New Herbicide Technology Approved for Sorghum

By Sorghum Checkoff Agronomy Director Brent Bean, Ph.D.

The sorghum industry received a much anticipated Christmas present in 2020 with the EPA approval of IMIFLEX herbicide use in igrowth® sorghum. IMIFLEX, a UPL product, will be a welcome addition to the arsenal of herbicides sorghum growers will have available to them in 2021. So what is IMIFLEX and igrowth® sorghum?

igrowth sorghumIgrowth® is the technology, or trait, for sorghum which is resistant to the imidazolinone class of herbicides. The trait was incorporated into grain sorghum hybrids by Advanta using conventional non-GMO breeding techniques. The technology was first approved in Australia and Argentina where it has been used since 2018. In the U.S., Advanta will be selling igrowth® sorghum under Alta Seeds’ brand in 2021.

Advanta will be offering five igrowth® hybrids for the coming growing season. These hybrids fall in the medium-early to medium maturity range; however, growers should be aware none of these first generation igrowth® hybrids will have good sugarcane aphid tolerance.

The active ingredient in IMIFLEX is imazamox, which some growers may be familiar with as Raptor that is used in soybeans. One of the positives of IMIFLEX is that it has both PRE and POST-emergence activity. When IMIFLEX is applied will likely depend on the dominant weed species growers desire to control. The herbicide will have activity on both broadleaf weeds and grasses.

Growers are especially excited about the ability of IMIFLEX to control grass in sorghum. Grass control, especially POST-emergence control, has long been an issue for sorghum growers. IMIFLEX will control a number of grass species with either a PRE or POST-application.

Like other herbicides, IMIFLEX should not be considered a standalone herbicide. For grass control, always apply a group 15 herbicide (s-metolachlor, acetochlor, dimethenamid) PRE-emergence, regardless of if IMIFLEX is to be applied PRE or POST-emergence. For broadleaf weed control, other herbicides applied PRE-emergence like atrazine or mesotrione should be considered depending on soil type. As is the case with all POST-applied herbicides, weed type and size are important. Treat broadleaf weeds and grass when they are small.

For more information on igrowth® hybrids, check with your Alta Seeds representative. Questions on IMIFLEX herbicide can be answered by UPL.