November 12th

Hi All,

You get some beautiful skies this time of year don’t you ?

I snapped this shot looking across the Welland Valley in Leicestershire, absolutely cracking. A perfect tonic to unscramble my head, keep the dark dog at bay and set me up for the week ahead.

Well the mild spell continues into November and now we are approaching mid-month and only 5 weeks to the shortest day but save for some late October frosts we are untouched by winters cold grasp.

According to my weather station, we are at 18mm of rainfall for the month to date and out walking yesterday on a beautiful afternoon it was noticeable how many ditches and ponds were still dry. Now I know the west of Ireland, the U.K and Scotland have had their fair share of rainfall and The South East of late, but I fear for next year already in terms of water restrictions.

Last week I quoted lyrics from a track by The Smiths in this blog and this week it’s the title of a track by another of my ’80’s favs’ – The Housemartins that comes to mind, ‘I Smell Winter’. The song always rattles around my head when I see Unisys flagging up what I consider to be the start of winter and sitting here today a cold blast is firmly on the weather radar.

General Weather Situation

As we start the week we still have low pressure influencing our weather so that means a sunshine and showers type of Monday is on the cards for some. It’s always tricky to suggest where the showers will occur on a blog like this but looking at the V7 radar on Netweather already shows bands moving along the east and west coast of Ireland, along the A3 across the south-east of England, stretching right up into East Anglia and then a heavier rain band heading towards The Lakes. There’s also currently some heavy rain across The Borders and this will move north and east into central and north-eastern Scotland through the course of the day. Some areas may miss the showers completely but your best bet is to boot up the radar, have a look where the rain is, where it’s tracking and tackle up from there. Pleasant enough temperatures in the sunshine despite a moderate to strong south-westerly wind with 12-13°C across Wales and England, and a degree or two lower for Ireland, Scotland and The Lakes where you see more cloud cover and rain.

Overnight into Tuesday we see more showers moving across Ireland and the west coast of the U.K, some of them tracking inland across northern England. By dawn the main showers and thicker cloud base will be across northern England and Scotland but most areas will start cloudy apart from the south of England. Ireland and Wales looks similar, dry but cloudy. Through the morning those showers will dissipate and we will have a pleasant November day with moderate to strong south-westerly / westerly winds in situ. As we approach late afternoon we see that low pressure push in another heavy rain front into south-west / west Ireland and this will give a very wet Tuesday evening, particularly for the west and south-west of Ireland with some heavy rain around. Similar temperatures to Monday depending on sunshine and cloud cover you’ll either see the nice side of 13°C or the dull, wetter side of 10°C.

Into Wednesday and that heavy rain will cover Ireland and have moved into the north and west of the U.K. At present I’d say if you drew a line from The beautiful Gower diagonally up to The dull Humber, then north of that it looks like being a wet start to Wednesday, south of that it looks drier in the main. Through Wednesday morning some of that rain may push more westwards into South and Mid-Wales but south and east of this you’ll have a bright and sunny day. North of this will see plenty of rain, particularly on north-western coasts but for Central Scotland I can see that rain hanging around all day. For Ireland the heaviest rain will move through quickly in the morning but it’ll leave a showery outlook along eastern and western coasts with a drier, dull interlude across the middle of the country. Similar winds and temperatures across Ireland and the U.K dependent on cloud cover. A mild night for most areas.

Into Thursday and still we have that low pressure refusing to give up its grip on the weather. So we start pretty dry really, just a few showers across western coasts but during the morning we will see another rain band push into western Ireland. East and north of this we look dry across the U.K, if a little dull with a thick cloud base covering Wales, England and most of Scotland, save the far north and north-east where you’ll see some sunshine. So a showery and dull day for Ireland but brightening up in the afternoon from the south west. Some of those showers will push into north-west Scotland later on Thursday afternoon. The wind will swing round to the south on Thursday and that’ll usher in warmer and more humid air (more on that later) so a warmer day is on the cards with temperatures in the mid-teens down across the south of England. That temperature rise will be felt up in Scotland as well where you’ll see temperatures in the low double figures and across Ireland despite the more showery outlook. We close out Thursday with a dry theme except for the north-west of Scotland where that rain will persist.

A mild night follows and we end the week on Friday with another really pleasant day which is good because I’m off. It will be on the dull side though with plenty of cloud about but as we approach the afternoon we will see some gaps in that cloud and some nice November sunshine. Those southerly winds are still with us so that means a continuation of the mild theme with mid teen temperatures likely across England, Wales and Ireland and a couple of degrees lower for Scotland.

So what of the weekend, do we continue mild or will winter have us reaching for our buffs and thermals ?

Well Saturday looks like continuing the mild theme but we will see a shift in wind direction from mild southerlies to slightly cooler south easterlies and that’ll knock the temperature down a subtle degree or two.  Dry everywhere though. Moving into Sunday and those winds continue their shift to easterlies so straight away you’ll feel that it’s cooler than Saturday especially across eastern parts. A similar picture to Saturday with morning cloud giving way to sunnier weather from the afternoon and a dry picture for all of the U.K and Ireland, but with cooler temperatures down into high single figures / low double figures.

