Howdy,
Next week we've got our field day coming up, check out our news release before the usual cotton update:
Wharton - AgriLife Extension to host Soybean and Cotton Turn Row Meeting – July 10th
By Corrie Bowen
County Extension Agent
Wharton County
Texas A&M AgriLife Extension, Wharton County Office will host a Soybean and Cotton Turn Row Meeting on Wednesday, July 10, 2019. The soybean turn row meeting will begin at 9 a.m. at the Howard and Dolly Wittig Farm in Lane City. You may have seen the soybean variety plot from Hwy 60 in Lane City. The soybean plot is located at the corner of Hwy 60 South and CR 122. The soybean plot is an exceptionally large variety trial, consisting of 47 replicated treatments. We’re certain to have a lot to look at. We’ll hear from Dr. Ron Schnell, our AgriLife Cropping Systems Specialist regarding soybean agronomics. Dr. Tom Isakeit will discuss diseases in soybeans. Following the visit to the soybean plot we’ll proceed to the Cotton RACE trial in Crescent.
The Cotton turn row meeting will begin at 11 a.m. in Crescent. The cotton variety trial is located 1 mile south of FM 961 on CR 461. If you are coming from the Wharton County Fairgrounds on FM 961 S heading toward Wharton, you’ll take the first county road to your right. Proceed one mile on CR 461 and the plot is on your right. We have a total of 10 cotton varieties in this year’s Replication Agronomic Cotton Evaluation (RACE) trial, plus two varieties selected by the cooperating grower. This is also a very large, replicated strip trial. The purpose of the RACE trial is to generate accurate, replicated yield data on commercially available cotton varieties for our area of Texas. Dale Mott, Extension Program Specialist for Cotton will discuss current observations in cotton research. Dr. Tom Isakeit will brief growers on cotton diseases and diagnosis for the 2019 crop as we progress toward harvest. We’ll plan to conclude the turn row meeting around lunchtime. 2 CEUs will be offered for TDA pesticide license holders and 2 CCA credits have been applied for. Please call the Extension Office by 12:00 p.m. on July 9 just to let us know that you’ll be attending. A flyer for the July 10th turn-row meeting is available at https://wharton.agrilife.org The flyer include maps and GPS coordinates for the two turn row meeting locations. I hope to see you there!
The members of Texas A&M AgriLife will provide equal opportunities in programs and activities, education, and employment to all persons regardless of race, color, sex, religion, national origin, age, disability, genetic information, veteran status, sexual orientation or gender identity and will strive to achieve full and equal employment opportunity throughout Texas A&M AgriLife. The Texas A&M University System, U.S. Department of Agriculture, and the County Commissioners Courts of Texas Cooperating. Individuals with disabilities who require an auxiliary aid, service or accommodation in order to participate in any Extension activity, are encouraged to contact the County Extension Office for assistance 5 days prior to the activity.
