4th March
Hi All,
A day late because I’m working up in Scotland at the moment and this afternoon I’m doing a talk at The Scottish BIGGA Conference so time is tight, my apologies. I happened to arrive in Scotland on a cracking early Spring day. The views across to the mountains of Arran and Ben Lomond, at the courses I visited were spectacular.
You’re probably wondering after last week’s rain: when we’re going to get a decent break in the weather, particularly for those guys down south?
Well, I am the bearer of potentially good news for some of you (particularly in the southern half of the U.K. and Ireland) because the answer is this week and at least some of next. Not only do we have some drier weather courtesy of that Atlantic high pressure I mentioned last week, but it’s also a warm high, which will funnel up warm winds from the south by the end of the week, it wouldn’t surprise me if we hit 15°C by the latter part of the weekend, so dig out the factor 30 and those shorts (leave your Desert Rat replicas in the cupboard Michael for the sake of office harmony :)). Now hopefully this change will really start to ramp up the E.T. rates and dry some surfaces out. (In the south)
General Weather Situation
Ok so where are we at present?
Going into Tuesday, that low pressure that gave us rain at the weekend will be moving away but still affecting the north of the U.K. and Ireland. We have some rain affecting the west coast of the UK and Donegal, falling as wintry showers over higher ground and this rain will move eastwards across Scotland during the day. Elsewhere we look to have a dry day on the whole: some scattered showers / lighter rain affecting the north-west coast of England, but dry and slighter warmer in the sun for Tuesday. Winds again will be westerly and light. Aside from Donegal, Ireland looks to have a drier day for Tuesday until the beginning of the afternoon when a rain front will push into Kerry and track north-east towards Leinster, fizzling out as it does so.
Wednesday looks dry again on the whole, with slightly stronger south-west winds (we need the wind to dry things out) and there’ll be some sun around, mainly over central areas of Ireland and the U.K. This must be one of the first days when I can’t see any rain around, except for the far north-west of Scotland, where there’ll be showers through the day.
Thursday starts off in a similar manner, but early doors a rain front pushes onto the west coast of Ireland and Scotland, potentially heavy in north-west Scotland. This slowly moves across Ireland during the day and pushes into the west coast of the U.K. by the morning rush hour, so a wet start here. Through the day, that rain intensifies over Ireland but, by and large stays isolated to the west coast. Elsewhere it’ll be dry with hazy sunshine and temperatures hitting double figures in a southerly breeze. A tad warmer at night as well.
Overnight into Friday, the rain front pushes southwards into The Midlands, north of England and eventually southern and central England, but as it does so it’ll fizzle out, so I don’t expect high rainfall amounts. It’ll still be sitting over the north-west coast of Scotland as well, failing as wintry showers here over higher ground. Temperatures will again be high single / low double figures, but they’ll be more cloud cover around due to that rain front. The rain should dissipate as we go into Friday night.
The outlook for the weekend looks pretty good for most areas of the U.K. and Ireland and, for a lot of you, you’ll really notice the temperatures rise on Sunday. I wouldn’t be surprised if we get to mid-teens by Sunday in the south of England for instance. Winds will be southerly and moderate. There’ll be a rain front pushing into the west coast of Ireland later on Saturday and overnight that’ll also affect western and central Scotland during Sunday, but east and south of this (That means east Leinster, Munster should stay dryish though it depends how far it pushes eastwards) it’ll be a nice with hazy sunshine, a southerly wind and if the sun breaks through those temperatures will really pick up.
Weather Outlook
Ok, so how are things shaping up next week? in a word, Mega!
Well ok, I have to be cautious here, we all know the weather can change, because seeing a high pressure establish for the first time since last November would be brilliant for us all, but as I look at Unisys projections, that’s how it looks. The high is set to build from the weekend, pull warm air up on southerly / south-easterly winds and that’ll mean warm temperatures, a dry weather window, with the low pressure systems pushed up over us. Now we all know this could change, but let’s see when we come up to Monday’s blog (I’ll be back to normal and home by then :))
Agronomic Notes
Downloadable GDD Spreadsheet
Firstly, some of you may have missed the downloadable Growth-Degree-Day spreadsheet, Paul put together a couple of weeks ago, so If you did, you can go to here to download it
Disease Activity
With the anticipated increase in temperatures from Sunday and next week, this may kick off some Fusarium activity, but I have a theory and you guys can help me if you wouldn’t mind by posting some feedback to the comments section on the blog. The main disease activity period last year was late summer, early autumn and for most, the onset of the cooler weather in November knocked it on the head. I’ve had very few reports of active disease aside from where Microdochium established during this period and then flared up around the edge of the patch in the milder temperatures of early January (see image right)
I’m interested to see what happens when the temperatures pick up, will we see new active Microdochium? If so, where will it occur across the greens surfaces you manage? My hunch is that any new Microdochium will occur on drier greens or on the drier part of greens (noses, mounds, tiers, etc.). If you don’t mind, drop me an email or post a comment on your experiences, it’s all grist to the mill and useful I can assure you.
GDD Data
Interesting one this, particularly this year when we’ve had such a mild winter, with very few frosts and very little likelihood of many more I guess? If you look at the GDD data for February from The Oxfordshire, we had 17 positive growth degree days out of a possible 28. Now of course early on in the month, day length and low light levels will have limited the potential of the plant to grow, but as we went through February and the days stretched out, the growth has definitely picked up, particularly on higher-height of cut areas like fairways, sports pitches, etc Comparing 2014 with previous years, January was on a par with 2011 and 2012 and February a little behind….
