January 2, 2013

Are you considering planting a new field to a Roundup Ready® alfalfa variety this spring? If so, make sure you’re doing it for the right reasons.

These varieties make it easy to control most weeds; however, easy weed control shouldn’t be the only reason you plant them. Here are a few factors to consider.

• For cow-calf producers planting grass-alfalfa mixtures in hay fields, Roundup® would kill the grass as well as the weeds. In these situations, conventional varieties would be more appropriate.
   
• If you are planting oats with the alfalfa and planning to harvest the oats for either hay or as grain and straw, Roundup shouldn’t be used until after oat harvest. If a good stand of alfalfa is present after harvest, further weed control with Roundup or any other herbicide may not be needed.
   
• Also remember that keeping an alfalfa field weed-free may not always increase hay tonnage. For some feed uses, having some weeds in the hay may be acceptable. This often is true if alfalfa fields are rotated to a different crop after three or four years of production. If a good stand can be established using other weed control options, weeds often don’t become a big problem until stands get older and start to thin out.

When planning your next alfalfa planting, consider how you’ll be using the harvest and whether the added $2.50 per pound of seed for this new trait makes sense for your operation.

Bruce Anderson
Extension Forage Specialist