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This week I've noted beneficial numbers decreasing a little since last week, but still present in locations harboring low numbers of aphids still. We are seeing bollworm eggs, larvae, and damage in the following:
Wharton County
Cry1Ac + Cry1F + Vip3A near Danevang
0% bollworm eggs
2% bollworm larvae
4% bollworm damage
Cry1Ac + Cry2Ab near Blue Creek
0% bollworm eggs
0% bollworm larvae
3% bollworm damage
Cry1Ac + Cry2Ab near Blue Creek
0% bollworm eggs
0% bollworm larvae
5% bollworm damage
Cry1Ac + Cry2Ab near Blue Creek
0% bollworm eggs
0% bollworm larvae
4% bollworm damage
Cry1Ac + Cry2Ab near Crescent
6% bollworm eggs
2% bollworm larvae- one of those a 1/2" larvae
2% bollworm damage
Cry1Ac + Cry1F + Vip3A near the Airport
4% bollworm eggs
2% bollworm larvae
9% bollworm damage
Cry1Ac + Cry2Ab + Vip3A near the Wharton County fairgrounds
4% bollworm eggs
2% bollworm larvae
10% bollworm damage
Cry1Ac + Cry2Ab near the Wharton County fairgrounds
10% bollworm eggs
1% bollworm larvae
7% bollworm damage
Cry1Ac + Cry2Ab + Vip3A near Egypt
5% bollworm eggs
0% bollworm larvae
0% bollworm damage
Cry1Ac + Cry2Ab + Vip3A near Elm Grove
11% bollworm eggs
0% bollworm larvae
0% bollworm damage
Jackson County
Cry1Ac + Cry2Ab near El Toro
12% bollworm eggs
6% bollworm larvae
17% bollworm damage
Cry1Ac + Cry2Ab + Vip3A near La Salle
10% bollworm eggs
4% bollworm larvae
12% bollworm damage
Cry1Ac + Cry2Ab + Vip3A near Vanderbilt
4% bollworm eggs
2% bollworm larvae
10% bollworm damage
Matagorda County
Cry1Ac + Cry2Ab + Vip3A near Tidehaven
6% bollworm eggs
0% bollworm larvae
3% bollworm damage
Cry1Ac + Cry2Ab near Tidehaven
2% bollworm eggs
1% bollworm larvae
5% bollworm damage
Bollworms, Helicoverpa zea, are caterpillars that feed on multiple crops and vegetables. In cotton they feed on squares and bolls, causing fruit loss. These past few years we have had high numbers of this insect in our Bt cotton as well. All the larvae we've found this year have been very small, until this week I found one 1/2" larvae in a field near the Crescent area in Wharton.
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H. zea caterpillar in cotton square Kate Harrell |
To scout for cotton bollworms I use the terminal and square inspection method, as well as making some full plant checks, as they can lay eggs anywhere on the plant. I make about four stops in a field, more if the field is larger than 100 acres. At each stop, I look at 25 plant terminals, checking the upper third of the plant for caterpillars and eggs. I also pull 25 half grown or larger green squares to bolls and look for bollworm damage. When documenting egg lay, if I find more than one on a leaf, I only count it as one. The economic threshold for bollworms is 6% damaged bolls with live caterpillars present. In areas like ours on the upper gulf coast with documented Bt failures, the threshold for eggs on single and dual gene cotton is 20% (20 plants out of 100 with at least one egg). If you're finding bollworms in cotton or in corn, especially in viptera fields, please give me a call.
The current A&M recommendation is to use pyrethroids with caution. In areas needing residual control Prevathon at 18-20 fl oz or Besiege at 9-10 fl oz works well. If you don't need residual control you can get by with Prevathon at 14 fl oz or Besiege at 7-8 fl oz.
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Cotton Insect Guide
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This week I caught brown and green stink bugs in a field near the Crescent area of Wharton county with 6% damaged fruit, near the airport with 3% damaged fruit with no live stink bugs found, a field near Egypt with 3% damage and no live stink bugs, and a field near Elm Grove with 8% damage and live green stink bugs found. It is still buggy out there, and as our grain finishes out, more of them will move into cotton. To scout for stink bugs pull 10 to 20 bolls about an inch in diameter from four places in the field. Check the inside of the bolls for warts, lesions, and stained lint. Texas economic threshold for stink bugs is 20% or more of the bolls with internal damage and stink bugs present. Some of the brown stink bug populations in our area have also been shown to have some resistance to pyrethroids.
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Green Stink Bug adult Kate Harrell |
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Carpal Wall Warts from Stink Bug feeding damage Kate Harrell |
Below I have included information for stink bug thresholds from a South Carolina guide with good images of what damage looks like in bolls. Our cotton does not bloom as long as theirs, so the week of bloom threshold information will not line up exactly the same for our fields.
I hope everyone had a happy 4th of July and has a good weekend. If you're not sure what kind of insect or issue you have, feel free to drop by the Wharton county office or give us a call.
Sincerely,
Kate Harrell