November 30th

Hi All,

After a truly grotty weekend with clouds to the ground, perpetual dew and fog and very little wind (except when I went fishing of course on Saturday for my last fly fishing outing of the year booh hoo), it is going to be nice to see the back of it. November is the new October when it comes to disease pressure I’d say judging by this years experience with a lot of clubs struggling to hold back Microdochium nivale and late Anthracnose. And of course we now come out of lockdown and in the case of Leicestershire (Tier 3), we jump straight into a more stringent one with travel restrictions impacting on most of my past times as our neighbouring counties are Tier 2.  So it’s away with the fishing rods for awhile and on with the walking boots / running shoes 🙂

Image courtesy of New Scientist

Of course we now have some light at the end of the tunnel with multiple vaccines on the horizon. Reading an article in New Scientist on the challenge of world vaccination, it is truly immense, things you just don’t think about. For instance, manufacturing the vials that vaccines are stored in requires a special type of glass and that represents a bottleneck in supply that is now being addressed.  Vaccines can be shipped by air though it would require 8000 Jumbo Jets to shift all the vaccine required worldwide, but syringes go by sea and land so there’s an effort currently to get enough syringes out to where they’ll be required before the vaccine(s) appear(s).

I only hope our current government puts in place a better organisational system than they have done to control the spread of the virus when it comes to vaccination and logistics.

Time will tell but let’s hope we may return to some form of ‘normality’ from Easter 🙂

Onto the the more mundane subject of the weather and the week ahead as we are now only 3 weeks away from the shortest day 🙂

General Weather Situation

So we start a dreary Monday with a band of rain straddled across north west Ireland, Scotland and England. Through the morning this rain will slowly move south and east across most areas clearing Scotland as it does so to leave behind some brighter and fresher weather in return. This rain will move across Ireland and England and it looks to be more concentrated along the east coast of England down to the south east later in the day. That rain over the east of Ireland will push across The Irish Sea into Wales later this afternoon to give a soggy end to the day there. A mild day, double figures in Scotland early doors before dropping a few degrees as the cooler, brighter weather pushes in. 8-9°C across Ireland, England and Wales and dull with it for the most part, clearing from the north. Through the day we see the return of some wind, initially from the west but swinging round and strengthening from the north later.

Onto Tuesday and overnight we see the leading edge of high pressure influence our weather. This means a northerly wind, so feeling cooler and brighter across the west and central areas. Scotland, the east coast of England and Ireland though looks to remain on the dull side I’m afraid and here temperatures will hold up higher. A dry day everywhere, which is nice (ala The Fast Show). Through the afternoon the temperatures will drop away, skies may clear and a frost sets in. 8-10°C  across Scotland and Ireland but only 5-8°C  for England and Wales with that northerly wind pegging back temperatures.

Mid-week beckons, my how time flies when you are enjoying yourself. So Wednesday sees the leading edge of a cool, Atlantic low pressure push rain into the north / south west of Scotland and the north west of England. Through the morning this rain will move down the north west coast of the U.K and into North Wales, lessening in intensity as it does so. Elsewhere over Ireland, the east of Scotland, most of England and Wales, it’ll be a dry morning but again with plenty of cloud around. The wind will be light initially but will begin to pick up during the second half of the day. The rain stays mainly across the north west of Scotland and it’ll turn wintry over elevation there. So aside from the north west, Wednesday brings another dry, dull day with a few breaks in the cloud after the initial rain down the north west of England has pushed through. Temperature-wise, similar to Tuesday with 6-9°C doing the rounds.

Onto Thursday and overnight that Atlantic low pressure system has pushed rain further south across Ireland and the west coast of the U.K from Scotland down to The South West. As we progress through the morning that rain pushes eastwards and over elevation across The Highlands and Pennines will fall as a mix of wintry showers and hail. So the eastern side of the U.K will start dry with some brightness on Thursday but that rain is moving east and expected across central and eastern parts by lunchtime. So most areas will see rain on Thursday with that rain clearing Ireland from the west and Scotland from the north through the course of the afternoon. Despite a strong to moderate southerly wind for England and Wales, it’ll remain on the cool side with similar temperatures to Wednesday. Cool enough then for some wintry showers over elevation across Scotland.

