What is in this article?:
- How to manage glyphosate-resistant Italian ryegrass
- Tillage, Gramoxone Inteon
- Ditch banks, field borders
- Scouting fields
- Residual herbicides in fall offer best chance for reliable control.
- Dual Magnum, Treflan, Command most consistent at Stoneville.
- Agressive tillage or Gramoxone Inteon for emerged ryegrass.
- Control on ditch banks, turn roads, field borders.
- Scout early to determine spring options.
Tillage, Gramoxone Inteon
Control emerged glyphosate-resistant Italian ryegrass in the fall with aggressive tillage or application of Gramoxone Inteon.
None of the residual herbicides available for glyphosate-resistant Italian ryegrass have postemergence activity. Should the current weather pattern change and ryegrass begin emerging, these emerged plants must be controlled before the residual herbicide is applied.
If the field has not already been tilled in preparation for next year, then the first flush could be destroyed during this tillage operation. When relying on tillage to control emerged Italian ryegrass, pay close attention to the clods behind the disk.
To completely kill Italian ryegrass seedlings, the clods must be crumbled and not just turned over. Emerged glyphosate-resistant Italian ryegrass will survive on the clods if they are not sufficiently crumbled.
Because destroying glyphosate-resistant Italian ryegrass with tillage in the fall may require an additional, unplanned pass across the field, then controlling emerged plants with Gramoxone Inteon (plus a crop oil concentrate or nonionic surfactant) may be a better option. Because ryegrass seedlings are small in the fall, the Gramoxone Inteon rate does not need to be as high as required in the spring.
Gramoxone Inteon should be applied at 4 pints per acre in the spring while 2 to 3 pints per acre should be sufficient to control glyphosate-resistant Italian ryegrass in the fall.
Gramoxone Inteon may be tank-mixed with Dual Magnum or Command. If you choose to use Treflan and emerged Italian ryegrass has been completely destroyed by tillage, then Gramoxone Inteon should not be required.
However, if the field has been worked once or twice and glyphosate-resistant Italian ryegrass emerges before the Treflan application and its subsequent incorporation, then Gramoxone Inteon will be needed.
Keep in mind that hippers often just bury emerged plants rather than killing them. Additional tillage will be required to control emerged plants prior to bedding in these situations.
When tank-mixing Gramoxone Inteon with Treflan, wait four to six hours between spraying and incorporation.
Regardless of how you choose to control emerged glyphosate-resistant Italian ryegrass in the fall, this is an absolutely critical component of the management plan and should not be overlooked or skimped on. Dual Magnum, Command, or Treflan will not kill even the smallest ryegrass seedlings. Escapes of just a few scattered one- to two-leaf seedlings in October will tiller and expand into large clumps in the spring, potentially resembling herbicide failure.