Thursday, May 12, 2011

Palmer Amaranth in Soybeans

Wesley Everman, Weed Science Extension Specialist
Alan York, Professor Emeritus
Crop Science Department, North Carolina State University

Glyphosate-resistant Palmer amaranth is wide-spread across the Coastal Plain and is showing up alarmingly fast in the Piedmont. Not all Palmer amaranth in North Carolina is glyphosate-resistant. However, growers are encouraged to assume that all Palmer amaranth is resistant to glyphosate and to react accordingly.

Growers who currently do not have Palmer amaranth are encouraged to prevent it from becoming established. Learn to recognize the weed and remove any escapes before a seed head is produced. A single female Palmer amaranth can produce a half million seed. If the seed were uniformly distributed, that is equivalent to more than 10 seed per square foot over an entire acre. Don't ignore escaped weeds; devastating populations can build up quickly. Clean equipment as well as possible when moving from infested to non-infested fields.

Rotate crops and chemistry as much as possible. Include corn in the rotation where practical; atrazine-based programs are very effective on Palmer amaranth. Be careful to not negate the benefits of rotation by allowing a crop of seed to be produced after corn harvest. In the fall, Palmer amaranth can go from seed to seed in about 40 days.

Palmer Amaranth Control in Roundup Ready Soybeans

Programs for Palmer amaranth control in Roundup Ready soybeans are detailed on the back of this sheet. Three key points should be kept in mind. First, a residual herbicide applied preplant or preemergence should always be included in a program. Additional residual control from a postemergence application is also beneficial. All of the postemergence options listed on the back, except Harmony SG, have residual activity on Palmer amaranth. The second key point is timing of application. Palmer amaranth should be treated postemergence before it exceeds 4 inches tall. If the weed is resistant to glyphosate, the material mixed with glyphosate must do all the work; hence, the treatment should be applied to weeds of the size appropriate for the tank-mix partner. Remember, this weed can grow an inch or more per day. Treating larger weeds not only results in less control, but it can also accelerate selection for resistance to PPO inhibitors (Authority, Blazer, Cobra, Envive, Flexstar, Prefix, Reflex, Valor, others), something we can ill afford. Third, fomesafen (the active ingredient in Flexstar and one of the ingredients in Prefix and Flexstar GT) behaves as a contact herbicide. That means good spray coverage is required. While lower spray volumes and air induction nozzles are fine with glyphosate alone, use of flat-fan nozzles and a spray volume of 15 gallons per acre or more will enhance Palmer amaranth control with Flexstar, Flexstar GT, and Prefix applied postemergence.

Palmer Amaranth Control in LibertyLink Soybeans

Management programs for Palmer amaranth in LibertyLink soybeans are basically the same as those for Roundup Ready soybeans (detailed on the back) with the obvious exception that Ignite 280 herbicide is used instead of glyphosate postemergence. Growers are encouraged to not abuse this herbicide. Ignite will likely be increasingly important for us in the future, hence we must avoid selection for resistance. Do not depend entirely on Ignite, do not exceed two applications per year, do not cut rates, and treat small weeds (treating large weeds is equivalent to cutting rates, which encourages resistance). A residual herbicide or herbicides applied preplant or preemergence is always recommended. Additional residual control can be obtained from Dual Magnum, Warrant, Flexstar, or Prefix mixed with Ignite. Timely application is critical for successful Palmer amaranth control with Ignite. For consistent control, Palmer amaranth must be 4 inches or less when treated. A supplemental label was recently issued for Ignite 280 that allows higher application rates on LibertyLink soybeans. The supplemental label allows two in-crop applications, with the first application being 22 to 36 fl oz/acre, and the second application being 22 to 29 fl oz. It is suggested that no less than 29 fl oz be applied. Hit them hard, hit them small. Ignite is a contact herbicide, hence good coverage is critical. It should be applied in a spray volume of at least 15 gallons per acre using flat-fan nozzles. Air-induction nozzles generally will not provide adequate coverage for a contact herbicide.

Saturday, May 7, 2011

Carolina Pest News

In This Week’s Issue . . .

