Monthly Archives: July 2019

July 15th

Hi All,

As my significant other reminded me yesterday, today is St Swithin’s Day, which we can think of as an early attempt at weather forecasting.

The ryhme goes “St. Swithin’s day if thou dost rain For forty days it will remain St. Swithin’s day if thou be fair For forty days ’twill rain nae mair

Well according to that we will have 40 days of fair, dry, warm and sometimes dull weather and no rain. Sadly or fortunately depending on your water situation, the rhyme will prove inaccurate this week / year as we have rain on the horizon at the end of this week and possibly next. We also picked up two nightly rainfall events here last week, each came out of nowhere and each gave us around 6mm. Marvelous.

Speaking of marvelous, I enjoyed a beautiful morning’s fly fishing the other day, notable for some feisty Trout that made me work hard with my left arm casting, (don’t ask) four low passes over the reservoir by a Spitfire that was obviously on a testing circuit, a low pass by another fantastic aviator, a Hobby, (Falcon) intent on catching an unsuspecting Swift, Swallow or House Martin and capped off by seeing an Osprey take a Trout right in front of me. Cracking. There’s something about the sound of a Merlin engine on full chat that gives me goose pimples. Never forgotten.

Being slightly patriotic (when it suits), I should mention what a great day it was for England yesterday in both the F1 and Cricket World Cup, both had their fair share of fortune for sure but just for once we won and that was brill. I don’t know what it is about the Kiwi’s but they represent their country brilliantly at all sports I watch and their team yesterday were a credit to their country. Fair play to everyone involved and to the game of cricket.

OK, without further ado, onto the weather as I have to see a man about a dog later…

General Weather Situation

Well the story for Monday is dry but a little dull to start off with as there’s no rain on the radar anywhere in the U.K and Ireland as I sit at this well-worn desk. So dry and dull for many and quite cool as well with temperatures in single figures last night. Through the morning the cloud will break and we will see some pleasantly warm sunshine. The east coast may hang onto that cloud all day as could some parts of North Wales and The North-West but other than that it should be a nice day. Light winds swinging round from the north to the south through the day and temperatures evenly distributed across the low twenties projected for the U.K and Ireland. Later in the day we may see cloud push in and bring the odd bit of mizzly, drizzle to the west coast of Ireland.

Overnight into Tuesday and that thickening cloud across Ireland may bring some light showers through the course of Tuesday morning. These will push eastwards. For the U.K, a similar start to Monday with plenty of cloud cover but this will soon burn off to give long spells of unbroken sunshine during which temperatures will quickly push up to surpass Monday’s, with low to mid-twenties very likely across the south of England, The Midlands and Wales. Scotland and Ireland will see more in the way of cloud and this will keep temperatures down into the high teens, low twenties. We will also see that rain pushing east across Ireland during the afternoon and consolidating into heavier showers across the east of Ireland and west of Scotland. These showers across Scotland will push inland through the afternoon and again consolidate over the north-east of Scotland.

Image courtesy of www.tropicaltidbits.com

Wednesday sees the beginning of the change to the weather this week as a transitional high pressure peak is punted politely out of the way by an incoming north-westerly, Atlantic high pressure system. (see image above) This low pressure system will push rain into the north-west of Ireland just in time for the Co. Sligo rush hour and through the course of Wednesday morning this rain will move south and east across Ireland. Further east across The Irish Sea we will get another day out of the high pressure peak so a repeat really of Tuesday for England and Wales at least with early cloud burning off to give us long spells of warm sunshine. Warm again with temperatures pushing up into the low to mid-twenties across England and Wales. Scotland will see that rain make landfall across the north-west around midday and this rain will then move slowly into central areas later in the day, pushing showers ahead of it. So a cooler day for Ireland and Scotland under that cloud and rain, expect high teen temperatures and a strengthening south-westerly / westerly wind veering north-west overnight.

