Weed control after asparagus harvest
Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.
Asparagus harvest is complete or almost complete in most areas of the state. This is a critical time for herbicide application for control of perennial and herbicide resistant weeds. For control of perennial broadleaves, apply dicamba (Banvel, Clarity), 2,4-D (Formula 40), halosulfuron (Sandea) or glyphosate (Roundup) immediately after the final harvest. All of the herbicides except Sandea can injure asparagus if too much is absorbed by the spears or fern. Waiting one or two days after final harvest before application may result in excessive spear twisting and curling.
A preemergence herbicide should be applied after harvest also. Choose a residual herbicide or combination of herbicides with a different mode of action from that used before emergence in the spring. Karmex, Sencor (PSII inhibitors), Dual Magnum (cell division inhibitor), Callisto (HPPD inhibitor and Sandea (ALS inhibitor) are labeled for application after harvest. Dual Magnum is the most effective grass herbicide of these, but also has the shortest residual period. Callisto will cause some bleaching of new fern, but it does not appear to cause any long term crop damage.
See Extension Bulleting E-433, Weed control guide for vegetable crops, for more information on each herbicide. Or look up the labels on the web at www.cdms.net, and search by company.