Valor Injury on Peanut Is likely (Prostko)

Rainfall events of May 20/21 will likely result in Valor injury on peanut.  Although I have addressed this issue in many previous blogs (June 3, 2013; May 20, 2014, May 26, 2017, May 6, 2019), here is another general summary of the Valor injury/yield data that I have collected over the past 21 years: 

1)      11 replicated field trials with reliable yield data

2)      11/11 trials, Valor 51WG @ 3 oz/A had no negative effect on peanut yield

3)      9/11 trials, no difference in yield between 3 oz/A and 6 oz/A (FYI, 6 oz/A is not labeled or recommended)

4)      2/11 trials, 6 oz/A caused yield losses when compared to 3 oz/A (6.9% to 8.8% yield loss).

Bottom line is that peanut fields suffering from injury, when Valor was applied at the labeled rate (3 oz/A) and timing (no later than 2 DAP), will very likely recover with no effects on final yield!

Cracking Time Reminders for Peanuts (Prostko)

As of May 11, 28% of the Georgia peanut crop was reported as planted.  Thus, peanut growers should now be evaluating the success of their PRE weed control programs and deciding on the need for early postemergence or "cracking" herbicide applications.  Here are a few reminders about cracking sprays:

1) If a peanut grower started clean and used a good residual weed control program (i.e. Prowl or Sonalan + Valor + Strongarm) that was activated with irrigation or rainfall, the need for a cracking spray is questionable.  Best thing in this situation is to go to the field and look to see what has escaped or not.  If the field is relatively weed-free, a cracking spray may not be justifiable.   Growers might consider waiting until 30-40 DAP to pull the trigger earlier on a POST program such as Cadre + 2,4-DB + Anthem Flex or Dual Magnum or Outlook or Warrant or Zidua.  

2) If a grower decides to use a cracking spray, I would suggest a combination of paraquat + Storm or Basagran + Anthem Flex or Dual Magnum or Outlook or Warrant or Zidua.  Suggested use rates would be as follows:

    a) 2 lb ai/gal paraquat = 12 oz/A or 3 lb ai/A paraquat = 8 oz/A

    b) Storm 4SL @ 16 oz/A or Basagran 4SL @ 8 oz/A.  If a grower wants to make his own "Georgia" Storm then use Ultra Blazer 2SL @ 16 oz/A + Basagran 4SL @ 8 oz/A.

    c) Anthem Flex 4SE @ 3 oz/A or Dual Magnum 7.62EC @ 16 oz/A or Outlook 6EC @ 12.8 oz/A or Warrant 3ME @ 48 oz/A or Zidua 85WG @ 1.5 oz/A or Zidua 4.17SC @ 2.5 oz/A.

3) If Dual Magnum or Outlook are used with paraquat + Storm or Basagran, no additional adjuvants are required.  If Anthem Flex or Warrant or Zidua are used, a NIS @ 0.25% v/v is suggested.

4) I would prefer peanut cracking sprays to be applied in 15 GPA and tractor speeds of 10 MPH or less to improve spray coverage and reduce the production of dust (which can greatly reduce paraquat efficacy). 

5) Given the option of using either an AIXR or TTI spray tip, I would prefer the AIXR tip.  

6) If growers use higher rates of paraquat and/or delay paraquat applications past 28 days after cracking (DAC), the risk for yield loss resulting from paraquat injury is increased.  Recent results from a 2018 weed-free field trial indicated that paraquat treatments applied ~35 DAC resulted in a 5.5% peanut yield reduction.

Anthem Flex Receives Peanut Label (Prostko)

Anthem Flex 4SE, from FMC, recently received full labeling for use in peanut.  Anthem Flex is a combination of pyroxasulfone (3.733 lbs/gal) and carfentrazone (0.267 lbs/gal).  I have been testing Anthem Flex for many years so there is lots of data supporting its use in GA.  Here are a few thoughts:

1) Anthem Flex will compete for market share in peanut with Dual Magnum (S-metolachlor), Outlook (dimethenamid-P), Warrant (acetochlor), and Zidua (pyroxasulfone). 

2) As far as I am concerned, there are no major differences between any of these herbicides when used in my recommended peanut weed control programs (Figure 1).

3) Anthem Flex and Zidua should only be applied POST in peanut due to crop injury concerns with PRE applications.  Either can be tank-mixed with Gramoxone, Cadre, or Cobra.  

4) Since Anthem Flex also contains carfentrazone (the same AI in Aim), higher levels of foliar leaf injury (burn) should be expected (Figure 2).  However, this increased leaf injury has not resulted in significant peanut yield losses.

5) I have tank-mixed Anthem Flex with the following fungicides: Tilt/Bravo, Abound, Fontelis, Provost, Priaxor, Artisan, and Elast.  Peanut leaf burn was increased 6%-12% when Tilt/Bravo, Fontelis, Artisan, and Elast were tank-mixed with Anthem Flex but peanut yields were not reduced.     

5) For additional information about the research that I have conducted on Anthem Flex in peanut, refer to the following PowerPoint slide presentation:
http://www.gaweed.com/slides/web-anthem%20flex/index.html

6) A copy of the complete Anthem Flex label can be obtained from the following location:
https://s3-us-west-1.amazonaws.com/agrian-cg-fs1-production/pdfs/Anthem_Flex1m_Label.pdf

  

Prowl/Field Corn, Valor/Grain Sorghum, and Balance Bean Herbicide (Prostko)

Got a few reoccurring questions over the last week, so I thought I would share a few thoughts with you:

1) I have heard that a few field corn growers have been reluctant to apply Prowl POST in field corn due to potential injury concerns, especially root pruning.  POST applications of Prowl can cause root injury but this usually only occurs when the corn seed has been planted < 1.5" deep and seed-furrow closure is not adequate.  With 21 years of data under my belt in Georgia, I am not overly worried about POST applications of Prowl causing unacceptable field corn injury (assuming correct application rate, timing, seed depth, etc.).  Figure 1 presents some recent research data from UGA which indicated that the addition of Prowl to Roundup + Atrazine did not reduce corn yields (note the very high yields).  In fact, the combination of Roundup + Atrazine + Prowl has been the standard POST program that I have compared all other newer herbicide programs to for many years (Figure 2).   

