Dollar Spot mycelium stands out well in morning dew, it generally has very fine strands, hence the easy misidentification with spiders webs.
For the Dollar Spot trial I’ve been following this year it’s been a slow start, we didn’t get the disease showing until July which is a lot later than in previous years.
But we are now seeing disease area increasing with the more consistent warm temperatures.
What has struck me the most, going in weekly to see the developments, is just how long the dollar ‘spots’ are taking to grow out.
Unlike damage from winter Microdochium (fusarium patch) we have generally really good warm growing conditions, so I was expecting to see disease scars ‘here today gone tomorrow’.
This has not been the case, with the scars I’m watching working down the sward if conditions remain conducive.
At higher pressure the disease surface area is growing, with existing scars expanding, and new spots appearing.
At lower pressures the existing scars seem to deepen and it takes a fair few weeks at good growing conditions with low pressure to grow those scars out.
A very early stage dollar spot legion on a leaf blade, that bleached patch is wear the mycelium reached out and first touched it (with a banana in the background for scale).
When Dollar Spot activity is active and moving.
Fresh infection of previously healthy turf, it has much more of an orange/brown colour – given by the collection of many of those dark bands on the turf, like in the image above.
Older more established dollar spot scars are the ones which are almost white in colour, where the turf has died and bleached out.
It looks to start high in the turf canopy, with just the tips appearing to catch, presumably where those mycelium webs have spread out looking for new hosts.
It doesn’t look very threatening at this stage, a few whispy strands of bleached turf which looks like they will be removed at the next cut.
This is a testament to how fast dollar spot can move, and once in the host plant, even if environmental conditions improve the fungus can still move through the host as it is no longer at the mercy of the external environment.
This is what’s allowing it to keep ‘melting down’ the initial scar and deepen the dollar spot, which can lead to the playing surface smoothness being affected.
The second treatment has been made in the 2024 trial, now as we’ve seen a second wave of disease pressure at the site.
The disease area scores are averages across the 18 tee’s, so whilst 11% in the untreated area sounds not so high, that’s reflective of the worst seeing 21% disease cover and the best 4 – 5%, and the rest between.
August is considered the worst for Dollar Spot in the UK and Ireland so a good time to be on alert if you do see pressure.
It’s the consistent warm day/overnight temperatures colliding with high humidity or rain events that’s driving this.
Keep track of the Smith-kerns pressure in your Turf Advisor App to help stay ahead and give you a shot to dodge the worst the dollar spot season has to offer.
Haven’t got the Turf Advisor App? Download it for free here. (Android or iOS)
If you haven’t already curated your dashboard for Dollar Spot then some great pointers in the video below.
