Monthly Archives: October 2018

October 29th

 

Hi All,

Firstly an apology for the late publishing of the blog over the last few weeks. Apparently it’s being done on a different platform now with a different ‘support team’ who clearly can’t tell the time. I don’t think it’s acceptable to email you guys at 7p.m. in the evening so please accept my apologies for this. We are working on a better solution.

Ok, onto the weather and it is quite a change from the usual weather pattern for this time of year with an absolutely brass monkeys weekend, particularly on Saturday which for us in The Midlands was damp, cold, sleety and grim. I was fishing and it got to the point where I couldn’t feel my finger tips I was that cold.(still caught though :))

This week of the year has more often than not been mild, muggy and warm with high day and night temperatures, but as we can see from the graphics above, that certainly isn’t the case this morning with a hard frost for October !

Last week the projections for this week were cold and settled breaking down into a milder, wetter, south-westerly air stream, but were they correct ?

General Weather Situation

So Monday starts with a cracking deep frost in many locations and lots of bright winter sunshine. A good day for winter projects. That’s the way it looks across nearly all of the U.K and Ireland, note I say ‘nearly all’ because the west coast of Ireland looks to flirt with a heavy rain band and at this stage the projections are that it’ll push about 50-70 miles (my guess) inland all the way from Kerry up to Donegal making landfall mid-morning. Elsewhere it’ll be bright, dry and cold with temperatures maybe not even breaking into double figures. Enjoy it though because a change is on the way. Wind-wise we will still have that north-easterly in situ, though it may be more easterly further north and that’ll give significant windchill.

Onto Tuesday and it may not as cold overnight with more cloud cover around. Now here’s an interesting one as a band of heavy rain is projected to push over from France into south-east and eastern England after midnight, caused by a Bay of Biscay low pushing up from France. This band of rain will extend northwards through the morning and as it meets colder air across the north-east of England and eastern Scotland, there’s a chance that the rain will become more wintry. The projections are that the rain will push inland to around the A1 sort of area and no further westwards but we will see, continental rain is notoriously difficult to predict. We may also see some rain later in the day for Kerry and around mid-north Wales as well. Across Ireland that rain front will push cloud ahead of it so a much duller day here, the same for Scotland. In between that rain sandwich, they’ll be a strip of clear, colder and brighter weather conditions. The wind swings round overnight to a more north-westerly perspective and picks up some force to become strong to gusty through the day and swinging round to westerly at close of play. Similar temperatures to Monday with high single figures and maybe a risk of ground frost on Tuesday night in sheltered areas if the skies clear.

Wednesday sees that low push north and east into Scandinavia leaving us a cold and settled day and a slightly milder one as the wind is from the south-west for most. As well as a milder air stream, that shift in wind direction will push in some showers off The Irish Sea across North Wales and into north-west England as well. Later in the morning we will also see some showers crossing the west coast of Ireland and north-west Scotland. The showers will consolidate into heavier rain across the west and Midlands of Ireland towards dusk and push into the north-east of England. Slightly milder temperatures in that south-west wind just breaking into the double figures across the south of the U.K, but across Ireland and Scotland you may stay a couple of degrees below this.

Onto Thursday and a pretty ‘busy’ weather picture with a band of rain moving overnight off the continent into the south-east and east of England. At the same time we see a westerly rain front pushing into the western coastline of the U.K bringing some showers to The South West and Wales. The heavier rain though will be across The Lakes and extend northwards into the west of Scotland where it’ll become increasingly wintry in nature across higher ground. By mid-morning most of that rain should have cleared away to leave brighter conditions behind for most of the U.K and Ireland. The exception could be a condensed band of wintry showers over the central highlands of Scotland. A much better 2nd half of the day, still with the risk of showers across north-western coasts and western Scotland, but away from this, dry, bright and cool with the temperatures stubbornly staying in the high single figures.

Image courtesy of Unisys Weather

Closing out a busy weather week and the above picture sets the scene not just for the 2nd half of Friday but also the weekend as well. The Unisys graphic above shows a very deep Atlantic low that is due to swing in on Friday so after a quiet start for most places,  we will see rain push into Ireland from before dawn. This will quickly push across the country if anything intensifying over south-west Munster. By mid-morning it’ll be into The South West and South Wales and thereafter it’ll push quickly eastwards with some heavy rain predicted for West and South Wales. During the early afternoon it’ll have reached the north-west and west of Scotland and as we approach dusk, it’ll be pretty much countrywide bar maybe the north-east tip of Scotland. The only consolation for what looks like a pretty grim day is that it’ll feel milder (the rain will be warmer) in a strong south-westerly wind with temperatures into double and nudging the teens.

So no surprise then that the weekend looks pretty unsettled, wet and very, very windy, especially on Saturday. On the plus side if you’re on Strava, a great opportunity to get a KOM with that following wind 🙂 So Saturday looks unsettled from the off with that overnight rain still ever-present. Through the morning it should clear the south of England and most of Ireland, though showers will remain. The heaviest rain as usual when we talk Atlantic low pressure systems will be reserved for the north and west with The Lakes in particularly looking very wet. Dull and mild(ish) away from the rain with temperatures again into double figures. As mentioned earlier with packed isobars it’ll be very windy. Sunday starts off with a showery outlook but that low is spinning around again on lap 2 and if anything it’ll sink further south to bring heavy rain to Ireland for the 2nd half of Sunday before this pushes into Wales and England later on Sunday. A cooler feel to the weather on Sunday as well.

Image courtesy of Unisys

Weather Outlook

The above GIF shows the pronounced ‘trough’ pattern at the beginning of next week and that means the low pressure that we are due to receive at the weekend isn’t going anywhere fast.

