Differences in Roundup Ready Alfalfa Varieties

Roundup Ready (RR) alfalfa varieties have been widely available for several years in Kentucky, but we now have enough yield data to accurately compare RR variety performance. Look on page 1 of the “2016 Long-Term Summary Report2016 Long-Term Summary Report” to choose the best variety to purchase. Many hay producers tell me that they would like to plant a RR variety, but they also want a mixed grass stand. In this case, simply plant a RR variety as a pure stand and clean up weeds with Roundup for the first 1 to 2 years. Then interseed orchardgrass or another grass species in the fall for a weed-free mixed alfalfa/grass stand. One producer told me he sprayed his mixed hay field with Roundup in year 4 (killing weeds but also the orchardgrass) and then interseeded orchardgrass again that fall producing a vigorous weed-free mixed alfalfa/grass stand for 3 more years.