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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Peanut Tips - Week of May 23 (Prostko)

A few comments based upon some frequent questions that I have received this week:

1) Generally, there should be no major problems mixing Orthene (acephate) with paraquat cracking treatments (Peanut Science 2014 41:58-64).

2) UPI is in a sold out position for Storm 4SL herbicide.  However, Storm is in UPI's production schedule for next year.  No worries though since growers can make their own Storm if need be.  1.5 pt/A of Storm would be equivalent to 1 pt/A of Ultra Blazer 2SL +  1 pt/A of Basagran 4SL.  FYI, when making your own Storm cocktail for mixing with paraquat, I prefer 1 pt/A of Ultra Blazer + 0.5 pt/A of Basagran.  0.5 pt/A of Basagran still helps "safen" the peanuts but this new ratio will be slightly more active on the weeds.  

3) Helena has been actively promoting a product called ENC (Ele-Max Nutrient Concentrate) to be used in combination with paraquat cracking sprays.  According to Helena, the use of ENC will help the peanuts recover faster from paraquat injury.  As far as I can tell, ENC is a fertilizer solution (11-8-5 + various micros).  We are currently evaluating this product and its potential benefits.  Preliminary results from 1 trial in Attapulgus this year would suggest that the use of ENC resulted in less peanut injury (leaf burn) at 3 DAT (Figure 1) but no differences were detected at 7 DAT (Figure 2).  Way too early for a yea or nay recommendation at this point!!!  More to follow as additional data is collected.  

Figure 1.  Influence of ENC on peanut leaf burn - 3 DAT - 2016.

Figure 2.   Influence of ENC on peanut leaf burn - 7 DAT - 2016.

4) Guess what?  When it rains on peanuts that were treated with Valor, especially at cracking, you get crop injury.  It happens all the time, regardless if they were irrigated immediately after application or not.  Unless something funky has happened (i.e. sprayer problems, excessive rates, misapplication, etc.), research results and on-farm experiences since 2001 would suggest that is very likely that the peanut plants will recover from Valor injury with no yield loss.  For more info and injury pictures, refer to my June 3, 2013 blog on this very same issue.

Liquid Flumioxazin Mixing Problems (Prostko)

Panther 4SC (NuFarm) is a new liquid formulation of the active ingredient flumioxazin (i.e. Valor). This week, I have heard a few complaints about some tank-mixes with this new formulation. Growers who use this liquid formulation must follow the mixing order described below in order to minimize potential tank-mix problems:

Check out the following YouTube video for some cool visuals about Panther 4SC.  FYI, I have not sprayed a single drop of Panther 4SC so I have no experience or data at this point with this new formulation.

https://www.youtube.com/watch?v=PvpsOI7C50M

Metribuzin on Soybeans (Prostko)

As many of you know, I have been trying my very best to prevent the overuse of Valor and Reflex in soybeans, especially for growers who also plant cotton and peanuts.  Growers who want to protect Valor and Reflex (PPO's) have many other PRE options including Dual, Warrant, and metribuzin.  For you Roundup babies out there, let me remind you of a few things about metribuzin.

1) Metribuzin used to be sold under the trade names of Sencor (Bayer) or Lexone (DuPont).  Many moons ago, about 20% of the US soybean crop was treated with metribuzin.  

2) Current trade names for metribuzin include the following: Tricor, Metribuzin, Dimetric.

3) Metribuzin is also a component of many soybean pre-mixes including the following: Authority MTZ (metribuzin + Spartan), Boundary (metribuzin + Dual Magnum), Canopy or Canopy Blend (metribuzin + Classic) ), Intimidator (metribuzin + Reflex + Dual Magnum), and Trivence (metribuzin + Valor + Classic). 

4) When using metribuzin in soybeans, soil type, OM and pH are very important.  Metribuzin should not be used on coarse soils (i.e. sandy loam or loamy sand) with less than 1% OM and/or in soils with a pH greater than 7.5.  Refer to the individual product labels for more specific information about use rates, soil types, and organic matter restrictions.

5) Metribuzin should not be used on sensitive soybean varieties.  Check out page 268 of the 2016 UGA Pest Control Handbook for a partial list of soybean varieties that have been screened for tolerance.  Also, check out the following publication from the University of Arkansas ( http://mssoy.org/wp-content/uploads/2014/12/2014-SOYBEAN-VARIETY-METRIBUZIN-SCREENING-UA1.pdf).  

6) Metribuzin is in the same herbicide family as atrazine (triazine). Metribuzin is a PS II inhibitor (WSSA Group 5).

7) Metribuzin injury symptoms on soybeans are presented in Figures 3 and 4.  

Figure 3.  Metribuzin injury on soybeans.

Figure 4.  Metribuzin injury on soybeans.