A trough pattern in the jetstream means sequential low pressure systems can just slip down into it giving successive bouts of heavy rain and that’s what we are likely to see next week. So Monday looks to start the week extremely wet with heavy rain forecast for the west of the U.K initially pushing south and east across the southern half of the U.K and sparing the north and Scotland from the worst. Tuesday sees a quieter day but that lull will be a temporary one because Wednesday will see a new low enter into the picture and bring heavy rain for The South West, Wales and the south of England. Thursday again sees a lull before the possibility of a new low for Friday / next weekend as that trough shows no sign of shifting. With the centre of the low pressure systems located south of the U.K, I think Ireland, the north of England and Scotland will miss the worst of this rainfall and here will just be unsettled.

Agronomic Notes

Since we are nearly out of October let’s finish off the exercise I did mid-month looking at how October 2018 has tracked vs. 2017 / 2016. The 2nd half of October 2018 finished off a good bit cooler than the two previous years and that’s meant good news for fungicide longevity and disease activity (or lack of it).

Below is the relative G.P for the last 3 October’s.

You can see the previous two mild and muggy Halloween’s compared to this one which will be on the nippy side. (Cue multiple Supermarket hype followed by Black Friday and Christmas, all Hampsters to the wheel 🙁 ).

This October we have had that cold, Arctic air stream with snow in places at the weekend and that has depressed air temperature and of course Growth Potential. As with most aspects of turf management there are two sides to every coin and the plus side of this one is undoubtedly reduced Microdochium nivale pressure along with extended fungicide longevity due to the low grass growth rate.

Below shows a comparison of October 2018 vs. 2017 / 2016 assuming a fungicide application was made on October 1st. Just like in 2017, we had a really tough situation mid-month with a peak in Growth Potential coinciding with a peak in Microdochium nivale activity. That meant a lot of fungicide applications were on their way out just when disease pressure ramped up. (see below)

 

As mentioned above there is a flipside to this coin and that comes in the form of lower soil temperatures which will slow germination and new seedling growth from the very many overseeding / renovation processes carried out during September and October.

That said I reckon the soil temperature will pick up as we go into November because the rain we are forecast will come on a milder air stream so that will increase the soil temperature nicely.

I know the prognosis for the end of the week onwards looks wet but to be honest in a lot of places in the U.K we desperately need the rain with low ground water levels and restrictions on the horizon for 2019 if we don’t get sufficient rain over the autumn / winter. So in other words, we shouldn’t moan because we need it.

Disease Pressure Outlook

Looking at the next 7 days the prognosis from our disease projection models is for low Microdochium pressure so that’s October taken care of disease-wise.

It’ll be interesting to see how this develops through November because I keep seeing chatter about the possibility of a Sudden Stratospheric Warming Event during November, which would be remarkably early. If you remember, we had one of these earlier in the year and it was responsible for the very cold (and wet) end to winter 2017 / 18.

Hopefully it is just meteorological speculation.

We can’t be complacent though because December has bit us in the you-know-what Microdochium-wise in 2017 and 2016 with a very mild run of weather in the first week of the month and over the Christmas period. I still get the feeling we are in for a cold one, as nature continues to confirm, with lots of Waxwings, Redwings and Fieldfares arriving from the east, so we will see.

Ok that’s it for this week, I hope to see some of you at Saltex if you are attending and unlike last year, I will make sure I turn up for my allocated presentation slot at 12pm, Thursday 🙂

All the best.

Mark Hunt

 

22nd October

 

Hi All,

You get some beautiful sunrises and sunsets at this time of year don’t you ?

This was the scene that greeted me early on Saturday morning at Thornton Reservoir in Leicestershire. Sadly it’s likely to be a thing of the past come the end of this week when we pull down a distinctly Arctic wind and that’ll bring the first taste of winter for all of us I reckon. Some of the weather sites are getting excited about the possibilities of snow on higher ground even across the south of the U.K.

Difficult to believe when yesterday I was walking in shorts in a nice and sunny 18°C, but that change is a coming and  due to us moving from a peak to a trough pattern in the jet stream.

Over the last 9 years, the coming week has typically been one of the mildest weeks of the autumn with 7 out of the last 9 producing temperatures in the high teens and even low twenties, but not this year.

Image courtesy of Netweather

Our old friend the jet stream is responsible for this cold blast and apparently it’s doing the same thing along the west coast of America. You can see its orientation clearly in the Netweather graphic above.

Nature as usual seems to be ahead of the game meteorologically-speaking because yesterday I noticed lots of Redwings and Fieldfares flying overhead and landing on the copious Hawthorn berry crop in the hedgerows. I see there’s also been reports of the first Waxwings (above) into Scotland, Yorkshire and Norfolk. Now they are one sign of winter I absolutely love. I took the photo above of a Waxwing in the winter of 2013, just outside of Loughborough Railway Station. All of these bird species typically spend the summer in Finland and Russia before heading west to the U.K to over-winter in our relatively mild conditions on our berry crop. Maybe they know something we don’t but the signs from nature are starting to suggest to me that we are possibly in for a hard winter…

General Weather Situation

Ok, so we start the week on Monday with a clear cold start (looking out of my office window) and that’s the way we are set to stay today for practically all the U.K and Ireland. More cloud across Ireland and the west of the U.K initially but this will clear through the morning to give long spells of autumn sunshine pretty much everywhere apart from the far tip of Northern Scotland where it’ll stay. It won’t feel warm though as the wind will have a distinctly northern chill about it (though nothing compared to the end of the week) so temperatures across all areas will struggle into the low teens only despite the sunshine.