Thursday sees that rain clear Ireland overnight, push into the western side of the U.K and stretch all the way from The South West up to Scotland. By dawn this rain front will have broken up into a belt of slow-moving showers arranged from The South West up through Wales across The Pennines and into The North East. Scotland should start dry on the west and in central areas but they’ll be rain across the east. Through the morning the belt of showers will move slowly eastwards clearing Scotland and pushing thick cloud ahead of them so a much duller start to the day for England and Wales. So a risk of showers for England and Wales through the morning on Thursday but these will disperse as we go through Thursday afternoon.  After a drier morning, Ireland, Northern Ireland and Scotland will see rain push into the north-east for the 2nd half of the day as that low swings in more unsettled weather. At this stage that rain looks to stay mainly confined to the north-west of Ireland, Northern Ireland and Scotland. England and Wales will see a day of sunshine and showers, cooler than of late with temperatures just nudging into the twenties. Ireland and Scotland with that thicker cloud will be more like mid to high teens so a little cool for this time of year. One of the reasons for that dip in temperatures will be a north-westerly wind which will blow fresh to moderate through the course of the day.

Closing out the week on Friday we see that first Atlantic low held in situ off the coast of Scotland but a new developing low will push in from the south-west and this will bring more southerly focused rain. From dawn this will already be across the south-west of Ireland, England and Scotland and through the morning it will push in to all western areas consolidating as it does. By Friday lunchtime that rain will straddle Ireland, Wales, the north west and north of England and Scotland but East Anglia, The South East and East Midlands may stay dry for a good bit longer with spells of sunshine for the east coast. By late afternoon Friday that low is centred over Ireland and so will push rain more eastwards across the southern half of the U.K, clearing Ireland as it does so. So a wet night for Wales, Scotland and England on Friday going into Saturday but Ireland should stay dry, though dull and cool. High teens likely for Friday for just about everyone, maybe nudging into the low twenties before the rain arrives for the east and south-east of England.

No surprise then that the outlook for the weekend starts unsettled with Saturday looking to start showery across central and eastern half of the U.K, with heavier rain for northern Scotland. Ireland should see the best of the weather as the thick cloud begins to lift giving some nice spells of sunshine. Through the course of Saturday those showers may linger across England, Scotland and Wales right through to early evening before the cloud breaks and we see some decent sunshine. Sunday looks a much nicer day for England, Scotland and Wales with early cloud breaking to give long spells of pleasant sunshine. Ireland on the other hand picks up the leading edge of another Atlantic low which will bring cloud and rain to the western half through Sunday. This rain will push eastwards through the course of Sunday. So dull cool and potentially wet for Ireland, but pleasant for the U.K with temperatures picking up into the low twenties on Sunday.

Image courtesy of tropicaltidbits.com

Weather Outlook

Hmmm, a tricky one to call because usually with low pressure pushing in from the west on Sunday that would make for an unsettled week, next week but I’m not so sure. So currently Monday does indeed look unsettled especially for the north and west with some wind and rain pushing showers through from early doors. Further south we could indeed see some of these showers push inland but as we go through Monday a continental high pressure is set to build and that may bring significant heat into the weather picture for next week.

The image above shows the projected hot air plume extending up from Africa for Wed 24th July potentially resulting in high temperatures for the U.K and Scandinavia next week.

So heat building from Monday through to Thursday but it isn’t going to be just dry and hot, I think we might be in for a humid one as well as there’s moisture lurking south of the U.K next week. At this stage it looks like Tuesday to Thursday will be warm / hot and dry before we start to see a cooling off later next week and rain push into the picture from Friday onwards, initially into Ireland but England and Wales later. With the threat of rain coming from the continent we can be certain of uncertainty about who and where will get it and also that Scotland and the north will see less of it. It wouldn’t surprise me if we don’t see this weather forecast change around a bit next week.

Agronomic Notes

Soil Moisture Status

I thought it would be interesting now we are theoretically half way through summer (June to August in my books) to see how 2019 and 2018 compare from a soil moisture status perspective. Now I appreciate this isn’t for everyone, especially where you’ve had plenty of rain but as we saw with last months stats, we have been dry in some locations and in July for places like The Oxfordshire, they’ve had no rain at all.

It is slightly unrealistic as it takes no account of what happened soil moisture-wise in May or before that but for me it gives an indication of how much plant stress we are facing and your likely water usage so far…

So how is summer 2019 shaping up vs. 2018 ?

The graphs above highlight the two very different patterns of soil moisture deficit and how crucial that wet week in June this year was in terms of recharging the soil on unirrigated areas.

