"Cracking" Time Again on Peanuts (Prostko)

Many peanut growers are in the field right now making "cracking" applications of paraquat (whether they really need it or not?).  I always get tons of questions about product use rates.  Check out these pictures from earlier today.  These are rates I have been testing for years and they work pretty much all the time (when applied to small weeds 1"-3").  Higher rates and later applications, especially in dryland fields, can push a peanut plant's paraquat tolerance to its limits.   

A few other thoughts:

1) If grower wants to use the 3 lb/gal formulation of paraquat (i.e. Helmquat or Gramoxone 3SL), the normal application rate in these tank-mixtures is 8 oz/A (0.1875 lb ai/A).

2) If a grower wants to use Basagran 4SL (bentazon) instead of Storm 4SL (bentazon + acifluorfen), I would suggest using 8 oz/A of Basagran 4SL.

3) If a grower wants to make his own Storm, I would suggest the combination of Ultra Blazer 2SL @ 16 oz/A + Basagran 4SL @ 8 oz/A.

4) I am not a huge fan of using paraquat + Dual Magnum or any other Group 15 herbicide without some Basagran or Storm to cool it down some on the peanut plant.  

5) No adjuvants are needed when Dual Magnum or Outlook are used (i.e. oil-based formulations) but NIS @ 0.25% v/v (1 qt/100 gallons) is suggested when using Anthem Flex, Warrant, or Zidua.  

6) Do I use i.e. and/or italics too much???? (probably)

Monday Musings (May 16) - Prostko

 A few things from the field earlier today:

1) When you get up early, you get to see some cool stuff!

Irrigating under the "blood" moon from last night (6:31 am)

Rainbows for breakfast!  A great omen for the rest of the week (hopefully).

2) Check out the awesome power of a PRE herbicide (activated with moisture).  These are from my grain sorghum plots.  It's 2 weeks after planting and in plots that are not weedy, there were PRE applications of various residual herbicides including one of the following: Aatrex (atrazine); Moccasin II Plus (S-metolachlor); Parallel (metolachlor); Everprex (S-metolachlor); Parallel Plus (atrazine + S-metolachlor); or Cinch ATZ (atrazine + S-metolachlor).  EPOST treatments were applied today. Not sure why growers, especially those with irrigation, are often reluctant to use a PRE??????????

3) Here's what diuron injury looks like on field corn.  It took 3 days before the symptoms started to show up.  I will let you know what happens to final yield.  

4) I am seeing some good weed control results in my soybean plots with Liberty + Enlist One (applied 19 DAP, V1 soybeans, 3-6" Palmer amaranth).

5)  Peanut growers who use Anthem Flex (carfentrazone + pyroxasulfone) in their paraquat "cracking" applications should expect to see more leaf injury (cosmetic) than when Dual Magnum, Outlook, Warrant, or Zidua are used.  Based upon previous UGA research, this injury should not reduce yields.

  

Monday Musings (May 9) - Prostko

Here are a couple of things to think about based upon recent phone calls/texts and observations from some of my current research projects.

1) If growers observe unexpected/unusual leaf injury/burn after a corn herbicide is applied, it is most likely caused by Valor sprayer contamination.  See below for what this injury looks like and how it could potentially influence corn yields. 

2) When evaluating the potential effects of Liberty on pigweed control, growers should wait at least 7 days before making a final decision on whether or not it worked.  FYI, the colder temperatures this week (< 60 F) will slow down the activity of Liberty for sure.  

3) Peanut growers will be making the decision to spray or not spray an early-postemergence (cracking) herbicide.  If the peanut field was clean at planting and a strong residual herbicide program was used (activated with moisture), it is very likely that a cracking spray will not be needed.  See below (i.e. no weeds in my standard PRE program at 12 DAP):

4) My general recommendations for early-postemergence (cracking) treatments in peanut are as follows:

a) Either paraquat (2 lb/gal) @ 12 oz/A or paraquat (3 lb/gal) @ 8 oz/A + either Storm @ 16 oz/A or Basagran @ 8 oz/A + one Group 15 herbicide [either Anthem Flex @ 3 oz/A or Dual Magnum @ 16 oz/A or Outlook @ 12.8 oz/A or Warrant @ 48 oz/A or Zidua @ 2.5 oz/A (liquid)]. 

Generally, I have no preference between the Group 15's when my suggested PRE/EPOST/POST peanut weed control programs are followed.

b) Add NIS @ 0.25 v/v when using Anthem Flex, Warrant, or Zidua.

c) If need be, growers can make their own Storm (I call it Georgia Storm), by tank-mixing Ultra Blazer (16 oz/A) + Basagran (8 oz/A). This is a slightly different rate than what is applied with current commercial Storm formulation @ 16 oz/A (equivalent to Ultra Blazer @ 11 oz/A + Basagran @ 11 oz/A).

d) Use at least 15 GPA and pressure/nozzle configurations to produce medium to coarse droplets (236-403 microns).  Medium/coarse droplets are yellow and green on this chart.

e) Excessive dust caused by dry weather and tractors driven at Warp Speed 10 will reduce the effectiveness of paraquat.  

NOTE:  Click on pictures for a better view.