With clear skies overnight, expect to start Tuesday chilly again over most places though the west and north will pick up some cloud overnight. This is the result of a rain band that is set to push into north-west Scotland during the morning and head south into south-west Scotland by lunchtime. Further south and west of this across Ireland, Wales and England, expect another cold, bright and pretty windy day as those isobars close together and really ramp up the wind strength. Milder on Tuesday due to a north-west aspect to the wind with temperatures creeping up towards the low to mid-teens despite the strong wind. A good drying day.

Overnight into Wednesday we see that rain in situ over north-west Scotland and much more in the way of cloud for all areas to start the day. This cloud will gradually thin to leave a hazy outlook across most areas and plenty of sunshine as well. Across Co. Cavan and the north of Ireland I think it may be slow to clear, the same across the north-west coast of England and Scotland. Not as windy on Wednesday so we keep the mild feel to the weather with mid-teens the order of the day over Ireland, Wales and England and just breaking into double figures across Scotland with that thicker cloud cover.

My the week is flying by and Thursday will probably be the last ‘mild’ day of the week with a cloudier start to the day on the cards. A pronounced west wind as well will keep those temperatures decent but it’ll also be responsible for pulling in some rain to north-west Scotland and a much thicker cloud base to Connacht, Donegal and the west of Scotland to boot. Further south another decent day, more in the way of cloud about but some nice breaks of sunshine as well. So again a good drying day with that moderate westerly wind in place.

Overnight into Friday and we will notice two features of the weather, the first a swing from westerly to northerly in terms of wind direction and the second a strengthening of the wind to strong / gale force. This will have an immediate impact on temperatures in the north with them not likely to make double figures despite a sunny day being on the cards. We will also see a rain front push down quickly across Donegal, Connacht and the north west of England overnight into Friday and this may bring some wintry showers for high ground over The Lakes overnight. It should have cleared by dawn though.That change in direction and strength of the wind will be felt across Ireland, England and Wales and again despite the fact that we should see plenty of sunshine, it’ll feel pretty chilly in the wind. So maybe in the south of England you’ll make it into double figures temperature-wise, but elsewhere 7-9°C is likely to be your best.

If you think that’s a bit poor, wait for the weekend 🙁

Talking about the weekend, well overnight into Saturday we will see that northerly air stream pull in a mix of wintry showers across Scotland, the north of Ireland but also along some north-west and north-east coasts as well. We may be cold enough for a ground frost as well in some sheltered areas. A mixed picture on Saturday with some sunshine but also the risk of rain across all areas particularly for the first half of the day turning to sleet and wintry showers across higher elevations. That wind will be due north on Saturday, maybe north-east on Sunday and despite the possibility of plenty of sunshine on Saturday and Sunday as well, it’ll feel really raw with 7°C likely to be the maximum temperature. It’s all about the the wind chill though with temperatures not much above freezing in the wind further north. Sunday looks a bit cloudier but still we will feel a strong north-east wind and cold day / night-time temperatures. Ireland may just break double figures being further away from that cold air stream but it’ll still feel pretty parky.

Weather Outlook

So after our winter weekend, how does next week look ?

Well that cold theme will continue through to the start of next week with Monday looking cold and wintry with the risk of some wintry showers along eastern coasts and still windy from the north east. Overnight into Tuesday we see some rain and wintry showers push across Ireland and into the west coast of the U.K and we should notice a drop in the wind so to me that means a risk of frost. That risk continues through Wednesday but we then see a Bay of Biscay low come into play and that’ll swing the wind round to the south for Thursday introducing milder and wetter air into the forecast. So I expect a wet and windy end to next week but milder with it.

Agronomic Notes

Microdochium nivale pressure – what else ?

It’s October, it’s been mild and humid so what else is there to start this blog with but Microdochium ?

I mentioned at the start of last week that we had a critical period coming up with lighter winds, high overnight temperatures and the possibility of dew formation and indeed that’s what we got. Consequently we saw plenty of Microdochium nivale activity at the start of last week, Monday and Tuesday in particular.

It wasn’t that straight-forward though because a number of you mentioned a repeated requirement to remove dew from surfaces during the day with it consistently re-forming.

Although we did see dew last week, we also saw a related phenomenon, Guttation Fluid, courtesy of that very wet Sunday (14th October) loading up the soil moisture level.

I took the picture below at 10.15 a.m. on a golf course last Tuesday and you can clearly see the droplets of Guttation Fluid on the tips of the grass plant leaf. (Bloody spellcheck keeps trying to change this to Gas Station !)

So what’s the difference between dew and Guttation Fluid ?

Dew is simply moisture condensing from the atmosphere when we reach 100% humidity. The dew point is the predicted temperature when dew will start to form and when the air temperature drops to the dew point temperature that is what we are supposed to see, i.e dew formation, but it isn’t quite that straight-forward when we are dealing with grass…

What I have noticed is that the air temperature doesn’t have to equal the dew point temperature for dew to develop on grass. This is because the grass leaf loses heat to the atmosphere (particularly on clear nights) and consequently cools down quicker than air temperature. So that means the actual grass leaf surface temperature is lower than the air temperature.

In the weather station readout below you’ll see the air temperature is 1.5°C and the dewpoint is calculated at 0.8°C, so theoretically dew shouldn’t be forming as the air temperature ≠ dewpoint temperature. As you can see from the accompanying image below, the reality was very heavy dew formation on grass. (Thanks Sean for this)

Ok that’s dew but what is Guttation Fluid ?

