July 22nd

Hi All,

Firstly, a hearty congratulations to Ireland for producing one of the most popular Open winners for a long time, great to see a sportsman really enjoying the game and the moment.

I bet the number of internet searches for Co. Offaly went off the scale yesterday 🙂

Let’s hope the game of golf in Ireland benefits from this popular win…..

There was some pretty stormy weather around this weekend with a tornado reported in Manchester. We picked up nearly 12mm on Thursday night / Friday morning and all of that rain will be needed in the coming week because of the high temperatures that are predicted. Very welcome it was too apart from when I was fishing on Saturday and got dumped on. It’s pretty tricky trying to fish dry flies when it’s hammering it down !!

It isn’t just grass that will need a drink this week, spare a thought for your local bird and animal life. This little chap / chapess is the first Hedgepiglet born in my garden which currently has 3 Hedgehogs in residence, made my evening and hopefully more to come. I feed them on a mix of mealworms and Ark Hedgehog food and if I see young like this I put out some Lactol (Puppy milk) along with water just in case mum isn’t about to wean her offspring.

An interesting weather week coming up and quite a test for turf surfaces at the same time so without further ado I’ll move on….

General Weather Situation

So Monday sees the beginning of the heat build up with the wind swinging round to the south, ushering in that warm air. A definite case though of north-south divide because Scotland and Northern Ireland will be sitting under some heavy rain which will push eastwards through the course of the day possibly not reaching the far north and east of Scotland. Still warm under that rain though with high teens / low twenties expected. Further west and south it’s a pretty dry start for Ireland, England and Wales except for the possibility of some coastal showers across south-west Kerry and later in the day, across Connacht. For England, Ireland and Wales a dull start will soon give way to plenty of sunshine and in it the heat will soon ramp up with 24-26°C expected today. Strong to moderate southerly / south-westerly winds expected.

Onto Tuesday and after a warmish night, Tuesday looks to roll out pretty similar except the heat will be building even higher. So after the early morning cloud burns off we will see a day of sunshine and high temperatures with the likelihood that the 30°C mark will be reached across England and Wales. Ireland and Scotland won’t be that far behind though with mid to high twenties forecast. There will be a rain front sitting just off the west coast of Ireland, in fact I reckon the Mackerel fisherman lining up along the Cliffs of Moher will probably be able to see it but as continental high pressure builds, that’s where it’ll stay for the time-being. Winds will be lighter and from the south / south-east on Tuesday and there’s a suggestion of rain pushing into the west of Ireland and the U.K late on Tuesday night.

Mid-week and here the weather picture starts to get a bit fruity. I was smiling to myself last night as both the Countryfile and BBC Weather forecasters refused to put any detail and where and when the breakdown of weather will take place this week, so I’ll follow suit.

I remember this pic from May 2018 when we had a raft of thunderstorms vectoring along the M1 because of the heat build up from the concrete and probably stationary cars knowing the state of England’s motorways at present. So predicting where and when it will break down is really a job for you and your chosen rain radar sometime from Wednesday.

Currently the projection is for rain to push into Ireland and the west of England on Tuesday night and as that moist air hits the continental high pressure system and heat we will see it trigger off thunderstorms through early Wednesday morning initially across the western coastline of the U.K and extending from The South West right up to Scotland. Currently the overnight rain is projected not to affect the south-east and East Anglia but it’ll be hit and miss as explained above. So the start of Wednesday could be wet and thundery but through the morning the thunderstorms will abate and we will be in for another very hot day, maybe a little cooler on Wednesday because of the rain overnight. So touching 30°C again on Wednesday across England and Wales, a little cooler for Scotland and Ireland with low to mid-twenties respectively forecast. During the late afternoon / evening there’s a suggestion of more thunderstorms likely to pop up again. A very sticky night is projected for Wednesday so get them fans ready and have a cooling shower before trying to get some kip.

