Halex GT Mixing Problem in Corn/Valor Applied PPI (Prostko)

 A couple of things to bring to your attention based upon my week:

1) A field corn grower in Macon Co. experienced a significant problem when Halex GT (mesotrione + S-metolachlor + glyphosate-K salt) was tank-mixed with a different type of glyphosate formulation (IPA salt) (Figure 1).  This problem did not occur when other K salt formulations (Roundup PowerMax3 or Honcho K6) were used (Figure 2). Remember that all glyphosate formulations are not created equal.  They have different concentrations of active ingredients, are formulated as different salts (K, IPA, DMA), and may/may not be formulated with adjuvants. In my April 8 blog, I provided you with a couple of links where you can get some handy information (charts) about the different glyphosate formulations.

Figure 1.  Halex GT tank-mixing problem in Macon County, 2024.

Figure 2.  Different glyphosate formulations tank-mixed with Halex GT + Atrazine +
Mustang Max + NIS + Defoamer

2) Please remind your growers that UGA does not recommend that Valor be applied pre-plant incorporated (PPI) for weed control in peanut!  Valor is not labeled for that type of application and pigweed control will be significantly reduced (PPI is 25-35% less effective than when applied PRE behind the planter).   

 

Figure 3.  Palmer amaranth control in peanut with Valor applied PPI or PRE.