What is in this article?:
• It’s difficult to tank-mix more than two materials and make an application at the best time to provide optimum control of the target pests.
• Usually tank-mixing requires the grower to determine whether he or she can live with less than complete control of one or more pests.
• Sometimes the reduction in control is due to a lack of compatibility of materials in the tank-mix.
DAMAGING THE plant can compound tank-mix problems when mixing grass and broadleaf herbicides.
Could be problems
On the other hand, if the weeds are larger than optimum and the efficacy is reduced, there could be problems with the tank-mix, Jordan says.
Despite many well-documented reasons why tank mixes can be a concern, there are plenty of good reasons to make a single application of multiple products, with savings in time and labor at the top of the list.
Herbicides mixed with herbicides provide the most problems, but there are several tank-mix options that do work, Jordan says.
“Paraquat mixed with Basagran is an example. If you need to reduce paraquat damage on peanuts, add a half pint of Basagran to reduce injury. If you have yellow nutsedge in a field or perhaps prickly sida, bump the Basagran up to a pint per acre or more to enhance control, he adds.
“In the pigweed world we’re living in today, there is a need to put out more residual herbicides at planting, incorporated or at early postemergence.
“If you do that, be aware you will almost always see more injury when Dual or Outlook is applied with paraquat even when Basagran is included.
“That’s not the end of the world — there will be more than normal injury symptoms, but yield will not be affected,” Jordan says.
Occasionally, when there are grass escapes, Basagran sometimes decreases the activity that paraquat would normally have on grass, he adds.
“In peanuts, if you have excessive damage from thrips, growers should not apply paraquat — significant yield reductions can occur in this case.”
With Temik not available for the 2012 growing season, the North Carolina specialist says researchers have ramped up tests with Orthene and other insecticides applied to emerged peanuts, to see how it fits in cases where in-furrow applications don’t work as well as desired.
In most cases tank mixes with Orthene and early postemergence herbicide applications have worked out fine — there doesn’t seem to be any significant damage or loss of efficacy with these tank mixes.
For grass control, Select and Poast and a number of generic versions of each have been around a long time and provide excellent grass control in a wide range of crops.
However, if these materials are tank-mixed with broadleaf herbicides, like Cobra, UltraBlazer, or Storm, you will get a 20-60 percent reduction in grass control.
Growers with major pigweed issues can use Dual and Outlook with grass herbicides and there seems to be no adverse compatibility issues with these materials, at least not in tests we’ve looked at so far, Jordan says.
In general, he adds, there have been few, if any problems when tank-mixing broadleaf herbicides like Cobra, Cadre, Pursuit or 2,4-DB, with an insecticide or fungicide.
Maybe an odd problem here or there, but in general we don’t see problems when tank-mixing broadleaf herbicides with other pesticides, he adds.