Simply put, Guttation Fluid is exudate from xylem sap that is forced out of the tip of a grass plant leaf through holes in the tip called hydathodes. Since it consists of xylem sap it contains water, nutrient salts and sugars that are normally transported up from the roots to the leaves of the grass plant. When we have heavy rainfall, water pressure builds up in the roots and then the xylem, forcing water up through the xylem vessel and out of the grass leaf tips. As Guttation Fluid evaporates, you can see white crystals of these salts and sugars forming on the plant leaf tip, initially I thought this was fungus forming but it’s actually nutrient salts evaporating. I snapped this phenomenon on a golf course awhile back, see below ;

Guttation Fluid will reform after removal if the pressure gradient is still present from the roots to the grass leaf tips and that’s why the presence of Guttation Fluid is more of a problem than dew when it comes to disease.  It’s not just the reformation that marks it out as a contributory factor to disease development..

As mentioned earlier, in a droplet of Guttation Fluid, we have everything a fungus needs to live and as far back as 1968, the formation of Guttation Fluid was linked with increased levels of foliar diseases like Dollar Spot.

So we last week had a wet grass leaf, a combination of dew and Guttation Fluid, high overnight temperatures, high humidity and low wind levels.

In other words perfect conditions for Microdochium nivale development.

Not surprisingly that’s what we saw with very high levels of disease noted across the U.K early last week. Ireland and Scotland had a much lower disease pressure because they were colder, brighter, drier and had less humidity. I have used some disease prediction models I am developing to map out disease intensity this autumn and I think it makes interesting viewing.

So you can see last week we had moderate to high disease pressure culminating in a peak on the night of the 15th, morning of the 16th of October. On this date you may have noticed lots of mycelium development on the grass leaf particularly on untreated areas like approaches, tees and outfield turf.

The previous last peak of this magnitude was way back on the 27th August, but it is unlikely you would have noticed the same phenomenon and that is because of growth levels and evapotranspiration. Back at the end of August we were at optimum growth and so even though we had high Microdochium pressure we didn’t see the same level of disease on the turf surface because it was growing so fast plus E.T levels would have been higher. (drying the leaf down quicker)

Fast forward to last week and although we had some growth peaks, we also had some growth troughs in G.P, which indicate slower grass growth and therefore more significant damage potential from Microdochium nivale. Also E.T levels were low last week so the grass leaf stayed wetter for longer, further increasing disease intensity.

So that’s hopefully a pretty broad explanation as to why last week presented some significant challenges from a disease management perspective.

On the plus side I think we are already learning the lessons of ‘life after Iprodione’ with many clubs putting in place good systemic fungicide programs interspersed with non-pesticidal, disease-suppressant sprays. In addition the important take-home message of reducing the interval between sprays during this month when growth is still significant (despite the troughs) is also providing better efficacy in terms of disease control.

All in all I think we are well-advanced in the process of observing, learning and adapting to the new environment of disease management without the safety net of contact, curative fungicides. That can only be good news for our industry.

In recent weeks it occurs to me that I’ve talked a lot about fungicide efficacy and not a lot about Best Management Practices but that doesn’t mean I see this as secondary, far from it. The reality is that of the contributing BMP’s to better disease management, I believe surface organic matter is the most significant.

The days of getting by without doing sufficient aeration to reduce surface organic matter levels in the top 25mm are behind us, those that think they aren’t are in for a wake up call.

Sure there’s always a reason not to do it, like there’s never a good time to take a holiday when you have a high workload ( 🙂 ), but with the twin challenges of climate and legislation our industry cannot be complacent in this area. I 100% understand the commerciality of running a business and the negativity surrounding aeration but the flip side of having heavy scarring from October to April and poor surfaces (that will not justify a high round cost nor recover till late in spring) has to be considered in the mix as well. Like everything in life it comes down to willing partners working to find compromise and good two-way communication, something incidentally the Brexit process looks to be bereft of 🙁

Next week I will focus on this area specifically looking at aeration dates vs. recovery vs. disease pressure but for now I’ll sign off with having a quick look at the coming 7-10 days from a disease management perspective.

So looking at the disease projection matrix in terms of the forthcoming early winter blast, it’s no surprise that we see very little disease peaks on the horizon over the next 7-10 days. Dove-tail this lower disease pressure with a low weekly GDD / G.P projected total and it’s further good news for fungicide / non-pesticidal mix longevity as well.

So if you’ve got this far with good surfaces, you can relax for a little while but we must remember that in the last 2 years early December has given us a pretty nasty sting in the tail disease-wise, so we shouldn’t be complacent.

Until next week, all the best.

Mark Hunt

October 15th

Hi All,

Well last week was one week I probably didn’t want to miss when publishing a weather blog but it was unavoidable. Gale force winds, torrential rain and scorching high temperatures were all packed into one week in October together with record high, night temperatures and a 15°C temperature drop from Saturday to Sunday.

Digressing from the weather for a mo’, I did have a good deal of correspondence asking what I was doing on that Monday, in particular a certain James Watson suggested I might be getting married. (ha ha) Nice one James, glad to see your imagination is as over-enthusiastic as ever (like your shirt choice) but clearly not a realistic proposition 🙂

Actually I was competing in the Troutmasters Final at Draycote Water, which is a national competition and quite challenging mentally and physically as I found out.

Bearing in mind the long-held viewpoint (by many) that fishing involves sitting staring at the water and doing nothing for long periods, I think my Garmin readout for the day suggests otherwise. Fly fishing is a different matter because you cast a lot and competition fly fishing even more physically demanding because of the pressure. Don’t normally like blowing my own trumpet (Law of Jante and all that) but I managed to finish a lucky 9th out of 100-odd competitors which I was chuffed with 🙂

OK, enough of the fishing, onto the weather and are we in for another week of gales and rain or is there more of a settled aspect to the job ?