In 2018 you can see how we basically flat-lined E.T and therefore moisture deficit right from the 1st of June with no rainfall at this location through the 6-week period. In 2019 we began the same pattern in early June but the week of rain pushed us into a soil moisture surplus that prevented us going into a deficit until the end of June, it effectively brought us a month less plant stress and water usage. From the 1st of July though we have followed a similar pattern in 2019 vs. 2018 with consistently high E.T and no rainfall.

Comparing the first 14 days of July, our E.T loss this year has been 47.4mm vs. 63mm in 2018, so still pretty significant and that’s why we are seeing unirrigated areas going under stress. Hopefully the projected rainfall at the end of this week will help matters a little.

That said however you dress it up we are in a better situation than last year.

Disease Activity

Watching the cricket yesterday it was impossible not to notice the large amount of Fairy Rings on the pitch. This isn’t a criticism it’s more an indication of the type of summer we are having in 2019 vs. previous one’s. The wet spell in June brought us humidity and that’s something that didn’t feature highly last summer, hence the higher disease activity associated with June 2019 and to a slightly lesser degree, July 2019.

I charted out my Netatmo weather station stats from June 2019 vs. 2018 to see how the two months compared from a humidity perspective ;

OK, now my weather station is in a sheltered location so tends to run higher humidities than a more open location but the difference between this June and last June is clear to see. In June 2018 we never once topped 90% average daily humidity, whereas in June 2019 we have topped out at 100% daily humidity for an extended period, particularly when we got that rain between the 8th and 16th of June.

So that’s why we have seen plenty of Fairy Ring, Waitea Patch and Red Thread activity as these diseases just love humidity. Now it’s worth bearing in mind that although Fairy Rings are more aesthetic than disruptive they do have a dark side to them in that they can turn the soil profile hydrophobic and stress the grass plant. There’s also a suggestion that they can in certain instances release ammonia gas (which is toxic to plant root systems) and thereby kill off the grass plant.

It very much depends on the type of Fairy Ring you have as these moisture level samples show below….

Bearing that in mind and the potential prospect of some high temperatures this week and next, it’s worth keeping an eye on them from a hydrophobicity perspective.

On another disease-related note, I saw my first Anthracnose last week, a little bit of basal rot on a wear pathway at the edge of a green, nothing more than that but I am wondering if this week’s high temperatures followed by rainfall will be a trigger event. The same could easily be said for next week with likely even higher temperatures for a period if the hot plume weather pattern takes place.

Seedheads

2019 must surely be the longest seedhead flush I can remember at 10 weeks and counting. I think the wet period in June almost reset the Poa and so we saw a big flush of seedheads after the rain event. If that’s correct, the level of seedheads should begin to decline over the next 7-10 days naturally without cultural assistance 🙂

OK that’s it for me this week, enjoy the heat and hope for the rain afterwards 🙂

All the best.

Mark Hunt

 

 

8th July

 

Hi All,

Already the 1st week of July is behind us and except for the odd heat plume / transitional peak pattern in the jet stream we have been spared a repeat of last summer’s weather. Opinions I’m sure are divided on which kind of summer you prefer but from a grass perspective, I’d take this one any day of the week.

I think back in May I said I had a hunch that no one weather pattern would dominate this summer and so far, so good. Out walking yesterday the temperature at 21°C was ‘just right’, kind of like if you could set the thermometer for the temperature you’d want, that would be it thanks, just nice 🙂

Lots of Butterflies on the wing yesterday, I think insects in general must be having a better year and with some farmers leaving margins on the edge of fields to go wild, it can only get better. At one point yesterday on my walk I could hear nothing but the sound of Skylarks, simply lovely.

So let’s see what we have in store this week, a bit of rain maybe for some 🙂

General Weather Situation

OK, so we start Monday with some rain already over Connacht, Leinster and north Munster with the far south missing out at present. Over the Irish Sea we currently have a dry, if a little cool and dull start to the week.  The far south-east and south of England though will probably be seeing more in the way of sunshine today but overall it is a dull and cloudy day for the U.K with rain pushing into the north-west of England / North Wales / west of Scotland later this morning / through the afternoon. Pleasantly warm with temperatures in the low twenties for the south of England and just a degree or two down on that for The Midlands, Wales, north of England and Ireland. That rain over Ireland should clear for the 2nd half of the day as it moves into Scotland and The North West. Here it will be a little cooler with that thicker cloud base and rain moving in later in the day. A strong to moderate south-westerly / southerly wind will keep temperatures pleasant.

