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Some Answers to Common Questions (Prostko)

Some good, recent information from Dr. Prostko –

I can tell things are busy right now because my phone has been ringing off the hook.  Here are some quick answers to some common questions that I have gotten recently:

1) Can I spray paraquat + Storm + Dual cracking treatments on peanut at night?

For now, I would say that this might be a bad idea since there is little or no peanut data to support this type of application.  For the past 17 years, all of my cracking treatments have been applied between the hours of 6 am to 9 am.  Perhaps, night applications might be something I should look into for 2015.  Research conducted in Arkansas suggested that volunteer corn control with paraquat would be greater at sunset than at sunrise.  In Texas, cotton dessication/defoliation with paraquat was better when applied at 6:00-6:30 pm compared to earlier in the day.  However, remember that many plants experience diurnal (night) leaf movements which could impact spray coverage which is extremely important for the success of any paraquat treatment.

2) Can I tank-mix Dual Magnum with peanut fungicides to get longer residual control of Palmer amaranth?

Yes.  In 2013, I tank-mixed Dual Magnum with the following fungicides at 52 DAP (R2 stage of growth, 8″ tall): Tilt/Bravo; Headline; Abound; Provost; and Fontelis.  These tank-mixtures resulted in approximately 10% peanut leaf burn.  This injury had no effect on final yield.  A similar test is being conducted in 2014.

3) Why do I not want Georgia soybean growers to use Valor, Prefix, or Reflex PRE?

A) Georgia growers are already over-using the PPO herbicides in cotton and peanut.
B) Almost every acre of soybean in Georgia will need a POST treatment for Palmer amaranth control.  The only soybean herbicide that will provide both PRE (residual) and POST control of Palmer amaranth is Reflex.  Thus, Valor, Prefix, or Reflex PRE followed by Reflex POST is a very bad idea!!!!!!!!!
C) Georgia soybean growers should seriously consider using alternative PRE herbicides such as Dual Magnum, Warrant, or Boundary.