General Weather Situation

After yesterday’s rainfall and much cooler temperatures, Monday continues to follow that trend with a dull, cool and in some places, extremely wet start to the week. There’s a raft of heavy showers moving up across London and eastern counties and further rain north and west of that. Now for Ireland and Scotland it’s the reverse with a cool but sunny start for both as you kick off the week. Through the morning this band of rain will stretch in a line extending from South Wales up to The Humber and it’ll slowly move northwards through the day. East and west of this line you’ll see a dull and cool 2nd half of the day really with the sun not breaking through till we head north of The Pennines. So cool and dull across England and Wales with that central rain belt staying in situ most of the day, contrasting strongly with bright, sunny and dry for Scotland and Ireland. Light southerly winds across the latter but fresh, north easterlies across England and Wales will keep temperatures down to low to mid-teens across all areas. Mild overnight.

Onto Tuesday and overnight that rain clears off into The North Sea to leave a dull, dry start to the day. It won’t stay that way for long as a rain front is set to push into the west of Ireland around late morning reaching Connacht first and then slowly moving eastwards pushing thick cloud ahead of it. Contrast that with the south-east of England which will have a bright, cool and dry day as will most of the U.K, but further north and west we will see more in the way of cloud and less in the way of sunshine. That rain is set to reach Leinster by late afternoon clearing the west as it does so, whilst across The Irish Sea, we see the northerly extremity of that rain reach north-west and Central Scotland by sunset. So not a bad Tuesday for the U.K, cool, dull and wet for Ireland. Temperature-wise, similar to Monday with mid-teens typical, although the wind will swing round to the south over most areas. Mild overnight again unfortunately.

Mid-week and Wednesday sees that Irish rain band move across into Wales and western England overnight so by dawn it’ll be sitting over the West Midlands, but diminishing in terms of rainfall levels as it does so. Away from this narrow band of rain we will see another dull and mild start to the day with maybe some hints of sunshine across The South East, East Anglia and along the east coast of the U.K. This rain band is projected to extend from the Isle of Wight all the way up to The Wash and pretty much sit there all day with more showers joining it from the west and east later on Wednesday. For Ireland, Scotland and northern England, a dry day with some sunshine and plenty of cloud as well from the off with maybe the odd chance of a shower over Ireland. As we approach dusk we see the cloud lift over Scotland and northern England signifying a much cooler night in store with single figure temperatures. Further south over England and Wales, that cloud cover is set to stay so again double figure temperatures but maybe not as mild as earlier in the week. Winds will be light and southerly.

Thursday sees that central band of rain still sitting along the M5 sort of direction and here it’ll be accompanied by thick cloud as well. East, west and north of this, another dry, cloudy day with some sunshine breaking through during the morning. By lunchtime that rain band has finally fizzled out to give a dull, but dry 2nd half of the day across The Midlands. So dry in most places, dull and remaining on the cool side with low to mid-teens the order of the day for the U.K and Ireland. One reason for the extended period of dullness is a change round in the wind to the north-east and an increase in strength pushing cloud in off The North Sea.

Friday rounds out the week with more of the same really with most of the U.K and Ireland starting off dull if a little cooler courtesy of that north-east wind, though The South East may see some sunshine. As we approach late morning we see a band of rain push into the west of Ireland and Scotland and this will slowly progress eastwards over lunchtime and into the afternoon with maybe more rain across south-east Munster and the west of Scotland and not central areas. For England and Wales we will see the sun break through during the afternoon so not a bad 2nd half of the day at the end of the week and with a much lighter, westerly wind, it’ll feel a little milder possibly. So a wet, dull end of the week for Ireland and Scotland and a brighter, hazy, dry end for Wales and England. Similar temperatures to the rest of the week, maybe a degree or two higher across England due to the lighter westerly wind.

The weekend forecast is a bit of a north-south divide with the north of the U.K and Ireland affected by strong winds and low pressure vs. central and southern regions which pick up an Atlantic high pressure system. At this stage I think Saturday will see cloud and rain over Scotland and maybe Ireland for the 1st part of the day before clearing easterly afterwards. It’ll feel warmer across the west first as that Atlantic high pushes in. Further south I think we should miss this rain and instead have a largely dry and dull day with a moderate to breezy south-west wind. I think the worst of the rain for Scotland pushes through overnight into Sunday morning before clearing to give a better Sunday after early rain. Across Ireland I think Sunday may still see some showers across the west but for Wales and England a much better weather picture with warmer winds and sunnier intervals pushing up temperatures into the high teens in the sunshine.

Image courtesy of Netweather

Weather Outlook

With high pressure pushing in from the weekend, next week looks to be a battle of low vs. high where high wins out, so despite the start of next week looking a bit unsettled with strong northerly winds and some rain showers, I think the weather will calm down soon after this and allow high pressure to dominate bringing calm, settled and mild conditions to the fore with light winds. The Netweather graphic above shows a high jet stream position mid-way through next week pushing winder and wetter weather over us before it takes a sharp right and pushes cold air down into Scandinavia and Central Europe.

Agronomic Notes

It’s been a really interesting weather dynamic over the last 7 days or so and one that makes me realise how little we understand about disease dynamics with respect to Microdochium nivale.

I will drill down into it from a weather conditions vs. disease population growth dynamic later but first off let’s look at October 2018 vs. the previous two years to see how it pans out…

Daily Growth Potential Comparison – October 2018 vs. 2017 vs. 2016

What we are looking at here is Growth Potential for this month over the last 3 years and you can clearly see the peaks and troughs. October 2016, was a reasonably cool month with lower than normal G.P figures but last October you’ll remember we had some particularly aggressive Microdochium nivale activity coinciding with the middle of the month and extending on into the third week of the month (red dashed line).