* Wheat Research Field Days Schedule for North Carolina

* Brief Update on Cotton Insects
* Cotton Insect Teletip Down
* Kudzu Bug is Confirmed in More North Carolina Counties

* Southern Pine Beetles
* Magicicada Exposure
* Crape Myrtle Aphids Not So Bad
* Flower Thrips Attack Knockout Roses

Caldwell Co. Pesticide Collection Day - May 19, 10am - 2pm

A pesticide disposal day will be held Thursday, May 19 from 10:00 am to 2:00 pm at the Caldwell Ag Center / Public Library. This will provide an opportunity for farmers, gardeners, and homeowners to dispose of any unwanted pesticides (insecticide, herbicide, fungicide, etc.) free of charge. The collection is only for labeled pesticides, other house hold hazardous waste will not be accepted. If containers are leaking or fragile, place them in a five gallon bucket with absorbent material such as cat litter or sawdust. Do not transport pesticides in the front of a truck or car. If you have containers larger than five gallons or if you have questions about this pesticide disposal day, please call the Caldwell Extension Center at 828-757-1290 or email

Tuesday, January 25, 2011

Mike Roberts - Weekly Ag Commodity Report

Many of you may remember Dr. Geoff Benson, NCSU Dairy Extension Economist. Mr. Mike Thomas Roberts has been hired to fill Geoff's vacant position. Mike comes to NCSU from Virginia were he published a weekly ag commodity report. To read Mike's weekly commodity report or to learn more about mike visit his NCSU page and link to the weekly report.

Thursday, January 20, 2011

Ag Forum - Feb. 3 at State Fairgrounds

Input costs, water resources and the effects of monetary policy on agriculture will be among the topics of discussion at the sixth annual Ag Development Forum Thursday, Feb. 3, at the State Fairgrounds.

Agriculture Commissioner Steve Troxler also will deliver his annual State of Agriculture address at the forum, which will take place from 9:30 a.m. to 12:30 p.m. in the Holshouser Building.

Keynote speaker will be Matthew Martin, an economist and senior vice president at the Federal Reserve Bank of Richmond's Charlotte branch. His remarks will focus on the economic outlook for agriculture and the effects of monetary policy on the industry.

This will be a great opportunity to come learn more about economic factors affecting farmers, Troxler said. This is going to be a critical year to stay informed because of ongoing economic concerns in North Carolina, the United States and even globally.

There also will be a panel discussion focusing on the cost of agricultural inputs, such as seed and fertilizer.

Other agenda items include the unveiling of a strategic plan for agricultural water resources in North Carolina.

Farmers, agribusiness professionals and others interested in agricultural policy and economics are invited to the forum. Admission is free, and lunch will be provided. Registration is requested by Jan. 28. To register, go to People with questions should contact Christina Waggett at (919) 707-3008.

The forum is sponsored by Altria and the N.C. Foundation for Soil and Water Conservation.

Have Crop Problems?

I just want to make growers aware we have funding from the North Carolina Small Grain Growers Association, Inc. for us to submit problem samples for diagnosis at the NCSU Plant Disease & Insect Clinic (30 total) and the NCDA&CS Agronomic Services Division Plant Tissue Laboratory (70 total). If you have small grain problems, I now have the ability to submit samples from Caldwell County "gratis", also known as FREE! As always, just give me a call 828 757 1290 or send and email (

Wednesday, January 12, 2011

Waynesville Bul sale results

The Waynesville bull test sale held on January 8, 2011 had the following averages; total sale $2182.60, Angus $2157.89, and Simmental $2300. A total of 23 bulls of the 24 offered were sold on that day. One bull (#81) listed in the catalog was scratched from the sale due to health problems. The high selling bull brought $5000, which tied the previous sale record set the first year of the Waynesville bull sale. Attendance at the beef conference was fairly low due to the snowstorm, however there were plenty of buyers at the sale. Thanks again to the sponsors of the beef conference and bull sale Southeast Livestock Exchange, Carolina Farm Credit, North Carolina Farm Bureau, and Sevier Farmers COOP.

Submitted by: Dr. Jim Turner,
NCSU Extension Western Beef Specialist