Recovering from Snow Mold Damage

Pink Snow Mold (Michrodochium nivale) and Grey Snow Mold (Typhula incarnata and Typhula ishikariensis) are the diseases that plague golf courses and test the resolve of superintendents across Canada.  These fungi naturally live in the soil/thatch.  Our harsh winter environments are ideal growing environments for the fungus which incubates under the snow throughout the winter.  The longer the winter and more consistent the snow cover, the more severe the damage can be.  This past winter, snow arrived in late October and didn't leave the property until late April (very heavy snow mold pressure).  As turf managers, we combat this perennial problem through chemical applications.  Fungicide is applied to playing surfaces to protect the grass from the resulting injury.  Here at River Bend we applied fungicides to our greens, tees, surrounds, approaches, and fairways to provide the turf adequate survival capabilities through the winter.  Areas that were treated wintered very strong and came out in the spring looking very good.  Unfortunately due to the cost of these products not all fairways were treated.  This resulted in some severe snow mold damage this spring in the areas that were untreated when compared to those that were treated.

 

 #6 Fairway (UNTREATED)

 

#7 Fairway (UNTREATED)

 

#9 Fairway (TREATED)

 

#10 Fairway (TREATED)

 

#8 Approach / Fairway

 Left:  UNTREATED                      Right:  TREATED

 

The issue now becomes recovering these fairways to reasonable playing conditions.  How do we do that?  Our cultural practice schedule has us verticutting, aerating and/or topdressing fairways throughout the season.  The reason we do these processes is it to reduce the thatch levels, introduce air into the soil profile (root zone, and encourage vegetative (lateral) growth.  The heavy levels of thatch in our fairways not only reduce firmness, water penetration, and fertilizer efficacy, but also provide an ideal location for this patogen to sit and wait until the next snow cover.  In conjunction with verticutting the fairways we are also overseeding them to provide new seedlings that will eventually, over time, fill in the voids on the fairways.  This is by no means a quick fix.  It takes time to reduce thatch levels and get grass to grow into these vacant spots.  This process will take place a couple times throughout the season to provide a good seed bank as well as encourage lateral growth.  With warm temperatures scheduled to hit and adequate moisture maintained we will hopefully see marked improvements by season's end.  At which time, if revenue allows, we will attempt to treat additional fairways with fungicide inevidtably giving the turf a better fighting chance this upcoming winter, which will help improve our conditions the following spring.

 

Fairway Verticutting Results

Fairway Overseeder

 

Seed Lines (in slits)