Georgia: 4 Weed Management Considerations

Poorly controlled pigweed following dicamba applications. Photo: University of Tennessee

Poorly controlled pigweed following dicamba applications. Photo: University of Tennessee

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. 

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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.  

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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):

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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.

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

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Source URL: http://ugaweedscience.blogspot.com/2022/05/monday-musings-may-9-prostko.html