Weather Outlook

A pretty easy outlook to forecast for next week sitting here behind my desk with a south-easterly air stream starting off the week and then gradually shifting to a cooler easterly by Tuesday. The isobars are pretty tight though so it’ll be windy, cold in that wind, but dry for the entire week with no sign of any moisture. I reckon 7-8°C will be your lot temperature-wise, but they’ll be significant windchill, particularly on eastern coasts. When we get a run of easterlies it’s always difficult to say about cloud cover but in general we tend to push in Haar from The North Sea so that means eastern and central areas tend to be dull with western areas / Ireland seeing more of the sunshine.

Mystic Megging it…

Looking longer-term in wouldn’t surprise me if we see out November with this blocking high pressure in place and if that is the case then to my mind there would be an increasing chance of more colder air funneling in during the latter part of November (3rd week onwards) to bring night frosts and possibly even snow flurries.

Agronomic Notes

Worm Casts

Plenty around of late with the milder air and rainfall and I reckon that’s the way it’ll continue through this week however once we get to the weekend we should see activity reduce and drier conditions make those casts easier to manage from a dispersal perspective.  Not a lot we can do within the letter of the law / legislation but just flagging up that this negative should drop off as we move into next week and thereafter….

Disease pressure

With a warm, southerly, humid air stream at the end of this week I think we may see an increase in Microdochium activity.

Mild overnight temperatures and a high risk of heavy dew / guttation following this weekend’s rainfall will further increase the potential severity of Microdochium.

Running the stats through the disease prediction model I am working on faithfully with Paul in I.T, here is how it looks at present for the coming week at a U.K and Irish location.

Now the model is still in development and this week is a fine line between wind strength and dew development overnight (which will of course vary across your site depending on specific locations) but I think the highest pressure will occur from Wednesday night through to Saturday morning. Thereafter that shift in wind direction to cooler easterlies dove-tailed in with less humid, drier air will drop the disease pressure down to pretty much non-existent and that’s the way I think it’ll stay next week as well with the easterly pattern set in.  (and possibly for the rest of November)

Disease Pressure, Growth Potential and Surface Organic Matter

Looking at the growth prognosis for this week using GDD and Growth Potential we can see that in this location, (Market Harborough) we have a good growth week (for November remember) and so should see a continuation of recovery on areas affected by the summer drought.

This process will however come to an abrupt stop as we go through the weekend into next week for reasons I’ve already mentioned. You can see the GDD / G.P drop away to practically nothing in the Meteoturf graphic above next week.

Now I’ve talked a lot about disease activity of late and the two sides of the mild autumn weather coin but I got sent a great picture this morning (cheers Rob) that really highlights both sides of that coin in one image.

This picture shows some disease scars from the early / mid-October activity peak that we experienced this autumn. You can see that the scars are already well on their way to recovering and I’ve calculated that this recovery process has taken approximately 86 cumulative GDD or 8.3 cumulative Growth Potential since the main damage occurred to the sward.

So first off there’s the two sides to the mild autumn coin, disease scarring but also recovery.

No great shakes you may say but there’s another factor a play here and that’s surface organic matter. The image above is taken from a golf green with low surface organic matter in the top 0-20 / 0-25mm and that is instrumental in my view to fast recovery.

Higher surface organic matter means deeper scar formation and also the potential for a higher latent disease population in terms of spore numbers / mycelium. So on greens with high surface organic matter (let’s say > 7.0% in the top 0-25mm to give you a benchmark) you not only get deeper scarring when you get a disease outbreak but you may also have a higher potential for reoccurring disease through the following autumn / winter / spring.

I’ve used the image below before but I think it tells a good story.

It highlights the life cycle of a disease scar from initiation in late October 2016 through to the following spring and this image comes from a green with high surface organic matter content.

Now of course as we go into winter proper we will face a scenario with new activity around pre-existing scars and with no Iprodione curative to fall back on there will be little we can do in these instances to halt the progress of the disease. So that’s why not only should we be working to minimise the level of disease through the autumn (and yes I fully appreciate it is a tricky process) but by reducing the surface organic matter content at the same time (by good aeration / cultural practices) we get a win-win result.

Are monocultures natural ?

I’ll finish off this blog still on the disease theme but broadening it out to look at grass species.

The image above was taken awhile back from a golf course originally sown down with Creeping Bentgrass but now colonised to a lesser / greater extent with Poa annua as well. So the greens are a mixture of Bent / Poa and the effect of having a mixture of grass species is clear to see. The disease in the image above is only apparent in the Poa part of the sward, the bentgrass is unaffected and by having a mixture of species present the sward has better resilience to disease.

The term sustainability is banded around a lot in our profession but I prefer to use the term ‘resilience’. Resilience in the face of two of our biggest challenges, climate and legislation.

It’s quite simple, having a mixture of grass species in a sward provides greater resilience to abiotic and biotic stress factors whereas trying to maintain / create a monosward sets your path firmly against nature.

Monoswards do not occur naturally and so to preserve / create a monosward you need to make greater inputs, be that nutrient, pesticide, sand, wetting agent, maintenance / cultural practices.Every grass species has ‘baggage’ and we have to weigh up the pros and cons of this baggage before we make a decision on the type of sward we want to try and create / influence.It is a connected system because in order to try and introduce a grass species into your sward you must have surface organic matter under control. Seed / soil contact is key to overseeding success so that’s another box ticked alongside reduced surface organic matter and its benefits. Looking objectively, I think our objective should be diversity of grass species within a sward to mitigate the effects of increased disease pressure.

Ok I’ll hop off my soapbox for this week.

All the best for the coming week, enjoy the milder temperatures (for some) because in a week or two you’ll be looking back at them with envy 🙂

Mark Hunt