G.L. Graham and W. Brown
Abstract: Growers have adopted Roundup–ready cultivars due to ease of weed control and adequate hybrid
choice. for optimum weed control and yield protection, glyphosate should be applied early in the season, typically at
the 3–5 leaf stage of corn. Growers are concerned with late season weed escapes and an application of
glyphosate at the 3-leaf stage may not control late season weeds. A trial was initiated in a commercial corn field near
Keswick Ridge, New Brunswick to evaluate the use of glyphosate with soil–residual tank mix herbicides. No
significant crop injury was noted and overall weed pressure was low in the trial area. Most tank mixes with glyphosate
had significantly improved weed control within the first two rating periods, whereby a second flush of weeds was
controlled by the residual nature of the tank mix treatments. This improvement dissipated by the final rating period,
except for the glyphosate/s–metolachlor/atrazine treatment. The conventional standard, foramsulfuron +
dicamba/atrazine, had similar weed control to the glyphosate treatments. The additional cost of a tank mix partner, in
relation to a second glyphosate application, as in the split application, should be evaluated by producers.
|