Onto Tuesday and that rain from Monday will start Tuesday centred over Scotland and The Borders with some of it pushing down into northern England from the off. Ireland looks to start dry and dull with that thick cloud base extending across The Irish Sea into Wales and England. So a dull start for us all on Tuesday. Maybe some of those showers will extend down into the north Midlands but that looks as far as they’ll reach. As we go through the morning that rain retreats from the north of England but I’d still expect plenty of showers across The Borders, Northern Ireland and Scotland through the course of Tuesday. Further south and west we look to have a dry, dull day with pleasant temperatures and a chance of sunshine across The South West. Temperature-wise, similar to Monday with 18-22°C  likely  with a moderating westerly wind veering north-westerly later in the day.

Wednesday looks potentially wet from the off with rain into Northern Ireland and western Scotland at dawn. This is projected to push down into northern England through the morning into central and eastern parts as we progress through the afternoon, breaking up into showers as it does so. From midday we can also expect some rain pushing into the west coast of Ireland but at this stage it appears to make slow progress inland during the afternoon. By tea time the rain across the U.K will be affecting most areas but the west side of the country and Wales may be spared. Scotland looks to have a wet day for sure with the rain moving south and north as we go through the afternoon. Needless to say it may not reach the far south of England / Home Counties so here expect a warm and dry day with temperatures pushing up into the low to mid-twenties. Elsewhere under that cloud cover and rain, temperatures will range from high teens (Ireland / Scotland) to low twenties for south of England. Winds will be light to moderate westerly veering south-westerly through the day.

Onto Thursday, my how the time flies, and overnight that rain is projected to affect the eastern coastline of the U.K and then push down into The South East. Along with this southerly rain we will also see rain showers continue to affect the west coast of Ireland and the north-west / west coast of Scotland. Through the course of Thursday morning we will see that Irish rain move eastwards across the country together with that Scottish rain moving southerly. Further south we will see more in the way of sunshine but this rise in heat will trigger plenty of showers across northern England, The Midlands and southern England. Again the projected emphasis for these showers is central and easterly rather than western coasts and Wales.  By late afternoon that rain will have cleared the west coast of Ireland but still be heavy across the north and east. Likewise we will see more showers spread liberally from Scotland down the central and eastern side of the U.K and possibly some of these will be thundery in nature. Winds will be light to moderate and from the north-west.

Closing out the week on Friday and we start off with a dry, dull picture across the U.K and Ireland. Largely dry but it won’t stay that way for long. Showers and longer spells of rain will kick off across Scotland, the north of England and these will again extend down the central and eastern side of the country through The Midlands and into the south-east of England. So again the western side of England, The South West and Wales appears to miss the worst of the weather though North Wales may cop some showers. Again I think they’ll be potential for some thunder among these showers. So a sunshine and showers day for many on Friday but temperature-wise we will still be in the high teens to low twenties for most areas, maybe warmer in the south of England with less cloud. The wind will strengthen on Friday to a more strong to moderate north-westerly.

So how does the weekend look, will I watch the boat fill up with rain as per last Saturday or be slapping on the sun cream ?

Well not bad really and kind of similar to last weekend.

Saturday looks to start off dull but dry pretty much everywhere and as we go through the morning that cloud cover will break up to give some nice spells of sunshine. There’s a risk of this warmth triggering off some thundery downpours in the afternoon over central and eastern counties of England, northern England and Scotland but other than that we should be dry and warm. Temperature-wise, similar to Friday with high teens to low twenties the order of the day and lighter winds still from the north. Sunday looks drier and warmer with the only blot on the landscape being a raft of showers set to push into the west coast of Ireland later on in the day. Opinions are a bit divided but we look to pick up higher temperatures across the west of the U.K and across Ireland this weekend with slightly cooler and more humid conditions across the east.

Weather Outlook

Well next week looks like a bit of a split picture across the U.K and Ireland because we have a warm high pressure south of us and Atlantic low pressure systems feeding in. So I think we can expect a sunshine and showers type of week with Ireland, the west and north picking up the majority of any rainfall, especially early in the week before more settled conditions establish mid-week for all of us. Come the end of the week we look to have a more southerly-based low pressure pushing in stronger south westerly winds and cooler, more unsettled conditions but this is a way off yet and will no doubt change. Again no one weather system dominating the day for summer 2019.