Onto Thursday and potentially the hottest day of the week with low thirties projected in the forecast. Overnight though we see the beginning of a change in the weather dynamic with rain pushing into the south-west and west of Ireland courtesy of an Atlantic low pressure system which is due to move the continental high pressure system away. So Thursday looks a potentially wet day for the west of Ireland and Irish Midlands as rain moves slowly across the country, dissipating as it does so. Leinster may stay pretty dry save for some showers later in the day. A dry start for the UK if a little duller than of late and the west will feel the influence of that Atlantic high first with cloud building and some showers likely to trigger off across Wales during the morning. So still a very hot day on Thursday with the likelihood of more cloud across the west and a thundery breakdown later in the day potentially. Depending on whether you get that breakdown you may be in for another warm and sticky night I’m afraid. During the day the wind will swing round to south-westerly and that’ll usher in cooler temperatures for the end of the week.

So Friday looks to be cooler with more cloud cover through the day and some showers across Ireland, The South West, possibly South Wales and the south coast of England, particularly later in the day. Still pleasant though with temperatures in the low twenties. Scotland looks to stay dry until the evening but that low pressure will push in more cloud cover to the west of the U.K and of course fresher air and cooler, welcome temperatures. The wind will be strong to moderate and from the south-west and a cooler night than of late likely with mid teen and not high teen temperatures.

The outlook for the weekend is unsettled, cooler than of late with low pressure close by the Irish coast so more in the way of cloud cover and showers for Ireland, Scotland, Wales and The South West. Not too bad the further east you go on Saturday with more spells of sunshine. Still a likelihood of showers though across Ireland, Scotland and the west of England / Wales. Sunday sees that low pressure move towards the south-west coast of England so more in the way of rain for the south of Ireland, south west and south coast of England. The rain is more likely to be across Ireland, the west / south west / north-west of England and west of Scotland. Temperature-wise – high teens to low twenties and winds strong to moderate from the south west / west.

Weather Outlook

Very much a case of north-south divide next week as low pressure looks to start the week off wet and windy across Ireland, Wales, the north / north-west of England and Scotland as low pressure pushes across the U.K. Tuesday could see some showers further south but sunshine and showers looks an apt description for most areas. Drier mid-week before a new low pressure system pushes in across Ireland, the north of England and Scotland bringing strong winds and plenty of rain on Thursday. The south of England looks to pick up the influence of high pressure so settled, drier and calmer winds but the rub will be where the dividing line actually ends up being somewhere across the U.K. At the moment there’s a good degree of uncertainty with most of the rain going west and north but that could change.

Agronomic Notes

Anthracnose

Late last week I tweeted about the possibility of Anthracnose over the coming weeks because of the critical combination of a projected high heat signature and humidity / rainfall over the coming week or so…In this blog I can put a bit more detail on it…

So up until now in most locations across the U.K and Ireland we haven’t had sufficient temperature and humidity for long enough to trigger aggressive Anthracnose. Generally speaking we need consecutive days of 25°C plus and humidity either at the same time or shortly afterwards. This humidity needs to be high enough to give extended periods of plant leaf wetness so dew formation and / or rainfall is ideal or not ideal depending on your perspective.

Now there may have been a meeting of the two in Scotland earlier this summer but since I don’t have access to temperature and humidity data on a regular basis from there  I can’t really comment.  You can see in the above graph that when we have had high temperatures during July, we haven’t had high humidity and you need the two to get this disease moving in its foliar blight form.

Looking at some different locations on Headland Weathercheck gives us a bit of an idea what to expect going forward this week……………..

To me Scotland and Ireland are very close to an Anthracnose signal with Wales and England pretty much clear in meeting the criteria for spore germination and development.

That doesn’t necessarily mean though that we will see Anthracnose on turf surfaces….

Anthracnose infection into the grass plant is a 3-stage process, the first relies on spore germination, then soon after the development of a specific structure on the plant leaf, crown, stem surface called an Appressorium. Think of this as a door through which the fungus enters the plant cells.

Here’s an excellent image by the ever-helpful Kate Entwistle (No ‘h’ you know)  which shows the Appressorium (black structures) and the primary hyphae emerging from them…

Image courtesy of Kate Entwistle

Once inside the plant the fungus doesn’t immediately go into necrotic mode (causing death of plant cells). Instead it can sit in a ‘resting phase’ referred to as a Biotroph. In this Biotrophic state it is undetectable by the plant itself and indeed may never move on from this stage. That is because it needs a secondary trigger and this is thought to be related to plant stress.

