17th August

Hi All,

Well quite a change over the last week in the weather !

Thankfully gone are those high temperatures and for most locations we have seen rainfall, some of it really heavy.

The Davis Vantage Pro at Northampton County recorded a rain rate of 110 mm per hour last week, so that’s roughly 4 1/2 inches per hour in old money and judging by the stuff I drove through on Thursday, that would be no means be the highest we would have seen recently. It will have played havoc with bunkers and I can imagine there is some pretty thrashed ones around the country this Monday morning. Bunkers are the bane of a greenkeepers life for sure. A highly respected golf course super remarked to me once when I asked him how the pro’s were liking his course during a tournament…”Well Mark, the greens must be ******* ace because they’re bitching about the bunkers”….. There’s going to be a lot of bunker surfaces that need reinstating this week so hopefully golfers will understand and hang fire on the bitching.

The humidity has been so high recently, I couldn’t stop sweating whilst out for a run (Ok I’m unfit) and pausing on a lovely walk yesterday I noted that with all that humidity, leaf surfaces aren’t drying out either…Took this picture of a lovely Clover ley whilst out for a yomp, you can see the beaded up dew on the leaf quite clearly and this was 1:30 p.m…..

When we set off the nearest rain was 60 miles away, an hour into the walk and it went dark and the heavens opened to deliver 17 mm with associated thunder and lightning.

I love walking (and fishing) in the rain, my other half though….now that’s a different matter !

There’s about 30 mins between the two pictures below ;

Needless to say the combination of temperature, rainfall, dew and humidity will have kicked just about every plant pathogen into “It’s Christmas” mode over the weekend….so let’s see what’s in store for us this week as we move into the 2nd half of August and autumn waits around the corner.

General Weather Situation

The GFS output above shows how the heat has retreated down into France and that will allow a more westerly airflow to dominate I think over the coming week as Atlantic low pressure systems will push in.

As I’ve always maintained summer rainfall is the hardest to forecast and this week will be no exception to that. Starting off on Monday we have heavy rain already working its way up across northern England as the low pressure that brought the weekends rain slowly revolves around on its anti-clockwise axis. There’s rain too across the east and south west of Ireland as that low pushes it in from The Irish Sea. Some rain is already popping up on the radar across the south coast and Wales as well. Through the morning expect to see more of the same as that low introduces more moist air into the equation across the southern half of the U.K and Ireland. That northerly rain will continue its progression into the southern half of Scotland as well. So a potentially wet day for Ireland, some parts of England and Wales with Scotland getting off lightly I’d say. Temperatures are still hovering around the late teens and low twenties though and that provides enough energy to trigger those showers. Winds will be light to moderate and variable according to your position respective to that low pressure system.

Tuesday sees that low pressure system still producing rain across Ireland and the north of Wales, north west of England. As we move through the morning we will again see showers bubble up pretty much everywhere but probably northern England / southern Scotland will pick up the majority….probably that is…As we move through the day it looks like Ireland will see some persistent showers across southern counties whereas the majority of the U.K rainfall will be more northerly biased. They’ll still be some showers further south mind, just not as many as on Monday. With less showers and cloud we should see more in the way of some sunny intervals and with the wind changing round to the south west, that’ll help on the drying front as well. Similar temperatures to Monday, late teens in the north and west, low twenties further south.

Mid-week beckons and the reason for the south westerly wind change becomes clear as a southerly-orientated, Atlantic low pressure system looks to push in during the day. (see above)

So Wednesday sees rain, some of it heavy push into the south west of England and south coast of Ireland during the morning rush to the beach. That band of rain will then move north east across the south west of England and southern half of Ireland through the morning. Some of that rain will be particularly heavy across The South West and South Wales (sorry Jim). Through the day that rain will push into The Midlands, central England and East Anglia last of all, reaching the north of England as darkness falls. So for the north of England and Scotland you have a much nicer day with sunshine and pleasant temperatures. Down south and across into Ireland, less so, with mid to late teens the order of the day. Accompanying this rain will be some freshening southerly winds tending towards the south east later in the day.

Thursday sees that rain pretty much across all of the U.K with Ireland looking to miss it initially anyway. During the morning that rain quickly clears the bulk of the U.K and now the boot is on the other foot as Ireland sees rain push in from the south west and quickly move up across country so by midday it’s pretty much countrywide. Moving into the afternoon we see that low pressure push showers into the westerly coastline of the U.K, some of these will move inland but it is looking a much drier picture away from the western coast. A windier day than we have had of late, especially for Ireland and the west of the U.K where that low pressure will rattle in those showers. That low pressure is butting up against a continental high and the isobars are packing in-between. So late teens for Ireland and Scotland, pushing up to the low twenties for England and Wales.

Closing out the week on Friday it finds us with that low pressure still sitting off the west coast of the U.K slap bang in the middle of The Irish Sea. That means a windy and unsettled picture for Ireland and the west side of the U.K with frequent showers from The South West to the west tip of Scotland. Through the morning  that low pressure system moves north up the coast of the U.K and this will sweep that rain across Ireland and inland across Wales, The North West and the west of Scotland. By Friday afternoon it is a clear /wet west – dry east’ split down the country with Ireland full of rain. As we approach Friday evening this rain clears to showers across Ireland and moves inland pushing rain into the north and east before fizzling out down south. Similar temperatures to the rest of the week, high teens where we have cloud and rain and low twenties in the sunshine.