This year we have had two G.P peaks culminating with the one that began last Tuesday and lasted until Sunday when the wind direction changed to north dropped the daytime temperature and G.P significantly.

I have used the projected day and night temps to plot out the projected Growth Potential (faded green) for the next 10 days and you can see we have a couple of daily peaks coming up but we shouldn’t be as bad as October 2017 from a growth perspective.

That is significant because of course growth this late in the season is a double-edged sword isn’t it ?

Firstly it can be very beneficial in growing out disease activity but secondly of course it will also grow out fungicide applications leading to reduced longevity.

Cumulative Growth Potential Comparison – October 2018 vs. 2017 vs. 2016

We saw this in 2017 if you remember, when we had a very warm month with elevated periods of grass growth. I work off a cumulative Growth Potential figure of 10 for a systemic fungicide application based on my observations in the field and in research trials.

Now there’s a fair % of SWAG (Scientific wild-arsed guess – Copyright Dr Jame Beard) here and I accept it is also wholly-dependent on lots of variables, not least your grass species, level of nutrition, PGR usage but above all the effectiveness of the fungicide active ingredient (s). A more effective A.I may go longer, a less effective one, will definitely last less.

I’ve plotted out the cumulative G.P for the last 3 October’s, workeing on applying a fungicide on the 1st of October and then seeing how many days it takes to reach a cumulative G.P of 10, the results are interesting…

So what we see is that in both October 2018 and 2017, the predicted systemic fungicide longevity is pretty much identical at 14 days, whereas in October 2016, this extended to 26 days because it was cooler. I’ve plotted out the cumulative G.P for the next 10 days and you can see the good news is any application made now should be lasting longer because we are set to be cooler than October 2017 for the second half of the month 🙂

Disease Dynamics

Now let us consider the dynamic of systemic fungicide control vs. fungal population growth.

First off when we apply a systemic fungicide there is a lag period before it is present in sufficient concentration to combat fungal growth. Now the more effective the active ingredient, the shorter this lag period because lower doses achieve better control, quicker and vice-versa. Once in the plant, there is then the ever-present dynamic between rate of fungal growth vs. rate of population reduction by the fungicide A.I.

Now two of the most important factors affecting fungal growth are plant leaf wetness and temperature and last week was so-so interesting when we look at the dynamic between these factors.

On one hand we had really high air temperature at night which for sure was promoting fungal growth, but on the other hand we had a really strong wind and not only was it strong, it was warm, so it was drying the grass leaf. This resulted in very little dew formation and so we didn’t see lots of disease, in fact some sites reported no Microdochium activity at all. Others noted disease ingression from the 10th of October, but more so on the 12th, when the night-time temperature was > 15°C and the humidity increased as well.

We were on a real knife-edge though and depending on your site dynamics you may have seen no disease if you manage an ‘open-aspect’ location or you saw varying levels with the difference noted between shadier and open-aspect greens.

I have used the output from 2 different weather stations, one sited in a reasonably open location, the other in a sheltered one. The geographical locations are different but you can see in the open-aspect location how the humidity just hovered below 90%, enough to avoid aggressive disease, whereas the other sheltered location recorded a much higher level of humidity.

I have circled the night-time temperatures in both graphs and you can see the high air temperature during the night of the 12th / 13th of October, however if you look at the humidity you can see if tops out above the 90% mark in the sheltered location but stays under it in the open location. This was due to the effect of the wind reducing humidity in the open site location.

That night-time temperature on the 12th / 13th October was a record for October in many locations and here in Market Harborough we didn’t dip below 17°C all night !

Tipping of the balance

If you were in a location where the humidity increased on that night above the critical value and you picked up +17°C, you would have seen Microdochium nivale activity no matter whether you had an effective fungicide down or not. The difference of course would have been the severity of the damage but for sure the balance would have tipped very much in favour of fungal population growth to the detriment of fungicidal control, no question.

Disease activity outlook for the coming week….

Well again we have an interesting dynamic, quite different from last week.

OK, it depends entirely on your location and that’s where trying to generalise on this blog does me no favours but the dynamic this week is one of cooler night temperatures but critically lighter wind speeds which will allow for higher humidity levels and hence dew formation. If I look at 6 different locations across the U.K, I think that Tue night / Wed morning represents the highest likely disease pressure this week. After that the temperature at night should drop off nicely and the wind speed will probably stay high enough to decrease dew formation.

High soil temperatures means there’s still time to get recovery on worn areas…

After the very dry (and already forgotten in some quarters) summer, we have a lot of thin / worn and bare areas on golf and outfield turf alike. Last weekend in Leicestershire marked our first decent rain that will have wetted down through the profile so is it worth continuing renovating these areas ?

Definitely so in my books because we are retaining plenty of soil temperature necessary for seed germination and we have soil moisture as well. I remember awhile back we had a very dry summer and autumn to such an extent that a lot of clubs didn’t renovate bare areas till early November. They overseeded as well and I thought it was a waste of time but it wasn’t because those areas got away before the winter and recovered quicker the following spring.

The graph below shows where we are soil temperature-wise vs. previous years…

Ok a long blog for this week, that’ll teach me to take a week off 🙂

All the best.

