Oklahoma foundation says to prepare now to fight next year's weeds

“Now is not the time to spray for weeds,” said Eddie Funderburg, senior soils and crops consultant for The Samuel Roberts Noble Foundation. “Now is the time to inventory them so you can spray next year.”

Weeds are easier to identify when they've had time to grow and form seed heads, he said. Knowing which type of weed grows where can make spraying more effective in the spring.

That's because the same weeds tend to pop up in the same location year after year until they're eliminated. If one section of a field is choked with western ragweed now, it's likely to have the same problem next year.

For large growers, an inventory begins by identifying the species and abundance of each weed, according to a Noble news release. Abundance descriptions can be as simple as “few,” “many,” “scattered” and more. Chart those tallies on a field map and highlight problem areas, including areas with hardy weeds or high concentrations. Armed with that information, producers know which types of herbicides to purchase and where to spray in the spring.

Inventories can also pinpoint areas with few weeds and locations where it is not ideal to use herbicides, such as clover patches.

“I've seen fields in which ragweed pretty much eliminated forage production,” Funderburg said. “A pound of weeds pretty much eliminates a pound of grass. It's a one to one ratio. So if you have 2,000 pounds of weeds, you're out 2,000 pounds of the forage plants you wanted to grow.”