Zest™ 75WDG (nicosulfuron) has received Georgia approval for use on Inzen™ herbicide-tolerant grain sorghum varieties. Grain sorghum growers who use this technology will now be able to get better POST control of Texas panicum and other grasses. Nicosulfuron is the same active ingredient in Accent, which is registered for use on field corn.
A couple of reminders from UGA Extension Weed Scientist Dr. Eric Prostko:
1) Zest can only be used on Inzen herbicide-tolerant grain sorghum varieties. The use of Zest on conventional sorghum varieties will result in crop death! Inzen grain sorghum varieties are not GMO’s.
2) The current formulation of Zest is a WDG. I have been testing a liquid formulation so rates would be different in any slides you have previously seen from me.
3) UGA has limited variety performance data (i.e. none). As far as I know, the only company with Inzen varieties is Advanta/Alta (http://altaseeds.advantaus.com). Pioneer will likely have some varieties in 2018 or 2019? Thus, I would suggest Georgia sorghum growers proceed with caution until an adapted variety is identified. I have not been overly impressed with the varieties that I have been testing up until now.
4) I would still recommend the use of Concep treated seed + a PRE application of Dual or Warrant in this system. Atrazine should be tank-mixed with Zest to improve the control of broadleaf weeds.
5) A copy of the complete Zest label can be accessed from the following location: