Spring is a good time to control emerged winter weeds and apply residual herbicides to control the first flush of warm-season weeds. For many years, paraquat herbicide has been utilized to control Italian ryegrass, rescuegrass, timothy grass, and some broadleaf weeds. With paraquat-resistant Italian ryegrass present in some areas, fall/winter applications of residual herbicides have been common. In situations where paraquat-resistant Italian ryegrass has emerged, Envoke at 0.3 - 0.5 oz/A in combination with asulam at 2 qt/A plus nonionic surfactant or crop oil concentrate can provide sufficient control. In situations where paraquat-resistant Italian ryegrass is not present, paraquat can be utilized. For improved burndown and soil residual activity, atrazine, diuron, hexazinone plus diuron, or metribuzin can be tank-mixed with paraquat. Please note that paraquat can be applied to sugarcane with no more than four leaves. Annual bluegrass is another common winter grass that can be present in sugarcane fields during the spring. It is easily controlled with atrazine, diuron, hexazinone plus diuron, metribuzin, or paraquat.

Broadleaf winter weeds can be controlled with 2,4-D, dicamba, a combination of 2,4-D and dicamba, or Trycera. Residual herbicides can be tank-mixed with 2,4-D, dicamba, or Trycera to improve broadleaf weed control and provide residual weed control. To maximize the effectiveness of auxin herbicides, the air temperature should be at least 65°F during application. Mesotrione at 3 oz/A plus atrazine, diuron, hexazinone, or metribuzin is another option that will provide postemergence control of broadleaf weeds and soil residual activity.

Residual herbicides to consider for itchgrass control include: pendimethalin, pendimethalin plus hexazinone, or clomazone. Research conducted over a 2-year period showed that an early spring over-the-top application of clomazone to HoCP 14-885 and L 01-299 plantcane had no effect on yield. For additional information, please refer to the Louisiana Suggested Chemical Weed Control Guide or the herbicide label.