Killing Annual Ryegrass
Annual ryegrass is an outstanding cover crop for building soil health. The goal is a successful control following the first herbicide application. There are several key factors to keep in mind when it comes to terminating this cover crop.
- Glyphosate requires a minimum air temperature of 60 degrees
- Soil temperature should be 45 degrees
- Spray after the dew is dry and stop by mid-afternoon to allow 4-5 hours of sunlight for herbicide to translocate
- Allow your stand to be completely green and grow 6 to 12 inches tall; before the 1st node develops
- Allow 5-7 days after annual ryegrass has begun to actively grow before spraying. A good indicator of this is your lawn- if you have not mowed your lawn, it is probably too early to be killing annual ryegrass.
- Growing conditions should be good
Purdue specialist: Wait for warmer weather to terminate cover crops
"Producers who haven't yet terminated their cover crops should now wait for warmer weather before applying herbicide." Bill Johnson, a Purdue Extension weed scientist says.
- Click here to read a press release from Purdue extension.
Herbicide use for Annual Ryegrass
- Apply at 1.25 - 1.5 lb. a.e./acre
- Add ammonium sulfate and a surfactant
- Adjust pH and follow mixing directions on the label. 5.5 pH or lower is recommended
Percautions when planting corn
- Never mix atrazine or Callisto with glyphosate
(ryegrass control will diminish)
- Adding 1 lb. a.e./acre Princep (simazine) improves weed control
- Use of Balance Pro, Prowl H20, Resolve or Basis, 2,4-D, Axiom at full label rate for residual weed control will not affect annual ryegrass termination
Precautions when planting soybeans
- Annual ryegrass escapes can be controlled post emergence with full rates of SelectMax, Poast Plus, or Fusilade DX.
- Use fertilizer, surfactant, crop oil as label directed
After the crop emerges, escapes can be controlled in corn with labeled rates of Accent Q, Steadfast Q, or Option, but best control is obtained with these products when temperatures are above 70 degrees.