I've been asked a few times this month for best practice advice for Dollar spot.
To start with I've put together a basic Dollar Spot FAQ to go over the symptoms and drivers.
Establish the risk
- Have you seen it on your site before?
- Are you fescue dominant?
- Are you in a mild area of the country?
- Do you see high humidity?
If the answer to those questions is yes then next we should......
Establish your tolerance level
As with most turf challenges now we need to be ahead of the game and establishing what we're prepared to tolerate. We can then put plans in place to avoid the problem.
If you are prepared to tolerate some Dollar Spot and your in an area that doesn't see high humidity and you don't have Fescue dominant swards then you'll probably be absolutely fine by delivering all of the cultural controls listed in the Dollar Spot FAQ blog.
- Remove dew
- Increase nutrition
- Overseed with resistant cultivars
- Control thatch
If that alone doesn't offer enough then integration of Hicure and Ryder into your programme during this summer period will help relieve stress and keep the plant healthy enough to withstand a little more pressure.
However, the high pressure sites, with high fescue content and high humidity are at certainly at risk - and this pretty much sums up Devon and Cornwall.
Low tolerance + high risk = Instrata Elite
Instrata Elite is great on Dollar spot but you'll probably need to build a programme, Look to the commencement of pressure and the Smith-Kerns model is great for that Spreadsheet link here....
The model recommends a first preventative application at 20% pressure threshold and then every 28 days (although I'd bring that in to 21 days if zero tolerance is your true objective) when in sustained pressure.
Instrata Elite will need additional support from our competitors so look to the labels and talk to your supplier about good programmes, put a plan together and watch the model. Once the pressure period commences then implement your programme on a 21 day interval until you're confident that the humidity and / or temperature has subsided later in the year.
Knowing that the past 3 weeks we have had very high temperatures and now we are in a sustained period of rain I'd be thinking about that first application when weather conditions allow.