Winter diseases of turf in our area are fairly predictable and range in severity from one season to another and normally do not cause the widespread turf loss that some summer disease patterns can. The drier the winter season the better, creating optimal cool season turf conditions with virtually non-existent disease pressure. However when we get the kind of constantly wet, low sunlight patterns that we have been getting, disease pressure can mount.
Red thread is a disease that is common in most winters and early springs and we normally see it in fairways and rough-cut. Severe infestations can require fungicide applications but normally a little sun and / or a little fertilizer can take care of red thread. Pink Snow Mold is another story. It can effect all turf and be very problematic on putting surfaces. It predictably rears its ugly head during wet dark winters and if left unchecked can cause a lot of problems. You might have noticed some snow mold from the pictures above on our greens. We had an outbreak a couple of weeks ago but were able to immediately get it under control.
The situation that we are most concerned with due to the prolonged wet and dark conditions is a thinning on portions of certain putting surfaces. Areas most effected are the left-hand side of #3, #6, #13 & #14 along with the right side of #9 and the rear of #15. Because of the widespread symptoms on #3 & #6 we suspected a mystery winter disease so we sent off a turf sample to UC Riverside for analysis. The results of the analysis were negative for pathogen activity on both foliage and roots of the sample, which is good news.
The only assumption as to the cause of the current thinning, absent a positive disease diagnosis are environmental causes. We raised the height of cut on our greens mowers many weeks ago which is standard during winter months, and raised them even more this past week in response to the thinning. This will allow for some more leaf surface to develop that can photosynthesize and provide food for the plant with the hopeful presence of some sunlight. We have also suspended rolling the greens until they recapture a semblance of health. We are going to attempt to lightly spike the greens, as the weather dictates, providing some necessary air to the upper water logged portion of the surface along with some strategic fertilizer applications, which should perk thing up. What we really need is that which we have absolutely no control over and that is sun light.
For every action there is a reaction and the above-described measures will regain a healthy condition but will contribute to a slower surface. Bottom line the wet conditions are the main culprit for a temporary lapse in putting quality and health. Obviously this is a temporary situation for the sun will be shining before we know it. Hopefully we will get some of it soon.
|More wet weather snow mold #4 fairway|