Alite 27 – Residual Herbicide for GT27 Soybeans

By Mark Loux, OSU Extension State Weed Specialist, Adapted from C.O.R.N. 2022-05

Alite 27 is isoxaflutole (Balance Flexx) repackaged and labeled for preemergence use in LL-GT27 soybeans, minus the safener, cyprosulfamide, which protects corn from injury.  The LL-GT27 soybean has resistance to glyphosate, glufosinate, and isoxaflutole, and is the only type of soybean that can be used with Alite 27.  Isoxaflutole has been used as a residual herbicide in corn for quite a while, but mostly in Corvus now, where it’s combined with thiencarbazone and cyprosulfamide.  While there are many residual premixes for soybeans that control/suppress grasses and broadleaf weeds, Alite 27 probably has a broader spectrum that any other single active ingredient product.  Alite 27 can provide about 70% initial control of many annual grasses, and we rate it an 8 or 9 on most broadleaf weeds.  It can provide about 60% initial control of burcucumber and giant ragweed (at least the early-season emergers).  Many populations of common and giant ragweed in Ohio have at least some degree of resistance to site 2 herbicides (ALS inhibitors – chlorimuron, cloransulam, etc).

This results in a complete lack of residual herbicide options for control of giant ragweed, and only flumioxazin for common ragweed.  So – one of the fits for Alite 27 is to improve residual control of these ALS-resistant weeds, as long as the right soybean is being planted.  We have conducted limited research to determine whether there’s a benefit to mixing Alite 27 with other residual herbicides, and determined it’s probably not necessary in many fields that are receiving an adequate follow up POST herbicide treatment.  Adding another herbicide could help with resistance management and improve control of grasses and waterhemp.

Aside from being useful only in GT27 soybeans, the other catch is that Alite 27 is currently labeled for use only in certain Ohio counties.  We don’t know the reason for this.  These counties are:  Allen, Auglaize, Belmont, Carroll, Columbiana, Crawford, Darke, Guernsey,Hancock, Harrison, Lake (are there soybeans here?), Mercer, Monroe, Morgan, Morrow, Muskingum, Noble, Preble, Richland, Shelby, Van Wert, Washington, and Wyandot.  For more info, check the weed control guide and the Alite 27 label.