Prowl vs. Sonalan in Peanuts (Prostko)

Recent price increases in Sonalan 3EC (ethalfluralin) have many growers taking a closer look at the cheaper priced pendimethalin formulations (Generic Prowl 3.3EC and Prowl H2O 3.8ASC) for use in peanuts.  With the exception of use in reduced tillage systems (i.e. Prowl is preferred there), there have been no consistent differences in peanut tolerance and weed efficacy between Sonalan and Prowl in peanut (Table 1).  It has always been my position that I have no preference between these two herbicides and that every peanut acre in Georgia should be treated with one of them.  If a grower is trying to save a few bucks on input costs, there is no reason not to use a cheaper formulation.

A couple of other comments about this issue:

1) The Weed Science Group at UGA has not been able to detect any major differences in the performance between Prowl 3.3EC and Prowl H20 3.8ASC.
2) 2016 estimated costs for 1 qt/A are as follows:  Sonalan 3EC = $10.50; Generic Prowl 3.3EC = $6.75; and Prowl H2O 3.8ASC = $8.75.
3) The lb ai/A for each formulation are slightly different at the 1 qt/A typical use rate as follows:  Sonalan 3EC = 0.75 lb ai/A; Generic Prowl 3.3EC = 0.83 lb ai/A; and Prowl H2O 3.8ASC = 0.95 lb ai/A.  This might need to be considered when figuring the true cost differences per acre.  

Indemnified Label Allows Dual Magnum Overtop of Summer Squash – Yellow and Zucchini (Culpepper)

Our new label allowing Dual Magnum over-the-top of emerged seeded and transplant squash grown on bare-ground or in a mulch system has been approved for use in Georgia.  The label should be self-explanatory….if not let me know as I was one of the authors.  

Getting Label: See steps below on obtaining the label (this information has been provided several times).

Grower Must Obtain His/her Label: For years we have stressed the importance of growers having a copy of our state local need (SLN) indemnified labels when making applications. This is getting more serious as the Department of Agriculture has started asking to see these labels doing routine visits; this is simply a response to the sheer volume of state local need labels we now have for Georgia growers.  To drive the point home here is an e-mail from GDA a few weeks ago “Dr. Culpepper, If you talk to any grower groups regarding any SLN approvals, please remind them that they must keep or present the SLN label for our inspectors during an audit or it is a label violation. Our inspectors find many individuals that cannot produce an SLN label during farm inspections.”

Thanks,

Eric Olsen

GDA”

OBTAINING LABELS FOR DUAL MAGNUM OR REFLEX:

Consider helping your growers by asking them to come in and visit with you to get their label. This is a great opportunity for young/new agents to obtain face time with our clientele!!

Agents MUST NOT give growers any indemnified label or make any verbal recommendations until the grower has the label.  Agents can help growers through the process but must make sure the grower clicks the “I ACCEPT” liability waver when obtaining the label.

Obtaining the label for First Time (first time takes a couple minutes, thereafter very simple):

1.  Go to www.farmassist.com

2.  Register the grower (or if you want a label register yourself); “register” is located on the 2nd tool bar in top middle of page.  After filling in information; click I accept at bottom.

3.  The next page that pops up asks about you; you do not have to fill this out if you do not want.

4.  Select products along top bar.

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

6.  For state, select Georgia and for product, select Dual Magnum or Reflex (play around and see our other labels) and then submit.

7.  Select the Dual Magnum or Reflex crop of interest and submit.

8.  Accept waiver; this is the process making the label an indemnified label.  GROWER MUST CLICK THE  I ACCEPT KEY TO GET THEIR LABEL!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

9.  Print label and have present during application.

Sweet Potatoes and Cadre (Culpepper and Prostko)

Over the last several years, many county agents have asked about carryover concerns of Cadre applied in a peanut crop to sweet potato the following season.  The Cadre label restricts planting potatoes to 40 months after a Cadre application but the label does not specifically mention sweet potato.  Many have wondered is it really this serious?

According to the 2014 edition of the WSSA's Herbicide Handbook (page 256), the half-life of Cadre or the time in which about half of the Cadre would be gone is approximately 120 days.  In theory then, a June application of Cadre at 4 oz/A in peanut should be down to a rate somewhere between ½-1 oz/A approximately 8-12 months later when one would plant sweet potato.  

During 2015, a study was conducted where we applied ½ and 1 oz/A of Cadre prior to transplanting sweet potato.  Cadre at ½ oz/A caused 55% visual injury (stunting and discoloration) and reduced U.S. Number 1 fruit yield by 59%.  For Cadre at 1 oz/A, sweet potato injury reached 77% and reduced U.S. Number 1 fruit by 96%.  Simply, applications of Cadre in peanut should be avoided if you plan to rotate to sweet potato!!!!!.