Silver-Thread Moss

Moss is often difficult to manage on golf course putting greens. In some severe cases, it can completely infest an entire putting surface within just a few months. The onset of moss issues have increased on golf courses in the past several years. Most believe that this is a direct result of the restriction of mercury-based fungicide, the stress caused by the lower fertility levels, and reduced cutting heights brought on by the demand for ever-faster greens. Staying true to cultural management techniques are essential to prevent these moss problems, but it is unlikely that the budgets will be raised anytime soon, but the demand for ever-faster greens will remain.

The infestations are thought to be spread by equipment and golfers tracking it from area to area with their spikes. In the spring, you will find the infestations residing on greens with open wounds like pitch marks, scrapes, or unhealed aerification holes. Any stress applied to the turf that would diminish the turf density or decrease the plant vigor can compound the risk of silver thread moss breakout.

Many chemicals do release some toxicity in moss, but the persistency of this plant makes long-term control difficult. Only a few chemicals have been able to demonstrate good long-term chemical control of moss, but these solutions have shown some drawbacks. Unfortunately, moss control products most often applied at regular intervals throughout the season can be very phototoxic. In addition, the timing of application impacts efficacy of the product to work.

There may be other products on the market now that work very well, but these are the products I have seen work in the past myself. The use of copper hydroxide + mancozeb (Junction) can control moss when applied on a biweekly basis at 0.2 lb/1000 ft2 with minimal phytotoxicity. Season-long application may be required on heavily infested greens, and fall applications are often most effective. Higher rates can severely damage turf. Carfentazone (Quicksilver) has been labeled for use against moss when applied twice at a 14-day interval of 6.7 oz/acre. I would recommend getting with your local chemical representative or university extension office to see what has been working best in your area.

Stay on a good fertility program; stick with your good cultural practices like topdressing on a regular basis in conjunction with a quality herbicide to keep it under control. Allowing the dead silver thread moss to remain on a green without promoting bentgrass regrowth to heal areas will allow the moss to recover and persist on that green. The use of herbicide control, proper fertilization, and topdressing have shown to be the most effective in your combat. There are several great articles on the web that will help convey this to your board or owner of the course.

If you have other products that work well for you or cultural pactices please let me know. lsharp@tee-2-green.com

4-28-11
A good friend and superintedent from Switzerland sent me another product for moss.
Royal Mogeton Herbicide Thanks Jean