November 6th

171106_gfs_pres_500p_loop_eur

Hi All,

Welcome to the first blog of November and for the 2nd Monday in a row we start with a hard, penetrating frost down to -2.5°C here last night, that’s a pretty chilly one for the start of November.

061117frost

Trust me we need it because currently we are way higher than we should be for the start of November in terms of air and particularly soil temperature, something I don’t talk alot about really. Normally for the start of November we’d be down at 6-7°C soil temperature, but this year we were in double figures. (though after today’s frost we have dropped soil temperature significantly)

I know some of the reservoirs I fish that their water temperature is usually down at a similar figure but at the weekend they were sitting at 13°C and with very little water in them as well.  After a very dry October here in The Midlands, I can’t see us catching up any time soon in November though there will be some rain early on this week. Now we all know Mother Nature has a habit of balancing things up year on year, but if it doesn’t, we will have water restrictions next year.

General Weather Situation

So we start the week, cold, dry and frosty with high pressure extending a welcome hand to us, but this will soon be knocked aside by a northerly low pressure pushing in from the North Atlantic so we’ll see change first over Scotland and north west Ireland where rain will push in from the start of the morning rush hour and move inland. A real north / south – west / east split as that low pressure pushes in mild air from the south west for Ireland and Scotland whereas we will remain cold with light northerly winds for the rest of the U.K. By lunchtime Monday that rain is covering Scotland and moving down to The Borders and at the same time pushing into the west of Ireland. For the afternoon, the south and central regions of the U.K will have a dry, cold, but lovely winters day, whereas for Wales and The South West, we will see cloud building from the west. By dusk that slow-moving rain front is intensifying across the west of Ireland so a pretty wet end to the day for Connacht I’d say and we will also see that rain into Wales and moving eastwards slowly. Temperature-wise 7-8°C for central U.K and a milder 11-13°C for Scotland and Ireland.

Overnight into Tuesday and that rain looks set to have cleared Ireland and the west coast of Scotland by dawn though amounts will be heavy overnight for Munster and Leinster. The band of rain will now be sitting from Edinburgh and extending down through northern England, across Wales and The South West and I’d expect amounts to be heavy in some areas, particularly The North West which has had a clattering lately, sorry lads. East and south of this rain we will see a much cloudier, dull start as that rain pushes cloud before it. Through the course of Tuesday this band of rain moves really slowly and that means amounts that fall may be high in some locations. By lunchtime it should have cleared Scotland completely and most of Wales, leaving England to pick up the rain for the 2nd half of Tuesday. I should add after a wet Monday, Ireland and the west of Scotland looks to have a much drier, sunnier day on Tuesday. So by dusk we see that rain band sitting over the east of the U.K in a line drawn from Newcastle down to The Isle of Wight. We will then see a lighter band of rain push into the west of Ireland. So a kind of role reversal on Tuesday in terms of temperature, with Scotland and Ireland, cold and dry, sitting at 6-8°C and the rest of the U.K milder under that cloud and rain, just nudging into double figures on a strong southerly wind.

Wednesday sees that rain clearing the east of the U.K overnight so we start all areas with hazy sunshine and dry. This isn’t to last for the west of Ireland where a new rain front pushes in during Wednesday morning and moves slowly east, across country. For the U.K, we look to have a cool, dry and settled day on Wednesday with the east coast possibly enjoying most of the sunshine before cloud moves in from the west. Winds will be light to moderate and from the north west and that’s what will peg back temperatures to high single figures for the U.K, but milder across Ireland with that rain and cloud cover. As we progress through Wednesday evening we will see rain push into north west Scotland and move eastwards.

Onto Thursday and that rain across Ireland and Scotland has cleared across to the west of the U.K and Wales, fizzling out somewhat as it does so into a band of thick cloud that may bring light rain first off as it moves across the U.K. Scotland looks to start dry but Ireland has a cloud mass sitting right over it, so dull, dreary and damp I’m afraid for you guys. So a dull day for the west on Thursday with some rain pushing into north west Scotland for the 2nd half of the day clearing Ireland as it does so. There’s maybe a chance to see some hazy sunshine for the 2nd half of the day across The Midlands and south of England and with lightening north westerly winds, you may just see the temperature nudge up into double figures (gosh golly). For Ireland and the west of the U.K, including Wales, that cloud cover will bring with it milder temperatures, so here low teens are expected, the same for Scotland.