It should be no surprise with low pressure dominating the weather picture as we come into the weekend that the outlook for this coming weekend is ‘unsettled’

Saturday looks to start off brighter and drier across the U.K initially away from the west coast where we will see showers from the off. Ireland looks to start wet and unsettled. As we move through Saturday morning those showers move inland across Scotland, Wales and England accompanied by a strong south westerly wind which will drop the temperatures into the mid to high teens. The east and south of England may stay pretty dry with sunshine hanging on there but it looks like a ‘hit and miss’ jobbie with the showers. As we approach late afternoon we see that rain over Ireland clear from the west and be replaced by sunny intervals. Sunday looks the better day of the weekend as the winds ease and so do the showers. We are still likely to see rain across the north west of Ireland and Scotland and this will push south and east into northern England but the bulk of the U.K and Ireland should be reasonably dry if a little on the cool and dull side…perfect for fly fishing 🙂

Weather Outlook

With the jet stream dipping this week to allow a more ‘Atlantic’ theme on the weather, how does next week look like shaping up ?

Next week looks at this stage like remaining unsettled with a new low pressure arriving into Ireland around midday on Monday and then sweeping wind and rain across the U.K & Ireland from Tuesday onwards. So potentially a quiet day on Monday before windy and unsettled sets the pattern for next week.  Tuesday and Wednesday look wet before high pressure looks to settle down the weather towards the end of next week. Tricky to say after that, there’s plenty of low pressure systems stacking up to push that high aside so we will see coming into September.

Agronomic Notes

The two graphs above illustrate nicely the change in environmental conditions over the last week or so. During the high temperatures we ran low humidities but as the temperature changed with the arrival of rainfall, the humidity shot up. Higher humidity means less E.T and so elevated periods of plant leaf wetness as shown in the bottom of the two graphs with high leaf wetness levels recorded on the 14th, 15th and 18th of August indicating rainfall but also dew formation. The more detailed graph below shows how the plant leaf wetness has built over the past week…

So it’s no surprise to see this lot popping up….

Anthracnose, Microdochium, Waitea Patch, Red Thread and Fairy Rings have all popped into the inbox recently due to the high humidity, high overnight temperatures and extended periods of plant leaf wetness.

The good news is that with the arrival of a south westerly airflow we will lose the humidity / stillness / lack of a drying wind and start ot push cooler air through the system. This will lower the disease pressure significantly. In addition the good growing conditions that will come with this change in weather will afford a swift recovery.

Would I reach for a fungicide with any of the above, well now there’s a question…

Anthracnose tends to respond better to cultural intervention rather than chemical once you have clear symptoms. Personally I would work the affected greens, overseed, topdress and make sure my fertility is spot on because it’s leaf tissue N and K levels that are key. The change in climatic conditions may just help the affected Poa plant develop new rooting from the damaged crown area and you may just be lucky in that respect. The image above shows just that process occurring so anything you can do to help mitigate this in terms of aeration, biostimulant usage, dropping your PGR out of the tankmix will all potentially contribute positively. That’s if you want to keep the Poa that is 🙂

Microdochium – Well most of this will grow out really quick in the next week or so but you may think about spraying if you have a high level of affected areas and particularly in Ireland and Scotland where August and September can represent some of the worst disease pressure from this pathogen. The problem is your choice of fungicide is limited, it won’t last for long and you haven’t many rotational partners to choose from currently. Personally I’d rather put a hardening spray down and grow it out.

Waitea Patch tends to come and go with the level of soil moisture and since we have a wet week on the cards potentially you are likely to see it prevail through this week though the cooler temperatures will discourage it a little. It does respond to Azoxystrobin in some cases but again you may just want to sit it out because it doesn’t tend to damage the surface unless we get a lot of heat / desiccation. The same can be said for Fairy Rings.

Red Thread will be showing a lot this week on outfield turf, tees, approaches, fairways and pitches. It isn’t just linked to fertility either like all the disease charts like to say, humidity and plant leaf wetness drives this pathogen and maybe the use of cultivars of Fescue and Ryegrass with poor susceptibility ?

That period of sustained high temperature and E.T has left its mark though on outfield areas and particularly those with high levels of surface organic matter. As we have discussed before and particularly during the dry summer of 2018, that organic matter effectively ‘cooks’ the grass plant in situ leaving behind burnt out areas of dead turf. There’s no other way to treat this than remove the fibre or punch holes through it into the soil below and drop some seed and dressing down. Costly and labour intensive it is I know.

Think about the grass plant…

I was thinking about this over the weekend.

That heat last week was sustained and really brutal. Maybe it’s my advancing years and declining memory but I can’t remember anything quite like that before ?

Looking at the Growth Potential stats for August above I can’t also remember seeing it drop to a theoretical 28 – 30% of optimum because of the heat ?

So think what the grass plant has been going through….It has been in sustained moisture conservancy mode for the last two weeks or so, stomatal pores closed with minimal growth potential over last week and then all of a sudden, the temperatures drop, we get rainfall and the Growth Potential increases from 30% of optimum to 94% of optimum over a 24-hour period.

So if you are looking at lots of clippings and slow greens with golfers employing their selective memory capacity, you have my sympathies. “The fairways are long, the greens are slow and the bunkers are washed out”….you’re going to hear it all this week and boy do you have my sympathies. ‘Tolerance’ is an oft-used word, difficult to practice sometimes in the face of a consistent barrage of ill thought out comments from an audience that doesn’t tend to subscribe to the ‘you have two ears and one mouth’ philosophy of life. It’ll pass, for sure it’ll pass.

Short and sweet blog this week…

All the best….

Mark Hunt