One sure way to kill forage yield is by letting invasive species like weeds and brush take claim on the land.

From the March issue of Cow/Calf Producer.

According to Dow AgroSciences range and pasture development specialist Charles Hart, since some species’ seeds can remain viable for 10 to 20 years, keeping weeds at bay is not a “one and done” deal — it’s a program.

“First thing that needs to be done is to identify what is out there,” Hart says. “Otherwise you’re going to be taking a shotgun approach, instead of the high-powered rifle approach of honing in for a direct hit. By knowing the species, the herbicide prescription can be tailored and much more effective.”

It is most common for there to be an invasion of multiple species, Hart explains. When this is the case, producers need to narrow down if the weeds are annuals, biennial or perennials. This will help in the “when, what, how and why” process for treatment and control options.

“We time the control of an annual species differently than we do deep-rooted perennials,” he says. “With annual species, we have to top-kill them and the plant won’t come back; perennial species are different. We can top-kill a perennial species and it will re-sprout from the crown of the root, so we have to change our strategy to where we’re killing the roots.”

Hart also says a big factor in weed control is land-management practices. Bottom line, if producers overgraze the land, they’re going to have weeds.

“Overgrazing and weeds go hand-in-hand, and if you manage properly from a grazing standpoint, the longevity of your weed-control program will be better,” Hart says. “And weeds compete with grass. For every weed that comes in, you’re replacing high-quality forage because water and soil nutrition are limited resources.”

Timing is everything

According to Hart, timing plays a crucial role in the effectiveness of weed control. Hart recommends the following treatment times for spraying programs:

Annuals — Spray when 4 to 6 inches of height.

Biennial — Spray prior to bolting during the rosette stage.

Perennials — More species-specific on recommendations, but tend to react best when sprayed while blooming. Keep in mind, some species will react better when sprayed post-blooming and pre-blooming.

“I would encourage producers to work with their local range and land management specialist to tailor a specific program for their environment and operation,” Hart concludes. “It’s best to get help and seek advice, so a weed problem can be taken care of as fast as possible to help their operation’s bottom line.”