March 11th

 

Hi All,

Out walking on Saturday against a gale force wind, I could not help thinking the hedgerows and fields still carried a tinge of winter and seem slow to embrace the spring.  Hardly surprising when day time temperatures struggle into the high single figures and a pronounced windchill comes into play. 11 days into March and we are beginning to lose the advantage we gained in our warmest February with inconsistent and slow growth rates a reality on our turf surfaces. (unless you have applied 40% of your entire N for the year that is :))

There are (maybe) fleeting signs of a warmer air stream but these are still over a week away as it stands now. If this does come to pass it still means 60% of the month will have passed by with cooler than normal conditions. February and March – a role reversal and another reason why the calendar is no longer a good guide. That said, one of my over-wintering Hedgepigs decided to come out of hibernation late last week, that’s 2 weeks earlier than expected and boy is he / she a hungry Hedgehog ! Lovely to see though.

Ok onto the weather for the coming week because Tempus fugit my friends…:)

Image courtesy of meteocentre.com

General Weather Situation

As you can see from the GFS output above we are currently stuck in a trough pattern in the jet stream into which successive Atlantic low pressure systems deposit themselves and pull in unsettled, cool and wet weather and strong westerly winds. By and large this is our pattern for the week though it will occasionally tip on its side to pull north-westerlies in and chill down the temperatures a tad so let’s put some detail on it.

Monday dawns bright and cold as I look out of my office window and that’s the way we look to stay for most of the day for the U.K and Ireland with cloud building from the west this afternoon. So a nice dry but cold start to the week after a soggy weekend for many. Late afternoon we see a heavy rain front push into the west of Ireland make haste eastwards into Scotland, the north-west of England, West Wales and The South West later tonight. Here it may initially fall as wintry showers over elevation. By the wee hours of Tuesday it has cleared Ireland and is covering all of the U.K, with some heavy rain and snow (for elevation in Scotland and northern England). A cool day with temperatures ranging from 8-10°C and a strong, westerly wind decreasing as the day goes on a little before strengthening again overnight.

Tuesday sees that rain and wintry shower mix over all of the U.K with maybe only the east of Scotland and north-east of England missing the worst of it. Ireland looks to start cloudy and dry with scattered sunshine but still with a chance of wintry showers over The Wicklow mountains. Through the morning that heavier rain sinks south into The Midlands and central England, Wales, intensifying as it does so, whilst the north-west and west of Scotland still sees a mix of wintry showers and rain. By the afternoon we see a new rain front pushing across western Ireland and the heaviest rain in the U.K south of a line from The Severn to The Wash. North and east of this you’ll see sunshine after the rain, more so in central and eastern counties of the England and Scotland, whilst Ireland will see a west-east divide when it comes to the rain / wintry showers mix. By dusk, one rain front is departing into The Channel, the next is pitching up across the western coastline of the U.K and again falling as wintry showers over elevation and maybe down to lower levels across South Wales into Tuesday night. For Ireland the rain will centralise through Tuesday evening with maybe just the south of Munster / Leinster missing the worst of it. Really windy overnight again with gales and very strong winds first off on Tuesday and these winds will peg the temperatures back to mid-single figures for everyone, allied to a strong windchill.

Wednesday sees that wind turn north-westerly and that’ll push a raft of rain, hail and wintry showers down from the north-west of the U.K across The Midlands and into Central England and across the north-west of Ireland. They’ll still also be a threat of a Christmas Pudding scenario on the Sugarloaf to boot. Through the morning these showers will become more confined to the north and north-western regions with sunshine breaking through. Still the risk of blustery showers, a four seasons in one day scenario if you’re out and about. Really, really windy again from the off on Wednesday with gales and strong gusts of wind making life tricky. The wind will gradually weaken as we go through the 2nd half of the day. Temperature-wise, a bit milder on Wednesday with temperatures up into double figures in that gusty wind so there is a slight up side 🙂

Overnight into Thursday and the seemingly relentless raft of wind and rain kicks in again with a heavy rain front pushing into the north and west of Ireland in the early hours and soon pushing across The Irish Sea into Scotland, the north-west of England, Wales and The South West. By dawn it’ll have spread down to most areas of the U.K and Ireland so a wet start to Thursday mornings rush hour. So again a pretty wet day on Thursday with heavy rain across Ireland, the west and north-west and some central areas. Later in the afternoon they’ll be some breaks in the rain across the east of England and this will be followed by brighter weather pushing into the west at dusk. Again a very windy day with gales and strong gusts of wind from the north west from the off. The only plus side will be that the temperatures will stay up in double figures through the day and actually through the night.

