We have been getting many calls this past week about odd patches showing up on semi-dormant bermudagrass putting greens. Microdochium patch (formerly Fusarium patch) is a foliar disease caused by Microdochium nivale. This fungus also is the causal agent of pink snow mold. The covers used to protect bermudagrass greens create the same environment as snow cover, which is a perfect environment to activate the fungus. When environmental conditions become moderate (50s to 60s) and rainfall is plenty, M. nivale begins to infect the leaves of the bermudagrass. The fungus is spread via small spores (see image on left) that move in the water film associated with the turf canopy. When conditions become dry, the spread of disease slows down.
So, what can you do to prevent or reduce disease pressure?
Make a note of Microdochium patch occurrence so you can be ready next year. Prior to covering the greens, you may apply a DMI or a strobilurin fungicide. If the disease is active such as now, a penetrant fungicide labeled for Microchochium patch should be effective. This is a late winter disease that may also occur in the spring if excessive precipitation and moderate temperatures occur. However, it is strictly a foliar disease, causing reduced aesthetic quality to the bermudagrass putting greens. The turf will recover and grow out of the disease symptoms as spring green-up progresses. If your situation allows, let mother nature take its course.
Not sure what those crazy symptoms are on the greens? A disease diagnosis is an important step in disease management. For confirmation of a disease, send a sample to your friendly diagnostician. With a disease diagnosis, you can develop an effective cultural and chemical management approach to reduce or prevent further damage to the turfgrass.
Got questions? Consult with your Mississippi State University Turfgrass Team!