many fields. Cotton, which is in the matchhead square stage, cannot tolerate this level of infestation very long.

Natural enemy numbers are not at population levels in cotton right now to keep aphid numbers down below economic thresholds. Insecticides recommended for cotton aphid control include:
Bidrin® @ 6-8 ozs./acre,
Centric® 40WG @ 2 oz./acre,
Intruder® @ .6 oz./acre,

Provado® 1.6F @ 3.75 oz./acre or Trimax® 4F @ 1.5 oz./acre. Coverage is very important with all these products. Do not use a sticker additive with these materials because it will reduce the uptake into the plant.

Bollworm egg counts range from 0-152% this week. We have not seen this in several years. Worm damage can be found in some fields but larval counts remain very low. This is usually the case; eggs hatch, larvae feed for a short time and die. Natural mortality is usually very high in small matchhead square cotton. As cotton nears bloom and develops more of a canopy, survival and damage levels increase. This egg-lay should be monitored closely for the next 5-7 days. If a heavy egg-lay exists in your field, and you're having to treat for cotton aphids, it might be to your advantage to add an ovicide such as Larvin to your tank mix.

Most cotton fields in the Concho Valley have past the window of opportunity to apply glyphosate over the top. It must be post-directed or use a hooded sprayer at this point in time. The other option would be to use another chemistry. We will discuss this in a minute. Monsanto or any other company is not liable or responsible for crop damage caused by late glyphosate applications. Late applications (after 5th true leaf) causes sterility of the fruit. Square formation and square retention will continue at a normal pace until it blooms. Glyphosate causes sterility and sometimes deformed anthers within the bloom.

The bloom contains both male and female reproductive parts and fertilization occurs within the individual bloom. Once the square reaches bloom, it will usually abort within a week or so because it was not fertilized. It is unknown how many fruiting forms will abort and there are probably many factors which determine the amount of crop damage caused by late glyphosate applications.

Now we can discuss other options for weed control. For grass control, we still have Assure II®, Fusilade®, Select®, and Fusion® which can be applied over the top of cotton at any time during the season. For broadleaf weed control, Staple® can be applied over the top and does an excellent job on pigweed. All these herbicides work best when weeds are small and actively growing. They are certainly actively growing right now.

New Insecticides for Cotton

Centric (Syngenta) and Intruder (Aventis CropScience) have received labels for certain cotton insect pests. They are labeled for aphids, thrips, tarnished plant bugs, whiteflies and cotton fleahoppers. Experiments across the cotton belt have shown these products to be effective against the listed pests. Both products are of neonicotinoid chemistry similar to Provado, Admire, Gaucho, Trimax, Prescribe and others and use rates for aphids are in the $5-$6/acre range.

^a Test conducted by A.N. Sparks, Jr. and J.W. Norman, Jr.
^b Treatments were applied on 5/8 by CO2 pressurized backpack sprayer, 3 TX5 hollow cone nozzles/row (1 over top, 2 on drops), 40 psi, and 10 gpa total volume.
^c DAT = days after treatment

Once fruiting begins, growers have to make many management decisions. Squares form at the first axillary bud after the first fruiting branch develops. The location of the node is determined by the cotton variety and environmental conditions during the first weeks after emergence.

After the first three weeks of plant growth, the only way to increase the number of squares is to protect against pests and to sustain plant growth, which produces sites for additional fruiting branches and adds fruiting sites to existing branches. Under optimum growing conditions, a new fruiting site will develop every 3 to 5 days moving up the plant and every 5 to 7 days moving horizontally along the fruiting branch.

In West Texas, fruit initiation usually occurs during warm temperatures and sunny days. The goal is to have 90 percent square set in the first week of squaring, 85 percent in the second week and 75 percent in the third week up to first bloom.

Fruit shed is unavoidable in the life of a cotton plant. It is caused by environmental, physiological and pest influences. Although growers generally view it as detrimental, some fruit shed is necessary, especially when the plant is adjusting its fruit load to accommodate growing conditions.

Fruit age sensitivity to shed.

Fruit shed is most harmful when cotton is planted late or during short growing seasons. Nonirrigated cotton has a higher risk of shedding because mid-season drought substantially reduces boll set.

A plant's response to fruit shed varies with local conditions and can vary from field to field. The most obvious symptoms are delayed flowering and increased vegetative growth. If fruit loss occurs early, more mid- and late-season bolls are often retained, but crop maturity will be delayed.

1) What pests are present, in what numbers and stages of development?

2) What conditions exist that may increase or decrease pest problems?

3) What natural enemies of the pests, such as parasites, predators, and diseases, are present that may play an important role in control?

4) What amount and type of damage is being caused or may soon be caused by pests?

5) What is the stage of development, condition, and value of the crop?

6) What is the potential for economical injury? How much damage is tolerable? Has the action threshold been reached?

7) What pest management options are available, and how do the advantages and disadvantages of each apply to the situation?

8) If alternatives are not available, is a pesticide treatment justified for the situation? If so, what is the material of choice?

9) If a pesticide is not justified, what approaches, if any, should be taken?

Field scouting and action thresholds can be used to provide much of the information needed to answer these questions. Thorough field scouting by an unbiased source who understands the crop and cropping system remains a major tenant of IPM.

The "IPM Updates" have begun. 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.

"Silver Leaf Nightshade"

Silverleaf Nightshade is a spreading to erect, rhizomatous perennial herb becoming woody with age. This species is found from Mexico, Arizona and Texas, north to Kansas and Missouri. It has been introduced eastward to Florida, Indiana and Ohio. The fruit of this plant is a berry 1-2 cm. in diameter. When immature, it is green with dark streaks from the top. When mature, the berries are yellow to yellowish-brown and are wrinkled. Each mature berry contains 40-120 seeds.

Poisonous Properties-As little as 0.1% of the animal's weight of silverleaf nightshade has been found toxic to cattle. The ripe seedpods are slightly more toxic than the green ones, and the leaves were least poisonous. The leaves and seedpods of silverleaf nightshade contain the poisonous alkaloid solanine.

Interesting note: It is reports that the Pima Indians use the crushed berries in making cheese.

Some fallow wheat fields have a healthy crop of volunteer RR cotton seedlings growing in them. The Boll Weevil Eradication program will have to monitor and trap these fields if the cotton is not destroyed soon. An assessment will be assessed if the field has to be monitored. You can plow these fields and destroy the volunteer cotton or, if your in a conservation tillage management situation, spray these fields with an herbicide to kill the cotton. Listed are some "Killing Products" to use on young cotton, ranked in order of preference. The growth stage of the cotton has a lot to do with the effectiveness of the treatment.

1. Banvel/atrazine-pre-flowering

2. Paraquat (Gramoxene Extra, Boa, Cyclone Max)-non-woody cotton

3. Buctril (if the plants are small)-pre-squaring

Paraquat alone will not kill RR-cotton if there is any wood in the plant. As you know, paraquat is a desiccant used at cotton harvest, and fixes and freezes leaves to the cotton plant. Regrowth will occur not long after treatment.

Remember, Banvel is a restricted herbicide and can cause problems to adjacent crops if physical drift occurs. Read and follow label recommendations closely. Those of you in the restricted zone in Runnels County are just out of luck using this product without a permit.

County Tom Green BUDWORM/BOLLWORM MOTH TRAPS
Traps were baited May 16, 2002 - rebait every two weeks

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