Closing out a wet and blooming windy week, Friday sees a re-run of Thursday with rain crossing Ireland in the early hours before pushing into the west of England, Wales and Scotland in time for the morning rush hour.  This rain will quickly clear Ireland and the west as it goes, maybe lingering over elevation in the north and west but some longer spells of sunshine in-between blustery showers are likely going through the day. We should end up with a nice and sunny picture across most of the U.K and Ireland, maybe still with some wintry showers across the north and west though. Temperatures stay up in the low double figures in that sunshine and strong north westerly / westerly wind, though maybe a little quieter than earlier in the week.

No surprise then that the outlook for the weekend continues unsettled with a trough system and low pressure dominating the weather dynamic. The plus point will be a dropping wind strength through the weekend though I’d suggest a sunshine and blustery wintry showers scenario is likely for Saturday and Sunday. No point me putting anymore detail on the rain than that because you’ll see closer to the weekend where and when it’ll fall. The wind is also likely to swing northwards through the 2nd part of Saturday and that’ll make things cooler with a risk of frost of Sunday morning perhaps. Of the two days, Saturday looks the most unsettled so a nice early start for a walk on Sunday in a crisp frost on non-thawed fields could be just what the mind and soul requires 🙂

Weather Outlook

Image courtesy of meteocentre.com

So here’s how we look to start next week and if you look at the GFS gif at the start of the blog there is a subtle difference with the demarcation line of cold air lifting higher. That’ll hopefully allow milder air from the Atlantic high pressure to introduce a milder air stream into our weather mix from the start of next week.  So next week looks like starting unsettled with a milder, westerly wind and rain across the U.K and Ireland through Monday and Tuesday. As that high starts to exert its influence, the unsettled weather will lift up so we will see less rain in the south and across central areas and it become more bias to the north and west through the week. I think towards the end of next week we will see the winds drop and maybe more in the way of sunshine but with a risk of night frost. This will continue through the weekend before a new low pressure system whips in from The Atlantic.

Agronomic Notes

So after a great February, things have kind of ground to a bit of a halt wise when it comes to growth unless of course you’ve shoved 40kg / ha of N on in one go 🙂

Looking at last week and then the prognosis for this week on Meteoturf, we aren’t exactly tearing the trees down growth-wise…

So a rip-roaring 6 cumulative GDD (0.8 cumulative G.P) in this week’s forecast isn’t that great and to put it in perspective, when we have a really good March from a growing perspective I’d expect to see something like 28 cumulative GDD (2.8 cumulative G.P).

This time last year we were staring down the barrel of a late Sudden Stratospheric Warming event and a very cold, wet spring but actually the prognosis for the same week in 2018 from a cumulative GDD perspective was around 8.5, here in Market Harborough, so we are similar or even a tad colder than the same week in 2018 unfortunately.

Looking at our Thame location, we can see that the cumulative GDD to date is now well behind 2017, but still ahead of 2018, courtesy of a much warmer February.

2019 GDD are projected till 18/03/19

So what does this mean in the real world ?

Well it means growth will be on the slow side this week, nothing dramatic I am afraid if you are looking for recovery from aeration and / or disease scars. The loss of wind later in the week and the return of cold nights will grind us to a zero scenario from a GDD / G.P perspective.

That said I’m hopeful if the weather plays out properly thereafter that we should see a pick up in that milder westerly air stream. Kind of a funny one really because if you looked at March in isolation you’d say it was bloody cold and the spring is late but because we had such a warm end to February, the mindset is still somewhere in-between I think.

Nutrition-wise it means sticking to a granular scenario for the time-being if you want / need a turf response (not that you’d be able to spray too much currently judging by the wind strength looking out of my office window !)

Low temperature-available nitrogen is the name of the game so that means ammonium sulphate, potassium nitrate and / or ammonium nitrate-biased formulations and of course at a time of year when you may or may not want to knock back moss, having some iron input as well will do no harm.

Bit of disease activity doing the rounds last week..

There were a couple of occasions last week when the wind dropped and the temperature / humidity dynamic increased enough for it to push on activity on existing scars.

Looking at my Netatmo readings, the worst nights were the 6th and 9th of March for my location.

You can see the scenario below ;

So reasonably mild overnight temperatures and a wet grass leaf for long enough for mycelium activity. In my experience this was principally confined to existing disease scars where a high population of mycelium / spores are already present.