Agronomic Notes

OK, didn’t do it last week for various reasons but let’s look back at June 2019 from around the U.K and Ireland.

GDD Summary – Location – The Oxfordshire

From a GDD perspective, June 2019 was pretty average really and bore remarkable similarity to 2016, 2014, 2010. From a stats perspective it was 14% cooler than 2018.

Now we know GDD doesn’t tell the whole story, because other factors can and will affect grass growth, with moisture specifically in terms of Poa annua being the limiting factor.

Cumulative year-to-date, 2019 from a GDD perspective is tracking on the low side after the cooler than previous years June. I have charted out the above from 2013 to 2019, Jan – June so you can see how 2019 is shaping up so far…

So you can see a kind of middle of the road year from a GDD point of view with 2017 remaining by far the highest year we have tracked.

GDD & Rainfall – June 2019 – U.K Locations

Of course the story of June 2019 was not really the average temperature, it was the fact that we got a good dollop of rainfall, particularly across the south and east of the U.K and for me it saved the day from a turfgrass maintenance perspective 🙂 Lots of areas were droughting out again and spring and autumn overseeding efforts were looking borderline.

It isn’t very often that Birmingham comes out top of the pops when we talk about rainfall but this location recorded 160.1mm of rain in the month of June, just over 6″, but this was by no means the wettest place in the U.K this June. East Anglia and particularly Lincolnshire were one of the wettest regions with 120-150mm of rain falling over a 3-day period from the 10th to the 12th of June. Some golf course locations reported 100mm of rainfall in a day. GDD-wise, we were pretty consistent but in northern locations, still cool with Fife sitting 25% lower than a typical Midland location.

Here’s how June shaped up from a daily perspective at the Birmingham location…

You can clearly see the influence of the trough pattern in the jet stream giving some very high daily rainfall totals in the mid-part of June 2019 and conversely at the end of June we saw a transitional peak pattern when warm air pushed up from Africa and we hit over 30°C with no rainfall.

GDD & Rainfall – June 2019 – Irish Locations

You can see similar consistency in the Irish picture from a GDD perspective with the east side of Ireland cooler and wetter than the west, not the normal weather picture for Ireland but the trough pattern that affected the U.K pushed cooler and wetter weather into the eastern side of Ireland. It isn’t often that Valentia comes out bottom of the Irish rainfall stats, gez you lads must have thought that the world was ending in Kerry being so dry 🙂 (I bet it was lovely in the west of Ireland in June)

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In northern and western locations though it has been on the cool side, an almost waiting for summer to start scenario.

You can see the difference in the graph below for Birmingham and Johnstown Castle, Wexford comparing Daily Growth Potential ;

In common with April and May this year when we have had heat we haven’t had moisture and vice-versa and this has led to Poa annua in particular struggling to produce consistent growth through the spring and early summer.

To further complicate matters, that spike of rainfall in mid-June kicked Poa annua into seedhead mode again at just the time we would normally expect seedhead production to be on the wane. Looking at some surfaces last week I could see far less seedheads on the more open situation greens which were growing better and so had reached the end of seedhead production earlier. So I do think we are just about there from the end of the seedhead flush perspective but it has been a longer period of seedhead production in 2019 because of the dry spring and then wet June. This has affected putting green consistency.

Looking ahead…

The coming week is for me an alright sort of week really with good temperatures allowing consistent growth and the possibility of some moisture to help things along because here in sunny Market Harborough we have been dry now for a couple of weeks and missed the showers on Saturday.

Not only is the growth outlook good but the projected E.T total for the week at 16mm moisture loss is much lower than we would experience in a hot period of weather (50% lower typically) so not too stressy for the grass plant for The Midlands anyway.

Further south with their higher temperatures and more sustained sunshine you can see the E.T rate is appreciably higher with 24mm moisture loss projected over the next 7 days.

Bottom line –  keep an eye on soil moisture levels this week lads and lasses down south…

Disease-wise I don’t expect too much to come out of the woodwork this week because humidity won’t be high for sustained periods across the south of England. For Ireland and Scotland though with more rainfall and a wetter plant leaf, you may see some summer Microdochium come to the fore.

