STRI Tech Notes - Issue 9 - Post winter clean up
It's been a long, hard winter for turf. Autumn came early in 2008, with summer (if that is what we could call it) disappearing in the first week of September, to be replaced by cooler, wet weather perfectly conducive to Fusarium Patch (Microdochium Patch). Most of us were caught out and hadn't been prepared for preventative treatments (including us 'experts' here at STRI).
Fortunately, in the main October allowed a catch up period when grass was still growing enough to allow recovery and ensure it had fungicide protection for the winter.
The winter started very cold. I even thought we might see the good old days of pests and diseases being adversely affected and soil temperatures dropping below zero. However, it didn't last. Snow lying, in some cases for weeks at a time allowed pathogens to proliferate under their winter duvets. As a result, we have seen some spectacular snow mould emerge when the snow melted (below).
Many golf green and bowling greens are not looking their best following the surge in disease under the snow. As the temperatures increase, renovation can begin to get the surfaces back to full strength as quickly as possible.
Snow mould on untreated plot following 2 weeks of snow cover. Plots in the background treated with Daconil WeatherStik before the snow show almost complete control.
Where eradicant fungicides - such as Instrata Elite or Daconil Weather Stik - were applied after the snow, scarring is still very much apparent. In some cases, as the mild temperatures are returning the edges of Fusarium Patch/Snow Mould scars are becoming active again (below), leading to potential further outbreaks.
This activity should be monitored to prevent any increase in disease as soil temperatures increase and spring fertilisation begins to help grass growth. If active disease is present the use of lawn sand as the first fertiliser will help to reduce the chance of any outbreak.
If weather conditions become conducive to the disease, a fungicide application may be necessary. Soil temperatures will influence your choice of fungicide, as systemic products need the grass to be actively growing and soil temperatures may fluctuate up and down early in the growing season.
In cool conditions contacts - such as Instrata and Daconil - are the initial options, before switching to systemic fungicides - such as Heritage - as grass growth speeds up. Check out Greencast for current and 5 day forecasts of soil temperatures in your area.
Once the soil temperatures are high enough to give consistent growth the full spring renovations can begin to fill the gaps and get back to good, smooth and true sward surfaces. We have already discussed spring renovation in an earlier issue - if you missed it and want to know more click here.