Dual Magnum Label for Georgia Broccoli, Cabbage, Cauliflower, Collards, Onion, Bell Pepper, Beans, Cantaloupe, Watermelon, Carrot, Sweet Potato, and Tomato (Culpepper)

Over the past several years, I have worked with Syngenta to increase Dual Magnum herbicide options for vegetable growers as well as to improve our previously used labels; new labels are now available. A limited amount of this information will be available through the 2015 UGA Pest Control Handbook but a label must be in hand at time of application and the label will provide much more prescriptive information. 

Important Points:

1.  Growers must have a label in hand for these uses.  These labels are written by myself and Syngenta so if there is any confusion let me know.

2.  Agents MUST NOT give growers any indemnified label; agents should obtain their own label for knowledge.  The process of Growers obtaining labels is actually the method being used to indemnify the use of Dual Magnum in these crops.  If an agent was to provide a grower the label, it may make the agent or even UGA liable if issues were to occur. 

3.  Growers should evaluate these programs on limited acres until gaining experience.  Keep in mind these labels are developed from 10 to 15 studies conducted primarily by my research in Georgia; most other pesticide labels are developed from over 200 replicated trials conducted by dozens of scientists across the country.  

4.  Support Syngenta and use Dual Magnum; no generic company has shown any desire to support such challenging label development!!!!!!!!!!!!

Obtaining the label:

1.  Go to www.farmassist.com

2.  Select products along top bar.

3.  Select indemnified labels (4^th one down).

4.  Login (first time users create login and password).

5.  For state, select Georgia and for product, select Dual Magnum in this scenario (play around and see our other labels) and then submit.

6.  Select the Dual Magnum label and crop of interest and submit.

8.  Accept waiver; this is the process making the label an indemnified label.

9.  Print label and have present during application.

Deep Turning Reduces Annual Ryegrass Populations (Culpepper and Webster)

Georgia wheat production is in jeopardy due to herbicide resistant ryegrass.  Ryegrass resistant to all currently labeled postemergence controlling herbicides has been documented and is becoming very common.  Heavy ryegrass infestations, if uncontrolled by poor management or herbicide resistance, can eliminate production. 

Ryegrass has proven that it is capable of rapidly developing resistance to any and all herbicides used for management; even more so than Palmer amaranth.  A systems approach to management is the only sustainable option and may include rotating herbicide chemistries, rotating crops, and maybe even implementing deep tillage in the more severely infested fields.

Current research is being conducted to determine the potential benefits for deep turning to reduce annual ryegrass emergence.  In our first experiment, we planted ryegrass at 0.5 inch deep and followed with no tillage (our control) or deep tillage. 

Our objectives were to determine the following:

1) Could deep turning effectively invert seed on the soil surface?

2) Could inverted seed placed 10-12 inches deep in the soil profile germinate?

Results showed a reduction in ryegrass emergence by over 99% with deep turning (figure/picture below).  Although this experiment does not address ryegrass seed spread throughout the soil profile as is the case in grower fields, it does suggest ryegrass emergence is greatly reduced when it is placed deep in the soil profile.  The next step is to better understand how long the seed will live when buried in our soils under our environmental conditions.  

Rarely will any cultural or mechanical practice effectively control ryegrass by itself.  Thus, an herbicide program will usually be needed.  See the wheat production guide or pest control handbook for herbicidal options.

Zidua Use in Wheat (Culpepper)

Zidua (pyroxasulfone), can be applied as a delayed preemergence or early postemergence application in wheat that is planted between 0.5 and 1.25 inch deep.  Zidua CANNOT BE APPLIED AS A TRUE PREEMERGENCE!

Delayed preemergence applications can occur when 80% of the germinated wheat seeds have a shoot at least ½ inch long up until spiking; applications of 0.7 to 1.0 oz/A (coarse soils) are appropriate for most Georgia fields while the rate can be increased to 1.25 oz/A on medium to fine soils.  Do not irrigate fields treated with a delayed preemergence application until wheat spiking and DO NOT apply delayed preemergence applications to broadcast-seeded wheat.

Early postemergence Zidua applications can be applied to wheat at spiking up to the fourth-tiller growth stage at a rate of 1.0 to 2.0 oz/A. 

Sequential applications may also be applied as long as the total use rate does not exceed 2.5 oz/A.

Ryegrass Control: If Zidua is activated prior to ryegrass emergence, excellent control is expected; however, if ryegrass is up at time of Zidua application then control of the emerged plants will likely be poor.  The label allows for mixtures with Axial which should control small emerged ryegrass plants that are not resistant to Axial.  Suppression of some broadleaf weeds will occur but control will not be good enough to replace broadleaf herbicide applications, especially for wild radish.

Crop Injury: Greatest potential for injury occurs when open/cracked seed furrow allows herbicides to directly contact the seed, when seed are planted to shallow, or when seed are planted in a deep furrow that allows herbicide concentration after a rain/irrigation event during wheat germination.  

Late-Season Peanut Questions (Prostko)

A couple of quick answers to some peanut questions that I have been getting over the past week or so:

1) Can I tank-mix Mn fertilizers with herbicides and/or fungicides?

Recent research from NC State University indicated that manganese did not affect the efficacy of Select, Poast, Cadre, Pursuit, 2,4-DB, Abound, Bravo, Headline, or Folicur.  Common ragweed control with Cobra was reduced 6% by dry Mn sulfate but not liquid Mn.   (Peanut Science 2012 39:1-8)

2) What weeds can be controlled using non-selective applicators (NSA) such as the Weed-Wiper or ropewick?

UGA has data to suggest that Palmer amaranth, Florida beggarweed, and sicklepod can be controlled late-season with NSA using a 50% solution of paraquat.  Please refer to page 452 of the 2014 UGA Pest Control Handbook for additional information.  Remember that the only benefits of this type of application would be improved harvest-efficiency and fungicide spray deposition.  It is way too late to recover any competition related yield losses.

3) Is there anything that can be done to help control Benghal dayflower/tropical spiderwort at this time of the year (i.e. 100+ day old peanuts)?

a) No!!!! Revenge sprays are not practical!!  Dayflower/spiderwort plants at this time of the year are too big to control with herbicides.  Additionally, late-season applications of herbicides such as Strongarm could have a significant impact on 2015 crop rotations.  Although Aim can be used as an harvest-aid, previous research has shown that single applications to 8-10" tall spiderwort plants provided < 45% control.