Now’s the Time to Begin to Take Out Your Annual Ryegrass Cover Crop
1. Timing is important. Late March – Mid April, depending on Midwest location
a. Burndown when the plant is 6 – 12”, before 1st node develops
b. Allow 5 – 7 days after annual ryegrass has begun to actively grow before spraying
2. Temperature is crucial. Should be above 60° F
a. Spray on a sunny day if possible
b. Wait a few days if nighttime temps dip below 38°F
c. Soil temperature should be above 45°F
d. Stop spraying about 4 hours before sunset to allow for max. translocation within the plant.
3. Coverage. Be thorough, use medium spray droplet and moderate pressure
a. Use flat fan nozzles, at 30 – 40 psi
b. Don’t use air induction nozzles that produce a course droplet size.
4. Primary application. One application of glyphosate may be enough for burndown
a. However, plan for two applications, using herbicide with a different mode of action
b. Scout the fields afterwards to ensure annual ryegrass is dead (it may look brown but can grow back)
c. Glyphosate use. Apply at 1.25 – 1.5 lb. a.e./a
d. Add ammonium sulfate and a surfactant
e. Adjust pH and follow mixing directions on the label carefully
f. When using additives, mix them first for 3 – 5 minutes in a full tank of water, before adding the glyphosate; water should be free of clay particles.
5. Precautions, and other herbicides to use when planting corn
a. Never mix atrazine or Callisto with glyphosate (ryegrass control will diminish)
b. Adding 1lb a.e./a Princep (simazine) improves weed control (not in sandy soil)
c. Use of Balance Pro, Prowl H2O, Resolve Q or Basis Blend, 2,4-D, Axiom at full label rate for residual weed control.
6. Use of other herbicides when planting soybeans
a. After beans emerge, annual ryegrass escapes can be controlled with full rates of SelectMax, Poast Plus or Fusilade DX.
b. Use fertilizer, surfactant, crop oil as label-directed. Less effective in cold temps.