Northwest Plains
Pest Management News
Volume 1 Issue 5
Bailey and Parmer Counties
July 12, 2002

Current Crop Conditions

Irrigated cotton in progressing very well. There are any where from 7 to 10 nodes above white flower. Cotton that has not started blooming to date have 10 to 15 total nodes. With this kind of vigorous growth the height to node ratio (internode length) needs to be monitored closely, we don't want it to get out of hand.

Most corn is silking and well into pollination. Growing conditions have been very good to this point as indicated by the height of the plant. Some fields are so tall they are dragging the truss rods on the center pivot. Corn is at peak water use.

Daily Water Requirements

Crop
Inches Per Day
Cotton
.20-.25
Corn
.30
Grain Sorghum
.18-.22

Southwestern Corn Borer

Southwestern corn borers have been found in numbers that warrant treatment south of Springlake. Historically that area is the first to be treated.

Heat Units
Current
2001
Corn (April 1st planting)
1877
1812
Cotton (April 20th planting)
914
846
Cotton (May 1st planting)
885
809
Cotton (May 15th planting)
820
751

Check for egg masses to determinethe potential infestation and the correct timing of insecticide application. Insecticide should be applied when 20 to 25 percent of the plants are infested with eggs or newly hatched larvae.

Excessive Cotton Growth

What is excessive growth? Excessive growth is loosely defined as when the average length of the top five internodes is greater than two inches. The need for a growth regulator (mepiquat cloride, Pix) on cotton needs to be evaluated carefully. Cotton is easier to manage before growth gets out of hand. Applications of mepiquat cloride suppress cell enlargement and promote shorter internodes, thus shorter more compact plants. Do not only consider current conditions, look ahead. Ask yourself some questions: How much moisture is in the soil profile now? Can irrigation keep up with demand? How did the crop grow off in the past? What variety is planted? What is my fruit load?

1

 

If the answers to the questions above indicate thepotential for excessive plant growth then an application of mepiquat cloride may be needed. Application rates of mepiquat cloride increase with growth potential and the overall size of the plant.

Predators

Adult damsel bugs are 3/8 to 1/2-inch long, tan to reddish brown and slender, with the body tapering toward the head. Nymphal stages are similar but lack fully developed wings. Legs are relatively long with the front pair enlarged slightly to capture prey. The head bears long four-segmented antennae and a four-segmented beak. The beak is held underneath the body when at rest but is capable of being extended to pierce prey. They feed on caterpillar eggs, small larvae, aphids, fleahoppers, lygus bugs, and spider mites.

Boll Weevil Eradication

No boll weevils were caught north of Hwy 145, 8183 traps inspected. One boll weevil was caught south of Hwy 145, 11858 traps inspected, with 68.3 acres sprayed. Failed cotton must be kept non hostable the rest of the season to avoid the TBWEF assessment.

Trapping
Beet Armyworm
North of Hwy 145 907 in 23 traps
South of Hwy 145 30 in 25 traps
Corn Earworm 614 in 6 traps

 

Monti Vandiver
Extension Agent-Integrated Pest Management
Texas Cooperative Extension
401 3 rd Street
Farwell, Texas
806-481-3300
Educational programs conducted by Texas Cooperative Extension 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 Texas Cooperative Extension is implied.
The Texas A&M University System, U.S. Department of Agriculture, and the Commissioners Courts of Texas Cooperating
2