Zest™ Approved for Use in Inzen™ Grain Sorghum (Prostko)

I just received word that Zest™ 75WDG (nicosulfuron) has received Georgia approval for use on Inzen™ herbicide-tolerant grain sorghum varieties.  Grain sorghum growers who use this technology will now be able to get better POST control of Texas panicum and other grasses.  I have discussed Zest/Inzen in a previous UGA Weed Science Blog (February 15, 2016) and in our December agent training meetings. Nicosulfuron is the same active ingredient in Accent, which is registered for use on field corn.

A couple of reminders:

1) Zest can only be used on Inzen herbicide-tolerant grain sorghum varieties. The use of Zest on conventional sorghum varieties will result in crop death! Inzen grain sorghum varieties are not GMO's.

2) The current formulation of Zest is a WDG.  I have been testing a liquid formulation so rates would be different in any slides you have previously seen from me.

3) UGA has limited variety performance data (i.e. none).  As far as I know, the only company with Inzen varieties is Advanta/Alta (http://altaseeds.advantaus.com).  Pioneer will likely have some varieties in 2018 or 2019?  Thus, I would suggest Georgia sorghum growers proceed with caution until an adapted variety is identified.  I have not been overly impressed with the varieties that I have been testing up until now.

4) I would still recommend the use of Concep treated seed + a PRE application of Dual or Warrant in this system.  Atrazine should be tank-mixed with Zest to improve the control of broadleaf weeds.

5) A copy of the complete Zest label can be accessed from the following location:
http://www.cdms.net/ldat/ldDEH000.pdf

Dicamba Labels Approved (Prostko)

Yesterday, the EPA approved the first labels of dicamba for use on on dicamba-tolerant cotton and soybeans. A few interesting highlights from the labels include the following:

1) Xtendimax™ with VaporGrip™ Technology can ONLY be tank-mixed with products that have been tested and found not to adversely affect off-site movement potential.  A list of those products can be found at www.xtendimaxapplicationrequirements.com (This site was not yet available for viewing as of 9:24 am today).

2) Only 1 nozzle type is permitted (TTI11004 with 63 PSI max)

3) Must be applied in a minimum of 10 GPA

4) Maximum ground speed is 15 MPH

5) Maximum boom height of 24" above target pest or crop canopy

6) Can only be applied when winds are between 3 MPH and 15 MPH (3 MPH to 10 MPH is optimum).

7) Must maintain a 110 to 220 foot downwind buffer, depending upon rate, between the last treated row and the closest downwind field edge.

8) A copy of the cotton label can be viewed at the following location:

https://www.regulations.gov/document?D=EPA-HQ-OPP-2016-0187-0958

If you are not familiar with VaporGrip™ technology, refer to the following YouTube video:

https://www.youtube.com/watch?v=IWW4scEgpuU

More specific and up-to-date information will be presented at the UGA Weed Science Agent Update on December 7.

Using Pesticides Wisely - 2017 Classroom Trainings (Culpepper)

We are currently planning a final round of trainings for our Using Pesticides Wisely training during February/March of 2017 and would request your input on potential locations.  Our goal continues to be making it as easy as possible for attendance.   To date, we have conducted the training 26 times in Georgia as noted below.  Please e-mail Culpepper at stanley@uga.edu to give us feedback on where we have growers that we have missed and your thoughts on potential locations by November 1, 2016.  A few other thoughts about this training:

*Remember if auxin technologies do get labeled, which is currently unknown, licensed applicators responsible for in-crop applications of dicamba or 2,4-D, in respective technologies, will be required to take this training.

*Our estimates suggest we have trained at least 85% of the growers that would want to use these technologies.

*The small number of people left to train should easily fit in county offices, so our locations will be at Agent facilities if agents are supportive.

*Anticipating 2 or 3 final locations for South Georgia and 2 locations for North GA?

Off-Label Dicamba Use (Prostko)

     In case you have not heard, there have been numerous problems in certain states, such as Missouri and Arkansas, with off-label applications of dicamba on dicamba-resistant crops.  In Arkansas, things have gotten so out of hand that the Arkansas State Plant Board is proposing numerous restrictions on the use of dicamba in their state.  Some of these potential restrictions include the following:

1) Banning the use of dimethylamine (DMA) salt and acid formulations (i.e. Banvel), except on pastures/rangeland but only if all susceptible crops are at least 1 mile away in all directions.

2) Prohibiting the application of dicamba diglycolamine (DGA) salt and sodium salt formulations (i.e. Clarity) from April 15 through September 15 (except on pastures/rangeland with the 1 mile susceptible crop buffer).

3) When BASF's Engenia formulation (dicamba-BAPMA) is used, a 1/4 mile downward buffer zone and 100' buffer zone in all other directions will be required.  Engenia is less volatile than Banvel or Clarity.

4) New certification training will be required for both the Enlist (2,4-D) and Xtend (dicamba) technologies.  As you already know, we (UGA Extension) have been doing this type of training for 2 years.  

     These restrictions are not final with a 30 day comment period and public hearing scheduled for November 21.  Ultimately, the Governor and state legislature in Arkansas will have the final say.

