Late Management of Cereal Rye with a Roller-Crimper
Posted: May 26, 2011
A roller-crimper terminates a mature cereal rye cover crop at Penn State's Rock Springs Research Farm.
In order to effectively kill rye with a roller-crimper and not depend on herbicides, you have to wait until it is flowering (visible anthers) which means you are dealing with some high biomass residue. If you use herbicides, glyphosate is very effective at killing rye at almost any growth stage and the normal rate (0.75 lb. ae/acre) adequate. In our roller work, we usually spray the rye first and then wait a day or two to roll. This is a very dependable way to kill and flatten the cover crop. I have also heard about some success in first rolling the cover and then spraying it. I have not tried this, but think that it would be important to spray as quickly after rolling as possible, while the rye will still actively absorb the herbicide. We have also mowed rye with both rotary and flail mowers as control tactics. The flail mower is the more effective of the two for controlling the rye and evenly distributing the residue. However, a flail mower also chops the residue into very small pieces and can make it challenging to immediately direct seed the cash crop. When dealing with a large mature rye cover crop in a conventionally managed system (not organic), delay cash crop planting for a week or two after you kill the rye to avoid potential establishment issues. Also, cash crops like soybean that fix their own N are much more suitable for planting into high residue rye biomass than high N demand crops like corn.
A fact sheet on using the roller-crimper is available at this link.
By Bill Curran, Weed Science Extension Specialist, Department of Crop and Soil Sciences, Penn State.
Originally featured in Field Crop News, Vol 11:10.