Farmers looking to grow highly productive pastures and hay fields still have time to control weeds to prevent reduced forage quality and quantity, an Ohio State University Extension expert said.
Fall can be a good time to eliminate hard-to-control perennial weeds because many of the plants are feeding their root systems, which allows applied herbicide to reach the root system to effectively kill the weeds, said Mark Landefeld, an OSU Extension educator in Monroe County.
“Farmers should monitor their fields regularly to identify weeds and deal with them in a timely manner,” he said. “Not only can weeds decrease forage quality, but some can be invasive and reduce the tonnage of the forage that you are trying to harvest.
“Getting rid of weeds while they are small and few in number can save time, money and effort.”
The savings are significant, considering that more than 95% of weeds can be controlled through good management practices, Landefeld said. Some of the weeds to control now include chickweed, henbit, purple deadnettle, and Canada thistle.
The drought conditions this year also have resulted in more weeds in some cases.
“Often during a drought year, sunlight reaches soil surfaces that have been newly exposed due to grass that has gone dormant or because livestock have eaten it down close to the ground,” Landefeld said. “This allows more weeds to germinate.”
Chickweed, henbit and purple deadnettle infestations can cause alfalfa stands to lose up to 30% of the stand, he said. If these weeds persist and then die, that could foster additional summer annual weeds such as foxtails, lambsquarter and pigweed to take over.
While herbicides often can be used to combat hay field and pasture weeds, farmers should make sure to evaluate the existing stand in case reseeding is a better option, he said.
More information can be found in a 15-minute presentation Landefeld developed, online at http://go.osu.edu/fallweed.