Closing out the week and on Friday we see high pressure try to push in from The Atlantic, but it’ll butt up against a continental low pressure at the weekend, more on this later. So overnight we see that low stubbornly influencing the weather across the west and north with rain pushing into Ireland and also Scotland. By mid-morning it’ll be into Wales and the north of England, but lightening as it moves south. Central and southern U.K will start dry, possibly bright but it won’t be long before thick cloud cover pushes south for the 2nd half of the day bringing rain to Wales, the north of England and maybe The Midlands after dusk. So a better 2nd half of the day than the first for Ireland and Scotland and vice-versa for Wales and England.

Looking at the weekend and it’s a tricky picture to forecast because of the relative projected position of that Atlantic high and continental low. My take on the weekend is that it will be cool and unsettled with rain pushing down on an initially westertly wind in the west, but an increasingly cool, north westerly wind for the U.K pushing cloud and some rain across on Saturday. Sunday could be a cool, calmer and drier day with high pressure pushing that low eastwards so a more settled picture possibly with less risk of rain, but plenty of cloud around.

Weather Outlook

So next week looks like high pressure will push in slowly from The Atlantic though we will feel its influence first on Sunday possibly. So I’m thinking that next week looks by and large, dry, cool but possibly dull and foggy with very little wind. The first part of the week promises to be milder with a westerly air flow but as we pass mid-week I think this will turn more northerly and chillier. There will be some rain around but I think it’ll mainly be for the far north west of Scotland as a low passes by early in the week.

Agronomic Notes

Since it is the first blog of the month, I will take us through some pretty interesting GDD / G.P information and then drill down further into the detail to look at why October 2017 was such a brutal disease month for many and how it differed from 2016 and the like.

Again I’d like to take this opportunity to say thanks to everyone for contributing information, without it I couldn’t easily do this.

U.K GDD Information – Location – The Oxfordshire

GDDmonthlycomparisonJantoDec2010to2017image

So looking at the monthly totals we see October 2017 came in as the warmest October we have recorded since we started this process back in 2010.

It is however with comparison against 2016 though that we truly see how warm this October really was.

So October 2017 came in with a total GDD of 228, compared to October 2016, which came in at 134.5. That’s just under 70% warmer than last year from a GDD-perspective and that’s the first clue as to why this October was such a tricky one to manage disease-wise. It should also give us a clue into respective growth levels, disease severity and ultimately fungicide performance, more on this later.

GDDmonthlycumulativeJantoDec2010to2017image

Cumulatively y.t.d we signed off the end of October with a total GDD of 2015.3, that’s the first time we have ever reached the 2,000 mark for a year and we still have two months to go !

Whichever way you dress it up, for this location it’ll be the warmest year ever and by some margin.

This is why I do this, month in and month out, because I believe these stats (which enable us to measure potential grass growth and compare them with prior years) are vital not only to looking back at our year but also they will ultimately help us to plan ahead.

October 2017 – GDD and Rainfall Stats – UK Locations

OctGDDRainfallUK

Quite a lot of variability in the GDD and rainfall stats for October, but particularly in the latter with Northampton in The Midlands coming in as the driest location at 9.3mm and Manchester just pipping Okehampton for the wettest, at 93.7mm, in other words 10 x the rainfall from one location to the other. When you look at The North West’s weather in October, you’ll see that not only did they have a wet month, but very few drying days in-between, with only 8 days out of 31 without rain.

SeptOctCompUKGDD

Thame and Cardiff clocked in as the warmest locations with GDD totals > 220 and interestingly very similar to Septembers total. That was indeed a pattern in general with October returning very similar GDD totals to September in a number of locations.

October 2017 – GDD and Rainfall Stats – Irish Locations

OctGDDRainfallIreland

For Ireland we again see that rainfall pattern split between the west and the east and indeed the south and the east. Not surprisingly for anyone that travels to that neck of the woods, Valentia came in both warmest and wettest with 151mm of rain. Contrast that with Dublin where the weather station at Casement recorded 46.3mm, roughly 1/3. We can also see the difference being close to the sea makes in terms of milder weather with a total GDD for the month of October of 160 at Casement, but 196 just a few miles east on the coast at Killiney.