     As far as I know, Georgia growers have done a good job of not abusing dicamba this year and there has been no talk of restrictions such as those listed above in our state. However, what's going on in Arkansas should serve as a reminder to any Georgia grower or chemical dealer of the potential consequences of off-label uses or violations.  Since Georgia is a large producer of potentially sensitive speciality crops, it will be important for all of us involved in this situation to do the right things and use common sense!!!

Weed Update - August 19, 2016 (Prostko)

It has been a while since my last blog.  In the last 60 days, I was out of commission for at least 27 days for various reasons (vacation time, 3 professional meetings, and 2 college moves).   However, the telephone calls kept rolling in!  Here are a few things to consider based upon recent calls:

1) Glyphosate will not adequately control sicklepod plants that have emerged thru the top of a soybean canopy.  However, glyphosate might have some effect on seed rain depending upon the sicklepod stage of growth at application and how much of the plant actually gets treated (Figure 1).  However, I would not expect as much seed reduction as depicted in this graph if only a few inches of the sicklepod plant actually gets treated with glyphosate. 

Figure 1.  Late-season response of sicklepod to glyphosate @ 0.75 ai ae/A as influenced by application timing.

2) Growers who have planted ultra-late soybeans need to be more conscious of herbicide crop rotation restrictions.  For example, Reflex, Prefix, or Warrant Ultra all have a field corn rotation restriction of 10 months (yes, this is real!!).  Thus, these herbicides should be avoided if field corn will be planted early next spring.  POST soybean herbicides with minimal crop rotation restrictions include Liberty, Cobra, or Ultra Blazer.  

3) At this time of year, there are NO miracle cures or magical silver bullets for escaped morninglory, Texas panicum, or sicklepod in any crop.  Growers will need to rely on harvest aids or non-selective applicators when appropriate and/or labeled.  What's the best strategy for controlling a 12-24" weed?  Treating it when its 3" tall!!!!!!!!!!!!!!  Sometimes a difficult but necessary pill to swallow.

4) Growers need to stay vigilant in their post-harvest (corn) weed control efforts to minimize weed seed-rain back into production fields.  It would only take a few escaped, seed-producing plants to mess up multiple years of good weed control.  Please refer to pages 74 and 87 of the 2016 UGA Pest Control Handbook for more information about post-harvest weed control strategies.

5) As a reminder, I would be more than happy to spend some time in any county at this time of year at your request!  

Weed Science Update - Week of July 4, 2016

1) This is what an IPhone 6 + LifeProof case looks like after mowing with a Massey Ferguson 2615 (50 HP) + 6' rotary mower.  I have a new phone now so please feel free to call me as usual.  

2) Earlier this week, I had some questions about peanut fungicide tank-mixes with Cobra and Strongarm.  Here is what I know based upon some older data (not much though):

a) Cobra + Fungicides:  Results from a field trial conducted in 2005 suggested no problems with Cobra + Bravo or Folicur.  When Abound was tank-mixed with Cobra, Florida beggarweed control was reduced by 12%. When Headline was tank-mixed with Cobra, annual morningglory control was reduced by 8%. All treatments also included COC @ 1% v/v. Peanut injury was not increased with Cobra + fungicide tank-mixtures. All treatments were applied to Georgia Green at 28 DAP.   

b) Strongarm + Fungicides:  From another field trial conducted in 2005, annual morningglory control was not reduced when Strongarm was tank-mixed with Bravo WS, Abound, Folicur, and Headline.  Florida beggarweed control with POST applications of Strongarm was poor in general (<70%) and control was further reduced by 15% when tank-mixed with Headline.  NIS @ 0.25% v/v was included with all treatments.  Peanut injury was not increased with Strongarm + fungicide tank-mixtures.  All treatments were applied to Georgia Green at 23 DAP.

3) Someone asked me about the tolerance of soybeans to dicamba drift.  As with most drift situations, it all depends upon rate and stage of growth.  Generally, soybeans are less tolerant of dicamba drift at reproductive stages of growth.  

Peanut Tank-Mix Time (Prostko)

Now is the time of year that most of us will get numerous questions about the various tank-mixes that peanut growers would like to try.  Here are a few reminders:

1) With over 90,000 potential peanut tank-mixtures, it is impossible for UGA or anyone else to have all the answers.  If a  grower puts more than 2 chemicals in a spray tank, it is very likely that that specific mixture will not have been adequately tested.

2) Just because a specific tank-mixture may not have caused peanut injury on one day, it does not mean it will not cause injury at another time.  Peanut response to tank-mixtures is a function of many factors including temperature, humidity, leaf wetness, and overall plant health.

2) The following is a good publication to keep handy at this time:  Tank-Mixing Chemicals Applied to Peanut Crops: Are the Chemicals Compatible?.  This publication can be accessed from the web at the following location:

http://www.peanut.ncsu.edu/pdffiles/004993/tank_mixing_chemicals_applied_to_peanut_crops.pdf

3) 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)

4) Here a few slides of some tank-mixtures that I have tried or seen in the field.

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