After a warm and humid week last week, punctuated by some lovely autumnal sunshine and thick grey cloud cover, thick enough to bring us 4mm in a downpour that caught me on the way out for a curry on Saturday night, but courtesy of Meteoblue’s RainNow, I had a brolly !
We have a continuation of September’s nice start with high pressure in charge again this week but the weather will be subtly different and hopefully that will be good news for disease management.
General Weather Situation
Well a pretty easy forecast this because of the stable high pressure situation with a dry week in prospect for all of the U.K and Ireland, but as hinted above it will be different and this difference relates to the wind direction and also cloud cover. What you’ll notice this week is that the night time temperatures will be much lower than last week (with the exception of last night which was well parky) and that means that disease pressure will be lower for sure.
The best sunshine of the week should be reserved for the first part of the week, but it’ll depend where you located because it’s likely that we’ll see greater cloud cover in the north, over Scotland, but particularly along the eastern coastline of the U.K. and that’ll peg back temperatures considerably.
So in the warmer sunshine, you can expect temperatures to push up into the low twenties, but under cloud cover, it’ll be more like mid-teens. Night time temperatures will be lower under clear skies, so I’d expect single figures here, maybe dropping down enough to give a grass frost, particularly at higher elevations and in Scotland. Nothing unusual here, I can remember fishing the River Dulnain in Speyside as a wee slip of a lad on the last day of August and there was a good frost 🙂
Winds will be light and mainly north-easterly / easterly and that’s why cloud cover will come into play, particularly at the back end of the week because it’ll pull cloud off The North Sea. So the east / south-east may well end up running cooler than the west because of the ever-present threat of cloud cover.
Weekend-wise it looks more of the same, but with a higher risk of cloud coming into play, so staying dry, but perhaps cooler over a wider area because of the more widespread cloud cover.
At this stage it looks like we will remain under the influence of high pressure next week but it’s getting squeezed by some pretty deep low pressures so I can see it eventually moving off towards the end of next week and low pressure coming back into play in the shape of strong winds and rain. That said, it looked the same last week, but the high strengthened and maintained the status quo, however I think the odds on it staying in situ for the whole month are pretty low.
In fact we saw the opposite because with that high pressure came some very mild, muggy humid nights with mid-teen night temperatures and this meant that conditions were in fact ideal for fungal development, so go to the back of the class Mr Hunt on that one 🙁
As well as the ongoing situation with Anthracnose, which I covered in detail last week, I also received numerous reports of active Fairy Ring and Thatch Collapse, along with Fusarium and even some Dollar Spot on tee areas. It’s enough to make you weep sometimes, but lets be pragmatic, this is the rub, this is our industry, we just need to knuckle down and sort it 🙂
Fairy Ring and Thatch Collapse has been significant this year and most of this is down to the weather for sure, however if you suffer from these, take a look at where they are occurring on your surfaces and try to determine if there’s a pattern both in terms of the surfaces it’s affecting and the specific areas. This should be your mindset with all diseases, i.e “Why is it occurring where it’s occurring?” With Anthracnose for instance I have seen two distinct patterns, the first related to stressed areas, wear pathways across a green for instance and here the Foliar Blight has been the most active form of the disease. Conversely on non-stress areas, lower parts of greens for example where moisture levels are high then here I’ve seen Anthracnose Basal Rot, rather than the Foliar Blight.
With the latter you need to look at where it’s ocurring and then plan accordingly to try and remove the background issue, be it sub-surface drainage, organic matter content, etc
For sure greens with a high organic matter content will be more susceptible to most diseases, but particularly Microdochium nivale, Superficial Fairy Ring and Thatch Collapse to name but a few.
With Thatch Collapse, you should look at the affected areas and gently press down on the patches. If there’s a clear depression in the surface, deep enough to affect ball roll, well then you have too much surface fibre whatever you think and if your club is one of those that doesn’t like you aerating and topdressing, then now is the time to use this disease activity as a lever. Take some photos, explain why it’s occurring and what needs to be done to combat it and explain that if preventative / curative aeration isn’t undertaken, then all 18 greens will be like this. No one in their right mind will want this and hopefully sense will prevail 🙂
Once you have Thatch Collapse then it’s just a case of aerating (trying to avoid heaving in the affected areas is sometimes difficult I’d accept) , topdressing to try and maintain levels and let it run its course. For sure you can blat it with Azoxystrobin, but you are only dealing with the symptom, rather than the cause.
Microdochium nivale pressure
As we enter the start of the main disease preiod for most, I’m going to try and predict (better than last week) when we’re likely to have the highest activity from this pathogen. Looking at this week we have a dry scenario so that’s good in terms of discouraging disease, we will also be cool at night, another plus point. On the negative side, we will have some heavy dews if your night time coincides with clear skies, so that’ll increase leaf wetness and encourage disease activity. In balance I’d expect any Microdochium that’s already present to bubble away, not becoming too aggressive, but it’ll be there in the background, particularly on shaded areas that don’t get the chance to dry out during the day. I was out on a blat on my motorbike at the weekend and noticed the areas under trees were staying damp all day despite the warmth so a tad tricky. An indication that on sportsturf surfaces in shade, the plant leaf will be staying wet for long periods of the day now that the sun is sitting lower in the sky. So disease pressure will be higher on shaded areas this week, so that’s the area to keep an eye out on.
If you’re clean at the moment, then I’d expect you to remain so and as I intimated last week, try to keep your powder dry with your systemic + contact mix for as long as you can this month, it’ll pay dividends later in the year.
GDD & Growth Potential Outlook
The cooler nights this week will start to drop soil temperature and also GDD / GP figures. I just programmed in my anticipated day and night temperatures for this week into our spreadsheet and it gives a predicted G.P range from 0.6 dropping down to 0.4, in other words growth will be slowing down and so that means outfield areas should come nicely under control, but also fine turf will start to need a bit of a helping hand in the form a light foliar tonics to maintain health and density.
Lot’s of people reporting high levels of casting worms on turf surfaces last week, specifically because of the end of August moisture and the heat, however these too should be starting to decrease as the top surface dries out and the worms move deeper. (Expect them to reoccur when the rains arrive)
I’ve had a few reports of pecking, Leather jacket and Chafers doing the rounds, the former seem to have had a mid-summer egg laying spell in order for their grubs to be active now. I find it quite difficult to keep up with quite where we are life cycle-wise with Leatherjackets but it figures as I had pictures sent to me of mature Crane Flies back in the spring.
Ok that’s all for this week, enjoy the sun if you get it up or down your way, I love autumn sunshine and the colours that come with it, I know it means winter is next up, but that’s the rub…
All the best…