Ok that’s it for this week, All the best…

Mark Hunt

 

 

 

 

 

 

July 1st

Hi All,

Bit of an abridged blog this week with back to normal service next week when I’ll do a monthly summary of June 2019, an interesting month in many ways, so hopefully you’ll bear with me…

What a scorcher Saturday was and with that wind, a pretty high E.T day to boot as well, we measured 5.73mm E.T loss on the weather station at The Oxfordshire (more on that later)

So for this week’s blog  I’m going to do a summary of the week’s weather, rather than drill down into individual days and actually we have a pretty stable weather picture so that kind of works.

Before I do I thought it was interesting to see a snapshot of last weekend, this week and next weekend when you look at it from a temperature and jet stream position perspective…

Thanks to Tropical Tidbits.com for use of the images….

Starting from the top we see the hot air plume as the jet stream forms a peak pattern and pulls warm air up from Africa. This resulted in our hottest day of the year so far and record temperatures in many countries in mainland Europe. This week we are seeing the weather settle down as high pressure asserts itself and we build some gentle heat compared to last weekend. Finishing off with the projection for next Sunday and you can see a trough pattern developing in the jet stream from the east (which is weird) and set to bring cooler, duller weather and some rainfall most likely…

General Weather Situation

So with high pressure in charge this week it’s going to mean pretty consistent conditions with some rain showers around today over Northern Ireland, Western Scotland and northern England. We will have a pretty strong north-west wind in place today and that’ll keep things on the cool side with mid to high teen temperatures likely. Cloud cover will be a feature of this week and particularly along the eastern coastline of the U.K. Tuesday looks a better day with a gentler north-westerly wind, pretty much dry everywhere across the U.K & Ireland except for some rain lingering over the far north-west of Scotland. Temperature-wise I’d expect mid to high teens with the cooler temperatures over Scotland and the warmest across the west and South Wales. Wednesday continues this pattern, bright at first but cloud soon coming in from the east across central areas of the U.K. Cloudy, dull but dry for Ireland as well. Wednesday looks a change day for the wind where we see it drop back in strength and swing round to the north-east / east. Lighter winds will mean a gentle hike in temperatures into the low twenties for the south of England, Wales and Midlands. Ireland and Scotland will still keep that cloud cover although Scotland should enjoy a better 2nd half of the day as the sun breaks through so a couple of degrees down on the temperature here, but dry. A similar forecast for Thursday with the exception of some rain due into the north-west of Scotland and likely to run along The Moray Firth into the north-east of Scotland as well. A much brighter day on Thursday with plenty of sunshine for England, Ireland and Wales and reasonable temperatures in the high teens to low twenties. Light winds as well as it starts to swing back to north-westerly through the day depending on your location. Closing out the week on Friday that rain over north-west Scotland clears through the morning only to re-appear as we go through the early afternoon. Elsewhere remaining dry but Ireland looks to stay cool and dull with some thick cloud pushing in from The Atlantic. Not so for England and Wales with long spells of unbroken sunshine and likely to be the warmest day of the week so far with temperatures pushing up into the low to mid-twenties in most areas. A strong to moderate north-west wind is expected to close out the week so a high E.T day no doubt.

With low pressure pushing in from the north it is no surprise that we have a north-south divide for next Saturday with the south of England hot and sunny with potential temperatures in the mid to high twenties. The same for Wales as well but as we move further north and east we pick up cloud cover and the cooling effects of an easterly wind and The North Sea to keep temperatures in the high teens, maybe low twenties. For Ireland and Scotland, not a bad Saturday with some good spells of sunshine and temperatures up in the high teens and low twenties. Sunday sees more in the way of cloud cover and a developing easterly wind so that’ll mean a cooler day for areas affected by the cloud cover with mid to high teens likely from The Midlands north. Further south and west you should still keep temperatures up in the high teens and low twenties for the west of England, Wales and Ireland.

Weather Outlook

An interesting one next week as we see a continental low pressure (strange for the summer?) out to the east of us and high pressure to the west. Usually it is the other way round. So as we go into next week expect a cooler northerly wind with some showers along eastern coasts through Monday and Tuesday  but drier, brighter and warmer towards the west. By Wednesday the high pressure should be keeping the cooler, more unsettled air to the east of us so drier for Wednesday before an Atlantic low pressure system is projected to usher the high pressure out-of-the-way and introduce cooler and wetter weather for the end of next week / next weekend. Temperature-wise, similar to this week really so high teens and low twenties by mid-week I reckon.

