“An ounce of prevention is worth a pound of cure.” Benjamin Franklin’s quip is just as sound today as it was when uttered 250 years ago.
The reason annual ryegrass has NOT become a problem in the Midwest, despite heavy use in the past 20 years as a cover crop, is because those using it have been careful in its use…or have been able to recover from their mistakes without too much extra trouble or expense.
So, what can go wrong?
- You let it grow too long in the spring before killing it with an effective “burndown” with glyphosate or other herbicide. Ideally, spray the crop before it gets to the “joint” stag (6 inches or so in top growth)
- You try to spray the crop before all the grass is in active growth mode. It’s important to wait until it has fully broken dormancy, perhaps a week after you notice the first growth, and after the daytime temperatures reach 55 – 60 degrees, and nighttime temperatures are consistently above 40 degrees.
- You’ve used a cover crop mix and thus the dates to spray become variable because each plant (annual ryegrass, cereal rye, vetch, clover) recover from dormancy at different times.
- You spray once but don’t kill it all off with one application. At that point, it pays to be vigilant. Letting a cover crop recover from one application of herbicide can give it tolerance to a second application. Thus, it’s very important to pay attention to the second application, in terms of products to use, timing of the application and assuring that the second burndown is effective.
For more details, contact neighbors or a trusted agronomist. And by all means, check out this free information about controlling annual ryegarss, from our website.2016 ARG as a Cover Crop – 4 page