Winter Injury Guide

I have put together a quick little guide book for our membership to understand some of the winter turf injury sustained on the golf course this season.  Some of the injury is intentional, some is desired and some is not. Either way the guide shows in basic terms what each injury looks like and the cause of it.  Sometimes  Mother Nature provides the best selective herbicide on the market. 

Winter Injury Guide

Crown Hydration:  Occurs when large amounts of surface water from snow melt turns into ice crystals outside the plant cell (extracellular) of the Turfgrass crown tissue. As these ice crystals form and enlarge, they pull water out of the cell, which will result in dehydration. At some point a dehydrated cell and cell membrane stop functioning and the result is cell death. Many times superficial damage occurs but If enough of the cells in the crown of the plant die, the entire Turfgrass plant will die as a result.

Figure 1 Hole #5 1st Fairway Under Trees

Figure 2  Hole #6 Fairway and Rough Sheet Water Flow Areas

Desiccation: Winter desiccation is the death of leaves or plants by drying during winter when the plant is either dormant or semi-dormant. Desiccation injury is usually greatest on exposed or elevated sites and areas where surface runoff is great. Tree root completion for water also affects the quality of the Turfgrass.

Figure 3 Hole #7 Exposed South Facing Mounds

                                                                   

Figure 4 Hole #4 Tree Root Competition For Water

Selective Herbicide Kill: Selective herbicides kill specific targets, while leaving the desired turf species relatively unharmed. We are using both older and newer chemistries to control Poa Annua in our key playing areas.

Figure 5 Hole #7 Fairway Poa Kill

Figure 6 North Chipping Green PoaCure Trials

What Is The Yellow Grass In The Fairways?

Throughout the fairways there are many areas that are off color and under stress, this is an intended effect from the use of herbicide that targets Poa Annua.

The fairways have received successive applications of Velocity to help control the Poa populations and this is what has caused the visible signs of turf injury. Currently the Poa is not dead, but it is under severe stress and the plant is in shut down mode which will help the desired Bentgrass to out compete it for space in the fairways.

We will be backing down the future applications so that unacceptable turf discoloration does not persist into the upcoming Member/Guest tournament in a few weeks.

Signs of Injury

As I mentioned in an earlier post, we have been playing around with some experimental treatments to help eradicate the Perennial Ryegrass in our Bentgrass fairways.

The first visible signs of treatment began to show up after six days following the initial application. Symptoms of the treated areas began to show up as a chlorotic effect on the turfgrass.

Chlorotic Effect Shown of Fairway

Ten days after treatment another indicator that something was going also started to appear. Smaller patches of the Ryegrass are beginning to turn reddish and are giving the appearance of dying. Not all of the Ryegrass is showing the same effect, but several areas are reacting more effectively to the treatment.

Ryegrass Checking Out

Resistant To Change

We have been converting our fairways from Perennial Ryegrass to Bentgrass for the last Six seasons. Overall the conversion has gone extremely well, with Total Bentgrass populations exceeding 75% in the fairways. The other components in the fairways are Poa Annua and Ryegrass.

The reduction of Poa Annua populations has actually been easier than reducing the Ryegrass, due to chemical options currently available. The Ryegrass has persisted in heavy cart traffic areas in the fairways because it’s better equipped to handle the repeated pounding of cart traffic. It is areas like these that the Bentgrass has been slower to establish itself and we are now beginning to try alternative methods to help with the conversion.

Rygrass in Fairway(Dark Green Patches)

Currently we have begun test application to some of the fairway areas that contain high populations of Ryegrass to evaluate the efficacy of a new product. I have been speaking with a university professor about protocol of this product and I will be reporting my results to him. As with anything new, we are trying this on a limited scale to see how the product will react in our environmental conditions. If we see positive results we will increase the applications until the desired effect takes place. These applications will be timed with Bentgrass overseedings, so that any voids that might be created will have viable seed in the soil waiting to germinate and fill in.