Dollar spot is something that’s not been a big problem in the UK & Ireland historically, but its already serious in France and Germany.
Last year we had a really long Dollar spot season with active flareups all the way into November.
That’s a 6 month window when we consider June can bring the first cases if the weather plays out a certain way.
It’s from now where sites who have had pressure before should be on guard.
It’s not strictly driven by dates in the calendar as we know, you can see Dollar spot in May if conditions allow, but its more likely to begin in June.
If it was a recipe, then some sites will already have one of the two main ingredients: Temperature.
Dollar spot needs a certain level of temperature to develop, 15°C is generally considered a starting base.
You may see Dollar spot under this threshold, but its less likely and would need to be very moist indeed.
Leaf moisture is the other main ingredient. Be that in the form of rain or irrigation, anything that leads to the humidity in grass canopy raising can increase the risk of Dollar spot (if the temperatures are in the zone also).
As Dollar spot is our disease focus this year at Syngenta I’m putting together some user trials to track how it develops this season, one in the East and two in the South of England. (Let me know if you’d be interested in being involved in future user trials).
The premise will be simple, monitor the Dollar spot pressure using the new Syngenta weather app (still in BETA testing – this will help me road test it also).
Apply a fungicide when pressure is above the threshold, Smith-Kerns would suggest 20% but I’ll discuss this with the sites involved to set a value which reflects the base pressure they see.
If you’ve got the app you can ‘play along’ over the season and see where your Dollar spot pressure is coming in.
Just set up the Dollar spot ‘module’ as shown above, mine is set for near Cardiff so already shown a little pressure this month.
It looks to be a great tool to help monitor Dollar spot pressure, so I’m excited to get into it this season and feed back how the trials are going once they kick off.
For more about Dollar Spot, take a listen to the April 2023 edition of On The Horizon where Glenn and Henry talk about it in some detail.