That’s when the climate and / or our cultural BMP’s (or more precisely a lack of one or more of them) come into play. I am convinced that in some years we meet the temperature criteria for Anthracnose  but don’t see disease because either we don’t get the necessary humidity / periods of plant leaf wetness for fungal and appressorium development and / or we don’t get sufficient stress to switch the fungus from Biotroph to Necrotroph.

Now here’s the second part of the Anthracnose story and again I’ll relate to the Meteoturf images above from different regions of the U.K and Ireland.

If you look at the projected Growth Potential (G.P) for the coming week in some of the locations we see a reduction through Tuesday to Thursday and in some we don’t.

Here’s the one for South Wales as an example…

The reduction in G.P suggests that we are reaching temperatures higher than the optimum for plant growth and so we see a reduction in growth as the grass plant goes into shut down mode in order to save water and conserve itself. Now different grass species have different ‘top out’ temperatures and I’d say Poa annua is the first to say “Be jaysus it’s a tad hot” at around 27°C, creeping bentgrass is a bit higher, maybe around 30°C (?)

So not only do we have a heat and humidity / rainfall signature in some locations this week, we also have a clear sign of plant stress as indicated by the decreasing G.P levels. That said in the Irish and Scottish locations we don’t….

So in some locations the trigger is clearly likely but does this mean we all have to run out and spray a preventative fungicide in the light of impending Anthracnose doom ?

No not really….

The importance of Best Management Practice and the development of Anthracnose

This disease more than Microdochium is significantly affected by good BMP’s and if these are in place then one can dramatically reduce the likelihood of this disease. Reduce but not remove though….

The most important contributory BMP is held to be nitrogen levels in the plant leaf with too-low an N level causing increased Anthracnose. The research by Rutgers University clearly highlighted the relationship between this disease and insufficient N levels in the grass leaf tissue…

Reproduced courtesy of Bruce Clarke, Rutgers University….

The above graphic shows how high levels of Anthracnose were present at low N plant leaf tissue levels but once you got to ≥ 3.6% plant leaf N, then the level of the disease dropped significantly. It is the strongest contributory BMP, full-stop. Research at Rutgers also highlighted a similar relationship with plant leaf K levels though the effect wasn’t as strong with ≥ 2.0% being the critical level here.

Now let’s just look at this with respect to the coming week….

We have some very high temperatures projected over a short period and we also have the prospect of some rainfall, possible thundery in nature. If we pump the grass plant full of N this week we will probably increase the risk of disease because too high an N level will mean the plant will require more water to produce more plant leaf tissue. That tissue will be succulent in nature with a thin epidermis (easy to penetrate by a fungus) and will show poor wear tolerance.

We may or may not also get an ‘N’ input courtesy of rainfall derived from thunderstorms so I wouldn’t be putting much if any N on this week but once we have cooled down I’d look to make sure my grass plat wasn’t ‘hanging’ on insufficient N, no way Jose….

I’d be prioritising stress management this week by ensuring I had applied a good quality biostimulant, maintaining sufficient but not excessive soil moisture and culturally I’m not planning anything to put the grass plant on the back foot. That means no deep lateral aeration, aggressive verticutting, brushing, etc. I’d also be keeping my cutting height and frequency sensible and since in some locations we have a projected reduction in growth, I’d try and miss a cut and replace it with a roll instead whilst we are in the high stress period.

There’s a crackingly useful link from Rutgers University detailing the research findings and BMP’s for this disease here

Caveat time…

Now as with anything in life there is a caveat to the above and that relates to whether I was managing a situation where I have either recurring Anthracnose or got hammered in the late summer / early autumn of 2018….

If this was the case then it is likely there will be a high level of localised spores present on some areas and so your chance of developing this disease is much higher. In this instance specifically I would be inclined to apply a preventative fungicide early next week and make sure I had the afore-mentioned BMP’s in place as well….

Not just Anthracnose…

With high temperatures, high humidity and potentially thundery weather / downpours I’d expect to see more in the way of Waitea Patch, Fairy Ring, Thatch Collapse, Red Thread, Etiolated Growth,  and may be a bit of Dollar Spot (though it is early yet) popping up this week and next…

Ok the publishing deadline beckons so that’s all for this week…

Enjoy the heat, but maybe not the sticky nights and I’ll catch you on the flip side 🙂

Mark Hunt

 

 

 

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