Agronomic Notes

A little look at last week….

The top graph is fairly self-explanatory as you can see we ran some pretty high humidity through the night last week after the rainfall on Monday and Tuesday. That heat on Saturday came late in the day and lasted right through into the evening with some locations still at > 25°C after 9 p.m.

The bottom graph shows the respective rainfall and E.T levels for each day and a running total of soil moisture deficit. Now of course your site will be different, you may be more sheltered than The Oxfordshire and consequently run lower daily E.T totals, you may have had more rain as well. What is interesting is that despite 6mm of rain on Monday / Tuesday, they were already running into moisture deficit by 10.00 a.m on Thursday morning because the daily E.T levels were so high. By Sunday evening they were at -19.63mm moisture deficit and with the dry and sometimes windy outlook this week, that deficit is set to grow.

So if you think you dried out quickly last week that’s why and what’s more is you’ll continue on this moisture deficit curve this week with very little rain forecast and some high winds. Meteoturf is predicting 30mm E.T loss over the next 7 days for the south of England which is similar to last week so keep an eye on things soil moisture-wise because the dry-down will continue this week.

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Disease activity

As discussed last week, with high moisture and high humidity, just about everything comes out of the woodwork from a disease perspective. Locations that picked up high rainfall over the last fortnight may have seen Waitea Patch on some greens. (above)

Although it resembles Superficial Fairy Ring, I think it is more vivid yellow in colour and tends to favour wetter areas on greens. Ordinarily it fades as quickly as it appears and doesn’t really affect the putting surface so I wouldn’t class it as public enemy no.1 in our climate.

Anthracnose Trigger ????

I’ve had quite a bit of correspondence about the likelihood of Anthracnose as we move into July and whether last week’s temperatures were enough to trigger the germination of spores and subsequent development of the disease. There’s no simple answer here and it really comes down to your site specifics in terms of critically both temperature and humidity, because it’s the combination of both that leads to disease development.

Take summer 2018 for example, sky high temperatures with consistent Anthracnose triggers / high stress and although we did indeed see some disease development, it was nowhere as bad as 2014 / 2016. The majority of Anthracnose we did see was late in the season, from September onwards…

So why wasn’t summer 2018 a high Anthracnose season ?

In my mind it was because of the lack of rainfall and therefore humidity which characterised last summer and thereby prevented mycelium development. (Anthracnose like most diseases is greatly encouraged by periods of plant leaf wetness)

So was last week’s weather a viable Anthracnose trigger ?

Well the conventional wisdom is that you need 3 days of ≥ 25°C for spore germination and then in my mind this needs to be followed by an extended period of plant leaf wetness for the fungal mycelium to develop on the leaf / crown of Poa annua. If you look at the map I think the only area that may have hit both criteria is Scotland because some areas there have had rainfall following the heat of the last week. That said it wouldn’t go down in my books as the strongest of Anthracnose signals.

The other thing is bear in mind with this disease is that the effect of having a good IPM program in place is much more significant. I’ve referenced it before but Bruce Clarke’s work at Rutgers pinpoints very specific IPM factors that greatly influence this disease regardless of fungicide applications. You can read about them here and here

By far the most critical factor in preventing this disease becoming your worst summer nightmare is plant health and specifically leaf tissue levels of nitrogen and potassium. Rutgers recommend keeping the plant leaf tissue N and K levels above 3.6% and 2.0% respectively which in my books is normal nutrition, nothing excessive and certainly not high enough to compromise greens speed. (Especially with good PGR usage)

The only time I see nutrition contribute to Anthracnose is when someone is on a “Let’s see how low I can go on my N” crusade and then gets hit and spends the rest of the summer chucking on N and seed to fill in the damage. It simply doesn’t make any sense to me why we still go down this route and as for the “It gets rid of my Poa annua and does me a favour” line then of course yes it does (temporarily) but what comes back in the voids that are left ? Poa annua and not your fine-leaved, perennial biotype, you’ll get the coarser, annual biotype that’ll stand out nicely for the next couple of years to remind you as it spends most of the year seeding 🙁

A bit harsh maybe but the number one lesson with Anthracnose is that most of the time it can be largely prevented by good non-pesticidal IPM,

OK, off my soapbox, have a good week with a reasonably stable forecast 🙂

All the best…

Mark Hunt