So looking at some scarring on greens, this sort of dynamic is going on…(2016/17 scenario shown below)

When we do eventually get that uplift sometime in March / April we will see a final resurgence of disease before (hopefully) the growth rate of the grass out-strips the pathogen and healing takes place. It’s a potent reminder though that if you are / were unlucky enough to get caught with heavy disease scarring in mid-October, it is realistic to still be looking at scarring 6 months later, particularly of course if your greens are Poa dominated (like most).

What are the learns of 2018 / 19 from a disease perspective ?

Well there are many in my mind and some of those learns generate questions that currently I am unable to answer…Using my disease prediction model (under development), you can see how the disease severity panned out over the autumn / winter for a golf club in Kent…

So the first real peak of activity was at the end of August but at that time grass growth was strong so this may only have shown as some copper blotches which soon grew out.

The next significant peak which caused scarring for many was mid-October (3rd year on a bounce that it has occurred at that time) and then we saw the highest disease pressure in December courtesy of that Atlantic high pressure system pushing up mild, humid air. The highest disease spike of the whole season occurred on Christmas Eve as we experienced mild day and night temperatures, 100% humidity, no wind and 24-hour plant leaf wetness due to the air temperature and dew point being equal all through the day and night. Thereafter the spikes have been of lower magnitude and really correlate with activity around existing scars only.

So you can see why some people got to Christmas week, maybe breathing a premature sigh of relief at reasonably clean greens, but with the wet and windy weather run up didn’t manage to get a preventative down. And then got nailed.

Even amongst those end-users that did get a preventative down, some still saw aggressive activity maybe because uptake was slow or just that the balance tipped so comprehensively towards pathogen development ?

We know there’s always the dynamic between the rate of pathogen population growth vs. the rate of control of the fungicide. Sometimes the climatic conditions tip very much in favour of the pathogen and even with high A.I-loaded products (like Instrata for example), we still see disease development.

Leap frog ahead to autumn 2020 when we no longer have these products available and have maybe 4-5 systemics labelled for use on Microdochium, (some of which are stronger than others) life will get even more entertaining from a disease control perspective.

So it is obvious then that we have to work harder at controlling the other factors that influence disease other than fungicide applications. But what are they ?

Grass Species…

Well first and foremost is grass species in my mind, that is working to introduce a mix of grass species to your surface and not having all your eggs in one basket. We have seen some interesting debate on Twitter recently about the use of ryegrass cultivars (tolerant to close mowing) on fine turf. Now for many that would leave a bad taste in the mouth and if Jim Arthur was still alive, a vitriolic response I’m sure. Just to be clear here, I had the dubious honour of debating with Jim many years ago during a talk I was giving at Sparsholt College (thanks for that one Jeff :). We had an animated and interesting debate, after which we sat down and had lunch together, I liked him. I may not have agreed with everything he said or wrote, but I did respect him.

I was chatting to a good customer / friend recently who has been over-sowing rye on his heavily-played greens for many years than he cares to remember. He cuts them low, he has lower than average disease pressure and it doesn’t build fibre. For him, his club and his punters, it works.

OK for some a step too far and I understand that totally, but above all things in the next few interesting years, we must keep an open mind.

Whatever grass species floats your boat we have the interesting issue of establishment and the oft-quoted comment “I see lovely lines and then nothing…”

Here quite clearly the enemy is surface organic matter (S.O.M) and rather than talk %, I’ll talk thatch structure. If your S.O.M is compact in nature, that is to say if you try to push a knife in sideways, it is heavily resistant to this process, then you are up against it. If you see mainly lateral rooting in the turf sample (sideways rooting) then the nature of the S.O.M is such that existing grass cannot physically develop a root downwards, so what chance would we give newly-introduced grass seedling ?

The answer is obviously to incorporate enough topdressing through the S.O.M so it is not compact and the plant can root easily down through the surface into the rootzone below. You can of course achieve the same result by hollow coring, i.e removing a plug of S.O.M and filling it with sand and then seed. The new seedling sits just under the cutting height (so has more chance of survival) and no impediment to new root growth.

So maybe rather than just thinking about overseeding, look at what you are overseeding into and do the preparation beforehand in order to gain a good result ?

I’ll cover some of the other factors in my preceding blogs but I note that the 1 p.m. deadline is fast approaching and my Inbox is filling up (again).

All the best this windy week, take care when driving or when you are out and about on your facility for falling branches and trees.

Mark Hunt

 

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