Moisture conditions continue to improve across much of the area. Thunderstorms Sunday evening, Monday and Tuesday dumped much needed rainfall across the Concho Valley. Unfortunately, it also brought with it a hailstorm that covered several miles in Tom Green County. It started at Fairview School and moved Northeast for several miles. Cotton was stripped of leaves in many fields.

Cotton has made a lot of progress the past ten days and prospects for an above average cotton crop is in the making. Insect pressure dropped off last week and generally has been pretty quiet this week. Producers should expect another bollworm egg lay within the next week or so. Bollworm trap catches increased Monday in Tom Green County but remained low in Runnels County. Wednesday trap catches dropped back down to lower numbers. This is a good sign. I would certainly like to get well into August without having to deal with Bollworms / Budworms again. The Blacklands reported control problems using pyrethoid insecticides and after inspecting the treated cotton fields they found the larval infestations to be tobacco budworms. We will keep a close eye on the situation.

Grain sorghum harvest has begun and bushel weights are excellent and yields are very good.

Bollworm egg and larval counts were very low this week. Actually all insect counts were low primarily due to adverse weather conditions. I am sure this situation will change shortly so scout your fields closely. Our primary concerns from now on are cotton aphids and bollworms. Bollworm survival will be much higher now because of the larger plant canopy, higher humidity in the plant canopy and the abundance of fruit on the plant. Looking on the good side of things, the natural enemy populations are also increasing significantly which will help reduce any potential pest problems.

Many producers are concerned with rank plant growth with the good moisture conditions we have in some areas. Remember most dryland cotton has little to no fertility under it and most of these fields are approaching or is at the bloom stage. From first bloom until ten days after pink bloom, the cotton plant is using almost 4/10 of a inch of water per day.

PLANT GROWTH & DEVELOPMENT
(Bloom to Open Boll) We are also running out of time to set a crop. Remember, it takes 21-23 days to go from pinhead square to bloom and we need a bloom by the 1st of September to be assured of a harvestable boll. (Do not expect or bank on another fall like last year). The June 19-20 planted cotton which received severe hail damage this week is going to have a tough time making an average crop. Basically under normal conditions our crop is set by August 8-10.

The wide range of rain received this year complicates many management decisions. Some producers are needing to apply additional nitrogen and the best method to do this after blooming begins with a foliar application. Urea is used by a number of producers for this purpose and their primary question is how much? The cotton plant can absorb about 5 to 6 pounds of nitrogen per application. So a producer would be applying 10-12 pounds of urea per acre. If a higher rate of nitrogen is applied, leaf burn can be expected.

Grain Sorghum

The late-July rains may delay harvest in some of the early planted fields. Due to the drought stress suffered at the first of the season by these plants, the potential for Charcoal Rot will be high; particularly in hybrids that are susceptible. Early planted fields should be harvested as son as the grain moisture is low enough for storage/selling purposes. Long delays will see plant lodging of 10 percent or more.

WHEAT CONFERENCE

A lot of planning has gone into developing the 2002 Big Country Wheat Conference to be held in Abilene, Texas on August 22. There are a number of excellent speakers on the program and it will be worth your time and effort to attend.

By the time a boll reaches peak carbohydrate demand it is usually buried in the canopy and the leaves surrounding it are in dense shade. Bolls in this position bust rely on leaves farther away at the top of the plant for carbohydrates. Water stress, cloudy weather and nutrient deficiencies can all decrease photosynthesis and therefore reduce the carbohydrate supplying the power of the plant.

First bloom is a good time to evaluate the overall status of the plant. At 7 to 14 days after first bloom, check square retention and the number of nodes above white flower (NAWF).

NAWF at early bloom will vary, depending on management and the level of stress encountered by the crop. NAWF provides a good estimate of the potential boll sites. Studies conducted in the Coastal Bend indicate that crops produce average yields if they retain 60-70 percent of first and second position fruit (squares, flowers and bolls). Table 6.2 below shows potential management guidelines for cotton production in the Coastal Bend based on fruit retention. Drought, disease and pests can reduce terminal growth and NAWF at early bloom. Insects that remove squares, such as cotton fleahoppers and Lygus bugs, may actually increase NAWF at early bloom.

To determine NAWF, count the nodes above a first-position white flower. If the NAWF count at early bloom is below seven, the plant may reach cutout prematurely unless the plant stress is relieved. Much of the dryland production in the western part of Texas enters early bloom at this stage. To maintain growth, producers mush carefully manage inputs. An NAWF count above 10 at early bloom may indicate reduced fruit retention or rank growth. You will need to monitor the fields continually to determine the proper management strategies. A rapid decline in NAWF can be good or bad. It may signify excellent boll retention and high demands for nutrients and water. However, it may also indicate severe drought stress, which should be alleviated with irrigation where possible. If NAWF remains above 10 or increases rapidly, a more significant problem may exist. This indicates that there are not enough bolls to prevent additional terminal growth. You will need to respond immediately to avoid rank growth and delayed maturity.

The plant continues to add squares and develop bolls at early bloom. The ovary (where the seed develops) is compound in domesticated cotton. A Pima cotton ovary averages three to four carpels (sections) or locules (locs) per boll. An upland cotton ovary averages four to five locs per boll. The number of locs is determined early in square formation (3 weeks before flower opening).

A cotton flower opens in the morning and then sheds its pollen. Cotton is generally considered a self-pollinating plant (if there are no insects, 95 to 99 percent of the flowers are self-pollinated). Cotton pollen is sensitive to moisture and can rupture upon contact with water (rainfall or irrigation) within 30 to 60 seconds.

The cotton fibers begin to elongate from the surface of the ovule (unfertilized seed) and can elongate for a few days even if the ovule is not fertilized. The unfertilized ovules are called motes.

Fiber initiation is sensitive to temperature. Hot weather during initiation produces shorter fibers, fewer seeds per boll, smaller seeds and smaller bolls. An average seed has 13,000 to 21,000 lint fibers, and the average loc has six to nine seeds.
Young seeds produce hormones that increase the flow of nutrients and carbohydrates to them. Bolls that produce fewer than 10 to 15 seeds are not strong sinks and are ultimately shed. High temperatures are the major cause of low seed counts.

As the fiber is lengthening and the seed expanding, the boll wall enlarges. The boll reaches maximum size and fiber reaches its maximum length in about 20 days. A lack of potassium or water can limit boll size, seed size and fiber length.

During the remainder of boll development micronaire, maturity and strength are determined. Cellulose is laid down in winding sheets around the inside of the cotton fiber. Warm weather favors cellulose deposition and may increase micronaire values. Cool weather reduces cellulose deposition and can reduce micronaire values.

Fiber strength is related to the average length of the cellulose molecules deposited inside the cotton fiber. The longer the cellulose chains, the stronger the fiber. Genetics controls about 80 percent of strength development, although environment does have some influence. Excessive weathering and over-ginning can weaken fiber.

Seed quality is determined in the later stages of development. Seeds reach maximum size 4 weeks after pollination. After day 25, the embryo begins to accumulate protein and oil. The same factors that decrease the maturity of the fibers also lower seed quality.

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.

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

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