If dandelions are causing major problems in any of your no-till fields, the best time to control them for the 2004 cropping season is unfortunately already past. That’s because recent research indicates the best time for you to try to control this little yellow weed in your no-tilled fields is in the fall.
“Dandelions are strictly a no-till problem,” says Jim Kells, a Michigan State University weed scientist. “It is a simple perennial that reproduces by seed with a taproot that can overwinter. Like a lot of perennial weeds, it takes 3 to 5 years for dandelions to get established by seed, and then they can cause a serious problem. Unfortunately, no-till fields are the perfect environment for that.”
The long, fragile dandelion taproot is easily controlled by conventional tillage that breaks up the root. Yet in no-till fields, Kells says, the roots take hold and maintain the dandelion plants year after year. “I’ve seen alot of no-till fields, including our own demonstration plants, that are just a yellow carpet of dandelions,” he says.
Kells and graduate student Aaron Franssen have 3 years of results on determining which herbicides work best and when they should be applied for maximum dandelion control. They compared various rates and application timing with glyphosate and 2,4-D — two of the more effective herbicides for dandelion control. The herbicides were applied in early fall, late fall, early spring and late spring. Some plots received only one…