2) What about using Valor (2 oz/A) in a pre-plant burndown before planting grain sorghum???  That's perfectly legal as long as the labeled 30 day replant interval is followed.  BUT, BUT, BUT, do we really want to risk any potential increases in PPO-resistance by using Valor on a relatively minor crop in Georgia?????  I have been preaching over the last few years that we need to save Valor for cotton and peanut.  Field corn and grain sorghum are the only 2 row crops where the use of a PPO herbicide is not 100% necessary.  Thus, grain sorghum growers who want to add a residual herbicide in their burndown program, especially when planting will be delayed for a few weeks, should consider adding either Dual Magnum or Warrant.  Please remember that when Dual Magnum or Warrant are used in grain sorghum prior to planting or PRE, the seed must be treated with Concep.  

3) Balance Bean Herbicide (isoxaflutole), from Bayer CropScience, was recently registered for use on GT27 or isoxaflutole-resistant soybeans.  Because of our herbicide-resistant weed issues, there might be some grower interest in this herbicide. But, UGA Extension (i.e. me and you) will not be officially recommending its use for now due to the fact that no efficacy/tolerance data has been collected in Georgia, adapted soybean variety data is not readily available, and the label that I have recently seen only permits Balance Bean applications in 7 Georgia counties (Atkinson, Berrien, Clinch, Echols, Evans, Lanier, and Lowndes). I need to find out more information about these county restrictions and collect a bunch of local data before I would ever want a Georgia soybean grower to consider its use.    

Pigweed Emergence (Prostko)

Just a heads up to you and your growers that Palmer amaranth has already emerged in the field (Figure 1).  Consequently, strip-tillage peanut growers who are applying burndown herbicides (Roundup, Gramoxone, 2,4-D) now should seriously consider including a residual herbicide with the burndown.  I would suggest either Valor SX 51WG @ 2 oz/A or Dual Magnum 7.62EC @ 16 oz/A.  Residuals included with the burndown herbicide program should help keep peanut fields pigweed free until planting.

Figure 1. Palmer amaranth emergence at UGA Ponder Farm (Ty Ty), March 19, 2020.

Using Pesticides Wisely (UPW) - 2020 Update (Culpepper and McCann)

Agents, by now you should be aware that all in-person UPW classroom trainings have been cancelled.  Fortunately, several of our locations were able to complete their trainings.  And even more importantly, because of your hard work and a great grower effort, about 95% of those individuals applying Engenia, Enlist One, Enlist Duo, Fexapan, XtendiMax, and Tavium are not required to attend a training session during 2020.  For those still needing to be trained, UGA Extension and the Georgia Department of Agriculture are currently developing an effective approach that will fulfill training requirements.  Dr. McCann will host a Zoom meeting with ANR Extension agents in the very near future to discuss the plan and logistics.  Additionally during this call, we will discuss the registration challenges facing dicamba and what we in Extension can do to assist our growers in making very intelligent decisions during 2020 when applying all pesticides.  Please make sure to attend the call.

2020 Field Corn Hybrid Herbicide Tolerance Information (Prostko)

Some good information to keep in your truck about the tolerance/sensitivity of field corn hybrids to certain herbicides. A very good idea for field corn growers to check this information BEFORE an herbicide application is made.

1) Pioneer

https://www.pioneer.com/content/dam/dpagco/pioneer/na/us/en/products/files/corn/DF_Corn-Hybrid-Herbicide-Response-Ratings-Product-List.pdf

2) Dekalb (had to make my own chart for these)

2020 Dekalb Field Corn Hybrid Herbicide Sensitivity Ratings – Georgia

Hybrid (DKC)	Herbicide Class
	Growth Regulators	Sulfonylureas	Isoxazoles (HPPD)
62-05	C	W	A
62-06	C	W	A
62-08	C	W	A
63-57	A	A	A
64-25	A	A	A
64-32	A	A	A
64-34	A	A	A
64-35	A	A	A
65-18	A	C	A
65-20	A	C	A
66-59	A	A	A
66-94	A	A	A
66-97	A	A	A
67-14	A	A	A
67-42	A	A	A
67-44	A	A	A
67-58	C	A	A
67-70	A	A	A
67-72	A	A	A
68-24	C	A	A
68-26	C	A	A
68-68	A	A	A
68-69	A	A	A
69-16	A	A	A
70-01	A	C	A
70-25	A	A	A
70-26	A	A	A
70-27	A	A	A
70-64	A	A	A

A = Acceptable: Either no adverse effects from the corn product/herbicide combination were noted on any traits or only slight damage could be noted under adverse conditions or herbicide application at higher than label rates. C = Caution:  The corn product/herbicide combination is usually not a problem if sprayed according to label directions, but can result in plant height reductions, stand loss and suspected yield loss under very adverse environmental conditions, high rates or extreme soil pH levels or organic content. Use drop nozzle spraying for postemergence herbicides to avoid interactions. W = Warning: Not advised–this corn product/herbicide combination should not be used under any circumstances.

3) AgriGold (pages 70-71)

http://agrigold.com/Content/pdf/FlipBook/Hybrid-Profile-Guide-2019-20.pdf