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  • Writer's pictureMark Hunt

November 14th

Last week, I was on a bit of a educational conference tour on behalf of BIGGA. Starting off on Tuesday at Somerset County Cricket Ground, then onto Wentworth Golf Club on the Wednesday and I finished off on the Thursday at Aston Villa FC (pictured above).

Looking out of the window onto the pitch and already well into my second coffee of the day, It was a reminder to me that although the temperature was up in the mid-teens, the days are still short and light levels for Lolium perenne grown in a stadium environment are less than optimum.

I have one more talk to do this week on Thursday up at Elland Road and then I can relax a bit. For me, it's been a great experience. Great to bump into some of my old customers / friends and great to talk to and with my fellow speakers.

Let's face it when you are doing 3 hotels in 3 nights, it helps if you all get on :).

To listen to John Kemp from the R&A discuss Golf2030 and some of the themes we need to consider going forward as a game was thought-provoking. Marie Althorn from the RSPB did a talk highlighting how the RSPB now recognise golf courses as a brilliant habitat to conserve wildlife, be that birds, mammals and / or insects. We had Course Managers discussing their efforts on this front at their clubs and how the membership reacted. The feedback was largely positive.

We also had a thought-provoking talk from Michael Sawicki, Managing Secretary at Royal Birkdale. I knew Michael a long while ago when he was working over on the greenkeeping side of the fence. It was fascinating to hear about his progression to the heady heights of managing Royal Birkdale, how he dealt with Stakeholders and his course manager. He gave a really interesting and honest insight, thanks Michael.

I also tip my hat to BIGGA, to Tracey, Rob, Steve, Roger, Sammi and Jim for organising such an informative set of seminars (present company excepted of course).

Reproduced from the RSPB website, read about Starling conservation here

One theme that Marie from the RSPB talked about that really struck a chord with me is that it isn't just a one-way street in terms of nature benefitting from our efforts, we can benefit too.

A study done in Denmark showed that 45 broods of Starlings living on a golf course ate approximately 100kg of insects and these were mainly Leatherjacket grubs (and I think probably Bibionid larvae too because of their usual close proximity to the surface), so encouraging Starling populations on your golf course will introduce some predation pressure on your Leatherjackets. OK, it won't get rid of them, but it will reduce their numbers, without disruption, as Starlings have small beaks and tend to leave a Sarrell Roller type impression on the turf, unlike their larger Corvid cousins (Rooks, Crows, etc)

Food for thought maybe ?

Record breaking day and night time temperatures in November

Onto the weather and as we see stats coming in of the warmest November Day (21.2°C in Porthmadog, Gwynedd yesterday would you believe) recorded in the U.K, it does make you think our climate is changing and has changed already.

Ireland recorded their warmest November night ever last Thursday with temperatures at Shannon Airport not dropping below 15.5°C. Mullingar, Phoenix Park, Gurteen, Finner and Dublin Airport also recorded their mildest ever November night with temperatures some 10°C higher than 'normal', whatever that is ?

High continual disease pressure

The other week I did the Saltex exhibition with Prodata and I used some turf as a stand prop. I noticed disease in the turf whilst at the show and when I got back last week I had another look and it was mostly wiped out. This is Lolium perenne. Now where I had kept it was perfect for disease with no airflow and low light levels but it is indicative of the disease pressure we are facing currently, not just on fine turf.

General Weather Situation - w/c 14th November

So is the mild weather and disease pressure set to continue or are we still up against it ?

Well as you can see from the GIF above, that mild finger of warm air is now east of the U.K and is being shunted along by a very pronounced low pressure system. This signals that the Omega blocking pattern is on the move eastwards and we are set to pick up the other side of this blocking pattern and that is slow-moving, low pressure systems. Although the description of slow-moving doesn't immediately suggest high winds, it is actually indicative of this because the low pressure butts up against the high and isobars pack in behind it.

So after a quiet start to the week for some (east and central U.K) with light winds and fog, we are set for change. First up, note the appearance of blue on our weather chart, that means cool. Purple is cold.

That change is already occurring to the west of us as a wedge of rain is moving slowly over Wales, the north west of England and Western Scotland (where the wedge is widest and the rain consequently heaviest). So we will see rain and strong winds running to gale force push across Ireland in the early hours of tomorrow morning and this low will push eastwards across The Irish Sea to affect the U.K on Tuesday morning, clearing behind it from the west. Although the winds will be from a normally mild direction (south and then south west), it will feel noticeably cooler in those winds, with temperatures dropping to near normal for this time of year. The rain will be heaviest across central and northern parts of the U.K during Tuesday and Wednesday, with Ireland seeing a sunshine and blustery showers scenario. More rain and strong winds on Thursday as the centre of the low passes over Ireland and then the U.K, before a temporary lull on Friday with some sunshine, but feeling cooler with temperatures in the 8-10°C range. We won't be dry everywhere but they'll be less rain around, at a guess I'd say it will be confined to western and northern coasts.

