Howdy,

  All the cotton I've looked at this week is past cutout (5 nodes above white flower) and a good number of fields have open bolls. I've been seeing the bollworm (H. zea, corn ear worm, etc.) egg lay decreasing, and most of the larvae are cycling out. Last week I spent a good deal of time collecting bollworms out of double traited and one vip traited field. Those bollworms have been sent to the lab in College Station for Bt resistance testing.

Large Cotton Bollworm in Cry 1Ab + Cry 2Ac Cotton

Photo: Kate Harrell

Treatment options for Cotton Bollworm in Cotton

Managing Cotton Insects - Page 31

  In places still susceptible to bollworms, it's important to be checking for them even if you have Bt cotton. There is no threshold set for egg lay (since they have to feed for Bt to effect them and many other insects consume eggs), but our adapted threshold for caterpillars after last year is 6% damaged bolls or squares with live caterpillars present. When cotton reaches cutout (5 NAWF), it has 350 heat units remaining before the bollworms can no longer cause yield loss.

Stink Bug
Photo: Kate Harrell

Carpal Warts in Cotton
Photo: Kate Harrell

  In the places that are still susceptible to stink bugs, the threshold for stink bugs is 20% of bolls damaged with stink bugs present. Once cotton has reached 450 heat units past cutout, treatment for stink bugs may no longer be necessary, as the bolls they can still feed on will not mature in time to contribute to the overall yield. Fields that experienced drought stress this year may have a longer time frame for yield loss to occur, and stink bugs may still need to be a consideration until 450 heat units past 3 or 4 NAWF.

Hope everyone has a great weekend and safe grain harvest!

Sincerely,

Kate

For more information check out:

Texas Row Crop Newsletter

Managing Cotton Insects in Texas

 Wharton - AgriLife Extension to host a Cotton Turn Row Meeting – July 17th

 By Corrie Bowen

County Extension Agent

Wharton County

Texas A&M AgriLife Extension, Wharton and Matagorda County Offices will host a Cotton Turn Row Meeting on Tuesday, July 17, 2018 in Wharton.  Registration will begin at the Directors Room at the Wharton County Fairgrounds at 8:30 a.m.  Program to begin at 9:00 a.m. with an overview of the 2018  Cotton Crop.  We’ll then proceed to our Replicated Agronomic Cotton Evaluation (RACE) trial where we’ll hear from Dr. Gaylon Morgan, Extension Cotton Specialist with discussion on cotton varieties and late season issues.  Dr. Scott Nolte, Extension Weed Specialist will follow with discussion on minimizing off-target herbicide movement.  By 11 a.m. we’ll return to the Directors Room where Greg Baker with discuss Worker Protection Standard requirements for pesticide workers and handlers. 

The WPS is a federal regulation originally enacted in 1992 designed to protect agricultural workers (people involved in the production of agricultural plants) and pesticide handlers (people mixing, loading, or applying pesticides or doing other tasks involving direct contact with pesticides). You probably need to comply with the WPS if you are a:  Manager or owner of a farm, forest, nursery, or greenhouse; or Labor contractor for a farm, forest, nursery, or greenhouse; or  Custom (for hire) pesticide applicator or independent crop consultant hired by a farm, forest, nursery, or greenhouse operator.  The EPA made significant revisions to the WPS provisions that became effective January 2, 2018.  Most WPS provisions are protections that you, as an employer, must provide for your own employees and, in some instances, to yourself. The WPS covers two types of employers, which it defines according to the type of work their employees do.  Bring your farm employees (agricultural workers and/or pesticide handlers) to the July 17th Turn-Row meeting, as the WPS training at 11 a.m. will satisfy the annual WPS training.  The WPS training video will be provided in English.  Please contact the Wharton County Extension office prior to July 17th at 979-532-3310 if you have employees attending who will need to view the Spanish version of the WPS training.

Program will conclude at noon.  3 CEUs will be offered for TDA pesticide license holders and 3 CCA credits have been applied for.  Please call the Extension Office by  5:00 p.m. on July 16 just to let us know that you’ll be attending.  A flyer  for the July 17th turn-row meeting is available at https://wharton.agrilife.org.

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.

Check your Bt for Bollworms

Howdy everyone,

Bollworm Egg
Photo: Kate Harrell

  I've looked at cotton past cutout (5 nodes above white flower) in all three of my counties this week, this season has been flying by. I've been seeing the bollworm (H. zea, corn ear worm, etc.) egg lay and some larvae. The most larvae we found this week was near Elm Grove, with 5 small caterpillars on 100 plants. I spent a good bit of time in a field trial location this week, and was finding a few live caterpillars in everything but the Viptera traited cotton.

  Most of our Bt technology is not working as well as it has been in the past, as we saw last year. It still has some activity on worms, but when we tested last year in our area, the bollworms have resistance to all but the new Viptera trait. The chart below shows the current and past technologies, and the overlap between them. This overlap has helped select for bollworms that are no longer effectively controlled by the technology.

  Even if you have Bt cotton, it's important to be checking for bollworms. There is no threshold set for egg lay (since they have to feed for Bt to effect them and many other insects consume eggs), but our adapted threshold for caterpillars after last year is 6% damaged bolls or squares with live caterpillars present. When cotton reaches cutout (5 NAWF), it has 350 heat units remaining before the bollworms can no longer cause yield loss.

Large Cotton Bollworm in Cry 1Ab + Cry 2Ac Cotton
Photo: Kate Harrell

Treatment options for Cotton Bollworm in Cotton
Managing Cotton Insects - Page 31

  I am using the whole plant inspection method when scouting, and have been looking at 50 to 100 plants in 4 or 5 different places in the field, depending on the field size. I look over the entire plant and count the number of undamaged bolls or squares, and the number of damaged ones. I am also pulling 10-15 bolls at each spot I check to look for stink bug damage. Damage can entail carpal warts on the inside of the bolls, or brown and damaged lint and seed in the boll. The threshold for stink bugs is 20% of bolls damaged with stink bugs present. Once cotton has reached 450 heat units past cutout, treatment for stink bugs may no longer be necessary, as the bolls they can still feed on will not mature in time to contribute to the overall yield. Fields that experienced drought stress this year may have a longer time frame for yield loss to occur, and stink bugs may still need to be a consideration until 450 heatu units past 3 or 4 NAWF.

Carpal warts from stink bug feeding
Photo: Kate Harrell

  I'm still seeing some aphids in cotton as well. Treatment for aphids in cotton is rarely warranted at this growth stage. The threshold is at 40-70 aphids per leaf until bolls begin to crack. Once we have open bolls, the threshold drops to 10 per leaf, as the honeydew can cause mold to grow on lint and cause problems with harvest. If you know you have aphids and need to spray for either bollworms or stink bugs, try to either choose a more selective chemical for treating your pest to avoid knocking back the beneficial populations and flaring the aphids, or look for an insecticide with aphid activity as well.

Minute Pirate Bug eating an Aphid
Photo: Kate Harrell

 I hope everyone has a safe grain harvest!

Sincerely,

Kate Harrell

For more information check out:

Texas Row Crop Newsletter

Managing Cotton Insects in Texas

Sugarcane Aphid Scouting Card