At a Monsanto Roundup Ready 2 Xtend field day in Collinsville, two things were abundantly clear.
First, glyphosate-resistant Palmer amaranth is extremely difficult to control. Second, due to the USDA requesting an Environmental Impact Statement, Monsanto's dicamba-tolerant soybean crop technology likely won't be commercially available until 2015 or later, pending regulatory approval.
Despite the bitter taste from these two points, there was a bright spot. The Roundup Ready 2 Xtend plots were clean of Palmer amaranth. That's an impressive feat, considering how bad the untreated check plots looked.
Another bright spot was learning a bit more about how this new crop technology will work once it's released.
John Willis, technology development manager for Monsanto, explains the herbicide component of this crop system will be available in two different low-volatility formulations. The first is a pre-mixed product that includes glyphosate, dicamba and a surfactant. It's called Roundup Xtend.
Willis notes Roundup Xtend's recommended rate will be loaded with 1 lb of glyphosate and 0.5 lbs of dicamba.
If a farmer wishes to tankmix his own herbicide program, the dicamba component is available separately as Xtendimax. Willis explains the recommended rate is 0.5 lbs of dicamba per acre. Xtendimax is not loaded with a surfactant.
In trials, Willis says the dicamba component of these herbicides provided residual activity for an average of 14 days after application.
"Dicamba is water soluble, so it actually has a longer residual activity in dry soils," Willis notes.
He adds that typically residual herbicides need about a half inch of rain to work. Dicamba requires very little moisture for residual control.