So over the course of a few days we move from peak pattern with centralised high pressure to a cold, wet and wintry trough pattern  as you can see from the GFS output above. Overnight the centre of the low pressure has sunk into The Channel and there it’ll stay for more than a few days so that means the southern half of the U.K will pick up a higher % of the rain with some heavy rain overnight along the south coast and up to The Midlands.

So Friday looks a tricky one to forecast because a lot depends on exactly where the low pressure ends up centred. At this stage it looks like the southern half of England and Wales will pick up the bulk of the rain but exactly where it is going to fall heaviest is tricky to say. Ireland should have a mainly dry day but as I mentioned above it does depend on where that low ends up so the east coast could pick up rain if it drifts westwards. So a day of sunshine and showers with some heavy rain mixed in. The low pressure pulls more rain into the east and north east of Scotland during Friday and some of that rain will again turn wintry over elevation. That rain intensifies over the 2nd half of the day across the south of England and Wales with some torrential stuff about. The same also for the north of England and possibly The North East. With the low now south of the U.K, it’ll pull in easterly and northerly winds so that means a pretty bitter feeling day with temperatures in the 4-6°C  region. You’ll also note how tightly-packed the isobars are so Friday and the weekend in general looks to be very, very windy with gales in places.

So as hinted above an unsettled weekend with plenty of rain around, very windy and feeling pretty cold. Not selling it to you ?

So Saturday is another sunshine and showers jobbie, cold and windy with it as well. Again it’s a bit of a lottery where and when will get rain but initially it’ll be more east coast-biased moving across central areas and finishing with the west coast of the U.K later. Ireland could again stay largely dry but it’ll be very windy with a pronounced north wind in situ here. For the southern half of the U.K, it’ll mean more in the way of showers but the wind will begin to die down through the 2nd half of the day. Scotland will still see a mix of rain and wintry showers affecting the north east of the country and moving west and south through the day. Remaining cool with 4-6°C likely but then it is December. A slightly better day on Sunday with less in the way of rain around but there still will be some blustery showers doing the rounds. Ireland will see showers pushing south from the north west through the day, urged on by a strong north westerly wind. Again tricky to say where the worst of the rain will be but initially it looks like being across the north east of England / Scotland pushing westwards into more central areas through the day. Less rain around though on Sunday so you could end up with a dry one and even see a glimpse of winter sunshine. Remaining cold despite the wind swinging round to a more south westerly aspect with 4-6°C again likely.

Weather Outlook

So as you can see from the above GFS projection we look to start the next week on the cold side with night frosts and a cold northerly wind in situ. As so often happens when we are sitting in a trough pattern, as one low pressure exits stage right, another one is projected to enter stage left from Tuesday. So a slight change during Tuesday as the west picks up some milder air but not for long as the low is projected to be in place by mid-week bringing cooler and unsettled conditions. Again it looks to me like the southern half of the U.K will pick up the worst of the rainfall from Wednesday onwards. Now again it is tricky to say but with cold air sitting over us we could see some wintry showers continue next week across Scotland and the north east. It looks like the worst of the rain will be into Ireland on Tuesday and across the southern half of Ireland and England on Wednesday. Thereafter we will move back into a more northerly air stream, still with wintry showers affecting the north east / west coastline of the U.K and continuing to feel on the cool side. So remaining cool and unsettled next week with some night frosts. There is a suggestion after that we will pull in some slightly milder air towards the middle of the month but remaining on the cool side and unsettled through December.

Agronomic Notes

Well with a weekend of zero wind (except temporarily on Saturday here), similar day and night temperatures and close to 100% humidity, it is no surprise that we have endured really high disease pressure and some very aggressive outbreaks courtesy of Microdochium nivale.

Here’s a pic for you…

So this green was the only one that didn’t get sprayed 4 days ago with a fungicide + hardener mix (I’m not mentioning brands) and as you can see it got absolutely clattered with Microdochium. Just looking on social media, there are many similar images, end-users bemoaning the lack of efficacy of modern day fungicides and the like and others saying that it is to be expected. Well firstly I feel your pain, it’s never good to come into work and see greens looking like this. It is inevitable that we will see more disease on greens nowadays than we use to because yes the fungicides are applying less A.I per hectare, yes the climate is throwing us some curve balls in terms of dew formation / humidity / overnight temperatures and the like and yes we have a host grass species that is more susceptible to this type of disease more than ever.