Mark Hunt

 

 

 

 

 

 

 

 

 

October 1st

Hi All,

It may be just me but September 2018 felt very much like we were firmly set on the road to autumn / winter and not a continuation of summer. We’ve had 3 ground frosts here last month and I can’t remember getting close to that last year. There are also some signs from nature that we are cooling down quicker this year with a lot of the Martins and Swallows already away on their migration south and I’m pretty sure I heard a Redwing yesterday, newly arrived from Scandinavia to feast on what has to be said is a mega berry crop in the hedgerows. If so that would be 2 weeks earlier than usual. Meteorologically-speaking, some of the longer-range forecasters are stating that we are in for a cooler than usual October, but we will see, long-range is notoriously fickle when it comes to our climate and the jet stream. I charted out the temperatures at my location for September 2018 and 2017 using data from my Netatmo and you can see the difference in temperatures (particularly minimum temperature)

Onto this week’s weather and the prognosis last week was for an extended stay of high pressure, so we shall see if it was right.

General Weather Situation

So we start off on Monday with an Atlantic high pressure butted up against a cold, Arctic low sat over northern Scandinavia with the result that the wind is funneling between them from the north. So we are noticeably cool to start the week, down in single figures. A dry, bright and sunny day for most areas with some high cloud across the west and just a few showers dotted over East Anglia, Wales and Co. Clare. That’s the way we should stay for most of us but Scotland will see thicker cloud through the afternoon and the arrival of heavy rain into the north-west later this afternoon. It’ll be cool enough for this to fall as sleet over elevation. Through Monday evening this band of heavy rain will move south across north-west Ireland and western Scotland, accompanied by a freshening wind blowing from the west up north but firmly from the north further south making it feel nippy even in the sun. So that wind will keep temperatures down to the low teens for Ireland and Scotland and maybe a degree or two higher further south.

Onto Tuesday and that band of rain has sunk south overnight across Ireland and down the west coast of England into Wales and that’s where it’ll reside first thing. So a wetter start for the north and west on Tuesday but as we go through the morning that rain will fizzle out over Ireland, Wales and The South West to leave a clearer and milder 2nd half of the day. Away from this rain front we see the wind change from north to north-west, but it’ll keep on blowing hard ushering in warmer air from that high pressure. So despite being windy it’ll also be warmer on Tuesday with mid-teens for Ireland and Scotland and high teens, possibly even 20°C for South Wales and the south of England. Windy and warm then but plenty of cloud around as well.

Mid-week and Wednesday sees a continuation on that theme with warm and dry conditions for central and southern England, along with Wales. Ireland stays dry as well with pleasant enough temperatures in the mid-teens. As we progress north we see more in the way of cloud cover building from the north-west and that’ll usher in some thicker cloud, rain and drizzle during the late afternoon into Scotland and later northern England. More in the way of sunshine for the east of England and again here we may see temperatures hit 20°C in the lighter winds on Wednesday. Mid-teens for Ireland and low teens for Scotland under that thicker cloud and light rain. The winds will be lighter and from the north-west / west for Wednesday.

Onto Thursday and overnight we see that thicker cloud and rain extending south across Ireland, Scotland, the north of England and North Wales so a cooler feel to the weather as we approach the end of the week. More in the way of cloud cover with a strong to moderate westerly wind as well. That rain will slowly fizzle out and dissipate but may stay stubbornly entrenched over North Wales and The Pennines. As that cloud thins we should see sunny intervals end the day across the east of Scotland, The North East and possibly further south as well. So mid to high teens for England and Wales, but cooler over Ireland and Scotland as the wind flips back to the north / north west. Those winds will be particularly strong over Scotland.

After a mild night everywhere we see a much better weather picture for Friday with a lot of dry weather around and some sunshine across the east of Ireland and England. Through the morning we see more cloud build as a prelude to rain pushing into the north of Ireland and west of Scotland. We may also see some thicker cloud into The South West and along the south coast of England through Friday morning with some of it thick enough to bring some rain. The majority of areas away from this will have a dry, warm and pleasant day but they’ll be more cloud around as we go through the evening. It’ll feel cooler again as that northerly wind provides a nip in the air. Later on Friday night we see another rain front push into Northern Ireland, western Scotland and the south-west of Ireland. Mid to high teens for England and Wales but with that thicker cloud across Ireland and Scotland, along with lighter winds, temperatures will barely scrape into double figures.

So next weekend looks a bit mixed really with that rain moving across all areas of the U.K and Ireland overnight into Saturday. There’s a risk that some of it may be heavy across The Midlands and East Anglia through Saturday morning as a low pressure pushes in from The Bay of Biscay, but the flip side is that Ireland and Scotland should miss this so here you’ll see more in the way of sunshine. As we go through the morning into the afternoon we should see a much brighter 2nd half of the day for Wales as the weather clears from the west, but it’ll still feel on the chilly side with low teens across England and Wales and low double figures across Scotland and Ireland, even in the sunshine. It’ll be pretty windy on Saturday with those isobars tightly packed pulling in northerlies so that means cool with a capital ‘C’ and a great day to do indoor jobs or tie flies 🙂 Sunday looks a much quieter day as high pressure again pushes in from the west so dry, settled with milder westerly winds and plenty of sunshine. Scotland though looks cooler and dull I’m afraid.

Weather Outlook

So does that high pressure pushing over the 2nd half of the weekend mean we are in for more settled weather or will the gathering Atlantic storms finally win the day ?

Well next week to me looks like being a transition week from high pressure to low pressure.

The weather scene is that we have a deep northerly, low pressure slowly squeezing away an entrenched southerly high pressure residing over The Bay of Biscay through the course of next week. So it looks like it’ll be settled and largely dry for the south of England, Wales and the south of Ireland for the first part of the week. Further north across Ireland and Scotland you will feel the influence of that low pressure with stronger winds and rain through the 2nd half of  Monday, Tuesday and Wednesday. At this stage it doesn’t look like that rain will extend its grip to the south but all areas will have a predominantly south-westerly airflow. Thursday looks like being a bit of a hiatus for all areas before I think a succession of low pressures finally push the high out of the way and bring rain and strong winds for the end of next week / weekend. My guess is with a south-westerly airflow we will see mild temperatures day and night but with an ever-present wind hopefully not the still, muggy balmy nights we just don’t need at this time of year.