Looking at a comparison of September 2017 vs. October 2017, the pattern is more normal with a 15-20% reduction for October vs. September. If I compare locations between Ireland and the U.K, we can see that we are on average 20-25% warmer this side of the Irish Sea, not an advantage though in October because that warmth drives grass growth and disease and it is this combination that makes life so difficult at times.

October 2017 – Detailed Analysis

Oct201716CompUKGP

Above is a trace of the daily Growth Potential shown in red for 2017 and green for 2016. I think you can clearly see the difference in the two graphs !

If I add up the respective Growth Potential figures for October 2016 and 2017 for this location, there is a 73% difference.

Why is this significant ?

Fungicide Efficacy and Longevity

Oct201716CompUKGPCum

So here’s the same graph as above but expressing the data cumulatively.

Again you can clearly see the difference between this year and last, well I hope you can anyway.

Now let’s consider the following scenario ;

In both years we make a systemic fungicide application on the 1st of October and for the sake of this example, let’s just say that we know that a typical systemic fungicide will last for a total Growth Potential of 10.0, it’s a nice easy round number for me to work with on a Monday morning :)

Let’s see how long the applications last when we compare 2017 vs. 2016 ?

Oct201716CompUKGPCumfung

So in October 2016, that systemic fungicide would have got to the 26th day before it was grown out of the grass sward, whereas in October 2017 it would have got to the 14th day.

So there it is in back and white.

Why didn’t your fungicide regime / strategy perform as well as it did in 2016 ?

Quite simply because it was grown out in roughly half the time of a ‘normal’ October, but that’s not all…

Oct2017CompUKGP

The second part of the equation is the severity / activity of the disease.

If we look at the chart above you can see that we had a lot of periods during October when we were nearly maxed out in terms of the growth potential of grass. There is clearly a correlation between the growth potential of grass and the growth potential of a pathogenic fungi, although they both rely on other factors as well to grow.

So the warmer it is, the faster Microdochium nivale will reproduce as a population and the harder it is to stop this happening with a fungicide. For much of October we experienced Microdochium nivale at its most severest because we had the double whammy of high humidity (as I have been showing through this month in my blog’s and high air temperature)

In summary, fungicide performance in October 2017 was compromised by a very fast ‘grow out rate’ and very aggressive disease population growth, which in some cases out-stripped the ability of the fungicide to hold it back.

Looking ahead….

With milder weather this week for the west and some moisture I would still expect disease pressure to be moderate – high across Ireland in particular because of the milder night time temperatures. For the U.K, there’s currently no sign of a re-occurence of high humidity / high night time temperatures in the forecast, so we can relax a little on this front.

Nov617

You can clearly see this in the growth outlook for the next 7 days with the daily G.P rarely exceeding the 0.25 mark. Compare that with a month ago !

Ok that’s it for this week, hopefully you’ll have found that interesting as you digest all that info over a cuppa :)

All the best..

Mark Hunt

 

 

4 thoughts on “November 6th

  1. Graham Pickin

    Thank you Mark for the quick reply, this time next year will be a tester I think with the imminent loss of iprodione.
    Thank god for 20-20-30
    Regards Graham

    Reply
  2. Graham Pickin

    Thank you Mark,
    This blog entry totally explains my predicament so cheers for that.
    Just wondering could growth retardants play a role here in terms of fungicide efficacy, especially at time such as these? Or is it a mystic meg moment.
    Kindest regards
    Graham Pickin

    Reply
    1. mark.hunt Post author

      Hi Graham,

      Definitely not a mystic meg moment at all and one area I’ve considered many times of late.

      Unfortunately this year all my efforts have been focussed on a couple of new products and the new fungicide formulations that have entered the market but next year I’d like to do some proper trialling with PGR and then fungicide applications to determine if this is a possible way forward. I guess one of the salient points is that to really hold back growth and thus gain longevity you’d need to go higher than labelled rate on fine turf. In principle it should work Graham, may be worth a trial even now on an area ?

      Reply

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