For the weekend, we look to have a continuation of that unsettled picture with another low pressure pushing across Ireland on Saturday pm and then moving onto the U.K on Sunday morning. So more rain and strong winds for the second half of the weekend though with the high pressure pushed away to the east, these fronts will now move through more quickly, so we could well see sunshine and showers after they've moved through. So plenty of rain, strong winds and feeling cooler.

Weather Outlook - w/c 21st November

Well, it is an interesting look ahead because I think that the 2nd half of November will be cool, pretty wet, very windy at times and perhaps at the end of the month we will see some snowfall and frosts. It's the first time I have seen a purple-themed, low pressure system. Now it could change, but just a heads up, dig out your buffs and woolly hats maybe ?

So to put some detail on it, next week looks like starting off with low pressure in charge and potentially with a sneaky, southern England-based low pressure set to bring heavy rain to the south and south east of England on Monday. So a wet and windy start to the week, next week, with some heavy, localised rain followed by a potentially drier and brighter Tuesday.

Cooler than of later with 8-10°C the norm. From Wednesday onwards, we see another Atlantic low pressure system set to push in and so that means a very wet and very windy second half to next week, with heavy rain and some potentially very strong winds 26th, 27th of November. Thereafter we could be in for a drop of proper winter, especially up north but we will see, that's a long way away.

Agronomic Notes

Well one thing that is front and centre currently and that's disease activity, so I am going to take a detailed look at why the last week has presented such a challenge from a disease management perspective.

Using data from a Davis Vantage Pro weather station equipped with a leaf moisture sensor (shown above), we can measure dew formation (a key driver of most turfgrass pathogens) and specifically dew intensity.

So for Microdochium but also Dollar Spot, Leaf Spot and Red Thread, we need 4 key factors in place to favour fungal development ;

1. Mild overnight air temperature

Now this differs with each pathogen because they all have a 'sweet spot' which represents optimum growth. For instance, we know from research undertaken in the U.K, that Microdochium nivale will grow from 0°C and hits optimum growth at 15°C. Dollar Spot, Leaf Spot and Red Thread need higher air temperature to facilitate optimum growth.

2. High Relative Humidity

Now this is when it starts to get complicated because humidity is describing the moisture content of air, the higher humidity, the higher the amount of moisture it contains. It is also linked to air temperature as well because I read recently in New Scientist, that for every 1°C rise in air temperature, it can hold another 7% moisture. So the warmer the air, the higher the amount of moisture potentially present. This doesn't mean warm air is always humid. High humidity in the autumn tends to be associated with dew formation but there again this is dependent on a number of other factors.

3. Low E.T and wind strength

So, if we have a humid atmosphere with a high potential for dew development, it is likely to occur when we have light winds (so low potential for moisture to be evaporated from the leaf) and consequently low E.T. These conditions tend to be associated with high atmospheric pressure.

4. High leaf moisture levels - Dew development

A wet leaf surface is an ideal environment for fungal mycelium and spores to develop. Now this could be because of dew formation on the leaf surface when the air temperature drops to a point where water condenses out of the atmosphere. This is known as the dewpoint. It could also be when we have had a late afternoon shower of rain which leaves the plant leaf wet going into the hours of darkness.

Above we can see the air temperature last week tracked against the relative humidity. The red dotted line marks 10°C and really above that line Microdochium nivale as a fungal species gets motoring from a growth perspective. So we can see the air temperature hardly dipped below that line all week and was often well above it overnight. In other words, temperature and specifically overnight temperature was a key driver last week, over the weekend and into the start of this week.

Next up we have humidity and anything above the 85% dotted line is again perfect for fungal growth. Not only was it like air temperature and well above the threshold but it was close to 100% humidity over some nights, which means the atmosphere is nearly completely saturated with moisture.

The scale on the right axis denotes leaf moisture severity with 0 = a dry leaf and 15, a saturated leaf surface. We then have the number of minutes that the leaf is like this. So if you see a constant block of high leaf wetness intensity as we do on the 11th of November, we know that the plant leaf is saturated with dew. This continued from 18:00 on the 11th of November through to 08:00 on the 13th at this particular location.

That is 38 hours by my calculation when the leaf was wet. It also means if you were removing the dew by physical means, it would be reforming almost as fast as you removed it. So in this instance, a surfactant dew control is far more effective than removing the dew by a brush or Swish. Constant wet leaf = continual fungal development.

So there you have it, a perfect storm from a Microdochium perspective.

High overnight air temperature dove-tailed in with high humidity and plant leaf wetness. Now I only described one location and this was because the weather station there had a leaf moisture sensor fitted, so I could show you dew intensity and duration but I can assure you the above held for Ireland, Wales and Scotland as well as England.

With higher winds and cooler temperatures, it will mean disease pressure will lessen from tomorrow onwards looking on the bright side and finishing this blog on a happier note :)

OK, I have to skedaddle up to Nottingham City Hospital for a light bit of shoulder work, catch you on the flipside.

All the best.

Mark Hunt

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