Agronomic Notes

First off we will start with a look-see at our usual GDD data from The Oxfordshire location for September 2018.

Looking at the stats from a GDD perspective September 2018 looks pretty similar to September 2017 from a growth potential perspective and pretty average really which is surprising to me because I would have bet on it being a lower GDD month. (Just goes to show what I know)

Cumulatively that puts us in a very similar, if near identical position to 2017, which again highlights the way we have caught up so much from this perspective. That said I know you’ll say well we might have had very high GDD through June, July and August, but it didn’t actually reflect in growth because the grass plant was moisture-limited and for most species the temperature was above-optimum for growth. That is of course one of the drawbacks of GDD in that it has no ‘top out’ whereas Growth Potential does, so when I get the time I’ll plot the same stats from a G.P perspective or I might just throw that job Wendy’s way (cue running for office door sounds 🙂 )

Soil Moisture Status

It was only a week ago odd that I was driving along the M1 in Yorkshire aquaplaning between Costa Coffee stops so I know for some of you this next bit will seem a bit academic. We know it’s very much been a north-south split rainfall-wise this autumn so far and whereas the north has had some pretty horrendous rainfall totals, the same cannot be said from The Midlands south.

Here we are still extremely dry, the rivers and reservoirs are still at below summer level so I have continued by exercise from earlier in the summer for soil moisture surplus / deficit using data sent in by Sean at The Oxfordshire, a location that tends to be on the dry side I’d say and quite representative for that reason.

So here’s where we were at the end of September last year at this location ;

A net moisture deficit of 149.4mm from June 1st to September 30th, 2017, which reflects a change of -3.7mm from the end of August 2017. So in other words during September last year the difference between accumulated rainfall and E.T was -3.7mm, i.e we lost 3.7mm from the soil over the month when you add up the accumulated rainfall and subtract the accumulated loss of moisture by E.T.

Let’s see how we look for 2018 at the same location ;

We sit at -311.8mm, so more than double the moisture deficit of 2017 for the same period and what’s more if we look at September 2018 in isolation, we continued to lose more moisture by E.T loss than we received by rainfall. Whereas in September 2017 the moisture deficit was -3.7mm, the figure for September 2018 was – 37.1mm, so we have continued drying down through September. So we are dry and strange as it seems, some areas will need irrigation to avoid going under moisture stress, particularly outfield areas where you may have overseeded.

That’s why we saw this information above from The National Drought Group (yes there is such a thing) declaring that the water supply situation in the southern half of the U.K is still fragile and good autumn / winter rainfall will be required to avoid water restrictions next year. I am grateful to Glenn Kirby of Syngenta for the link in one of his tweets…Read about it here

What of disease pressure through September ?

Well I think it has been a mixed picture with less disease pressure in general than last September and that’s down to humidity differences between September 2018 and September 2017, there is a caveat though. (more on that later)

If you look at the chart above which plots humidity across September 2018 and 2017, you’ll note in general a lower level for this year than last with shorter periods when it exceeded 90%, the critical value for disease pressure. Last September we had 6 peaks during the month when the humidity > 90% for extended periods of time vs. only 3 this September and the periods have been shorter. I have also highlighted the period at the end of September 2017 when we had a peak of humidity which carried into October, this generated high Microdochium pressure so we were already on the back foot from that perspective.

Now The Oxfordshire is a pretty open-aspect site, so in general humidity levels are lower than other sites which may be tree-lined. Data from my Netatmo comparing this year and last shows a different picture and that’s because my back garden sits in shade for a good % of the day and is less-affected by the wind.

So you can see in general much higher humidity levels because of the closed-aspect of the garden and it also shows the period at the end of September 2017 when we had extended periods of high humidity. In both locations, the end of September 2018 has shown lower humidity levels than the previous year so I think we are running into October in a better situation this year on the whole. Now for the north and west where you have received more rainfall this may not be the case but your ‘advantage’ is that you run cooler temperatures, particularly overnight, so the disease pressure tends to be earlier in the autumn rather than later.

Before I leave the chart above you’ll note that during this month there were some high humidity periods, notably around the 6th/7th, 20th, 21st and 23rd and these would have generated disease pressure on a shaded site.

That I think is the story of the autumn so far, lower disease pressure overall, but on shaded sites, it has still been significant.

Disease pressure looking forward

Looking at the stats for the coming week they illustrate my point above about the north-south divide with respect to temperatures and humidity. With low pressure influencing conditions in the north of Ireland, Scotland and northern England, it’ll be cooler and windier, so less risk of high overnight temperatures and high humidity and therefore disease.

It’s a different picture in the south as the winds are set to be lighter, particularly overnight and once we pick up the warmer air on Tuesday that’ll represent high disease pressure on Tuesday, Wednesday and Thursday nights. Much will depend on the intensity of wind on your site because if it continues to blow overnight then the humidity will be low, but if the winds are lighter and / or you have a sheltered site, I would expect higher localised humidity and consequently high disease pressure I am afraid.

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Ok that’s it for this week, I’m off on my travels to Switzerland and Germany, celebrating a 12th Birthday with Meteoblue in-between 🙂

There will be no blog next Monday because I’m off for the day for an event which I may or may not chat to you about in future blogs depending on how it goes of course.

All the best.

Mark Hunt