During the last month I have had several calls about the proper timing to spray Roundup Ready alfalfa varieties with Roundup. This is reported in the new “Weed Control in Alfalfa” publication highlighted in last months issue. It states “the initial
glyphosate application is necessary at the 3 to 5 trifoliate leaf stage to remove the small percentage of glyphosate-susceptible alfalfa plants that can be present in a new seeding (and to kill any weeds present in the stand). Spraying at the 3 to 5 leaf stage insures that all alfalfa seedings have emerged. But if weeds are present at earlier stages of alfalfa growth Roundup can be sprayed on Roundup Ready alfalfa from emergence up through any stage of plant growth.