So in some respects we will have to get used to it, for others it may act as a catalyst to try and improve areas of their particular IPM program that they feel might be lacking. That said I know people that have all the right IPM points in place and have suffered aggressive disease outbreaks. So we have to appreciate (but not like for sure) that the cards are stacked very much in favour of the pathogen and less in favour of our particular IPM program at certain times of the year. 100% it is pretty crap timing when here in England we are due to come out of lockdown and golfers will return to golf courses later this week.

So why was the last few days such a shocker ?

So here’s the weekend weather conditions in my favourite part of Essex but for once I could have use the same data for just about anywhere in England, Wales, the southern part of Scotland and of course Ireland.

Across many areas we had the same basic conditions, high humidity, re-forming dew and no wind to dry down the leaf. Dove-tail that in with a day and night temperature that stayed between 5-10°C day and night and you have a recipe for high disease pressure.

The chart above shows that even if you were removing dew at 7 a.m. every morning, it would have reformed again on the 27th, the 28th for a short while and then on the 29th and 30th as well. Over the 29th and 30th of November, we saw 30+ hours of constant wet leafness with air temperatures hovering between 6.5 and 8.5°C. Looking at the growth of Microdochium nivale in response to temperature, we know from our own research that at 7.5°C  it is still capable of growing at 50% of its maximum rate, so the temperature was there no problem. The plant leaf wetness was also there and importantly for fungal growth, it was present for continuous hours, as fungal mycelium are sensitive to desiccation as they develop on the surface of the grass leaf.

These conditions led to a number of different types of disease development.

1. New infection sites in the sward that weren’t apparent prior to the weekend.

2. Re-activity around existing disease scars shown as a dark halo and water soaking.

3. Re-activity around existing disease scars with the development of aerial mycelium and spores.

You can see all of these in the image above.

If you look closely at the patches with mycelium under a microscope, you’d see this…

Image courtesy of Kate Entwistle – The Turf Disease Centre

If you look closely at this cracking image of Microdochium nivale developing on the grass plant leaf you can see the aerial mycelium and some brown structures on the surface of the leaf. These are called Sporodochia and contain the familiar bow-shaped spores of Microdochium nivale. There are millions of spores in each Sporodochia. So once you see aerial mycelium you know that the disease has been through it’s whole life cycle and has produced spores and aerial mycelium that will allow it to infect neighbouring plants by way of movement through water and air.

It isn’t all gloom and doom and for every bad image I’ve also had some positive feedback with a number showing areas under a pesticidal and non-pesticidal control combination relatively clear of disease. The image above (cheers George) is one such example. It gives a very clear indication at just how strong the disease pressure has been over the last 5 days when you see the size of the patches on the untreated areas and the amount of mycelium being produced.

Looking ahead…

With the development of cold low pressure systems coming into the weather picture from today (and I note the barometer is falling slowly as we speak), air temperature will fall and critically we will start to pick up wind strength which as we know not only restricts fungal mycelium development but also the formation of dew on the plant leaf. Even wet and windy weather will feature rapid dry down of the plant leaf between rain showers  and this will make it very difficult for the fungus to continue development.

So above is a schematic of disease pressure over the past 5 days from one location and you can see the successive days of 70% + pressure. Hopefully you can also see the disease pressure dropping away through the 30th of November as the temperature drops and wind strength increases. So the good news is the hump is over and life will get a bit easier thereafter. If you have fungicide cover on and it has been struggling to control the disease then it is likely to kick back in as the balance tips away from the disease.

Of course we are also welcoming back golf (In England) and that means wear and tear just at a time when we could probably do without it from a recovery perspective. The change to wet, windy and cold weather means for me that granular nutrition will be more effective than liquid going forward so I’d be looking to start the process of growing disease out with a light rate of low-temperature available granular fertiliser.

Till next week, all the best..

Mark Hunt