If you look at the cumulative figure for 2014 vs. previous years it gets even more interesting….
At the end of February 2014, we reached a total of 55.5 D °C (Cumulative degree days starting on January 1st =28.5 for Jan2014 + 27 for Feb2014), comparing that to 2013 and 2012, I can see the following ;
In the warm spring of 2012 (when we were under a warm peak in the jet stream) we reached the same cumulative GDD figure of the 23rd February, so we’re 1 week behind 2012 in terms of growth stage,
In contrast, during the very cold, prolonged spring of 2013 (when we were under a cold trough in the jet stream) we reached the 55.5 – Cumulative GDD figure on the 14th April, so currently we’re tracking 6 weeks ahead of 2013 using GDD data! Interesting is it not?
PGR Applications
All this gets me thinking about when and where we should start PGR applications and for me the default position is when your grass species are growing and you’ve achieved recovery from winter wear and tear. There’s absolutely no point in my mind in growth-regulating tees for example before you’ve achieved this recovery and have a good surface. In the U.S, they work on a different GDD model for applying Trinexapac-ethyl, using a base temperature of 0°C and a total GDD figure of 200, which roughly translates to 80 using my model. The 200 GDD figure concerns repeat applications i.e. you make a TE application and then when the plant has grown through 200 GDD using their calculations, you re-apply. It’s an interesting concept and there’s some good data around to back it up, see the link here You can also see that they saw no difference by doubling the labelled rate on TE in terms of growth suppression and longevity of effect, but you must treat this with caution because we’re dealing with primarily Poa (they’re working with Bentgrass) and their climate is much more stable than ours.
The question in my mind is when do you start though?
If we take the 80 GDD figure using my model and look at previous years data, that means you’d have started using a PGR (on higher height of cut turf) on the 5th March in 2012 and the 14th April in 2013. (using data from The Oxfordshire). That’s too early in my mind because looking at data from last year, good growth didn’t actually start until the 12th April, so that means the plant will have had 2 days to grow properly before you started regulating it. So 80GDD is too early, I think we’re going to be somewhere around 125GDD before starting TE applications on higher height of cut turf and maybe also on shaded turf areas like greens.
Shaded Surfaces
In this scenario you have a plant growing in low light conditions and it stretches up towards the light, elongating as it does. (Just like when you grow seedlings on your window sill, they go leggy after a while)
If you fertilise heavily, it only increases this effect and in addition uses up the plant’s carbohydrate reserves very quickly (which it will struggle to replace due to poor photosynthetic efficiency in low light). So if we regulate here, earlier, we may see some advantage in terms of sward vigour and density. Obviously that goes along with minimal organic matter removal (Why remove organic matter from a shaded green when the plant struggles to produce it in the first place?), minimal verticutting, scarification, instead concentrating on brushing, solid tining, topdressing and vertidraining at the appropriate times of year. I’d also be looking to raise the height of cut, maybe by 0.5mm on shaded greens.
All hopefully food for thought, ok it’s time for me to engage with the Scottish Conference, do my prep and cross everything 🙂
Have a good week and Happy Pancake Day, I’ve decided to give up Costa Coffee’s for Lent. What’s that? yep, a De-Caf – Flat White for me please luv… Ah well that didn’t last long 🙂
Mark Hunt
Stella Rixon
Hi Mark,
Great blog – excellent technical info, thanks.
I concur, have seen most Michrodochium on drier greens/ bits of greens….maybe it drowns in the wet!? Weirdly seen less worms in this very wet period too? Anyone else seen that?
mark.hunt
Hi Stella,
I’m doing a bit of work on this area at present, I’ll let you know when the research work is completed.
And yes you’re right, haven’t seen the worm activity I expected for a mild, wet winter, maybe saturated soils aren’t a great environment for them.
At least we’re drying out down your way (hopefully), though it’s a bit grey and drizzly today.
Mark
Gerry Bruen
Hi Mark
Attended the Scottish conference yesterday which I thought was excellent so well done to you and all the speakers.
Quick question I hope you don’t mind.
I like Greg have been using the GDD for my PGR applications for the last two seasons but I did stick with the figure 200.
I downloaded your GDD xl sheet and put data in for 2014 so far and will do so from now on.
So if you need reading from Glasgow let me know
When reading your last blog you say that using your model roughly 80 GDD would be the same as 200 just wondering how you got that figure, I am sure it will have something to do with the base temp 6deg .
I am not questioning it just wondering as I will use that for this season.
Many thanks
Gerry
mark.hunt
Hi Gerry,
Thanks for the feedback, that’s my fourth educational conference and for me it was great to be back in Scotland again.
I spent a lot of time in Perthshire as a lad and then on the Isle of Arran every Christmas, but haven’t been back for a good while.
You’re quite right, the 200GDD to 80GDD conversion concerns the base temperature used in each model.
The Primo Maxx one uses a base temp of 0C and I have settled on 6C, purely because I feel that’s when the plant starts to grow.
I did a rough calculation using the same temperature data for both models and it turns out there’s roughly a 0.4 times multiple from the 200GDD -0C model to my mine.
So in other words 200GDD on theirs equates to 80GDD on mine.
Hope that’s clear, thanks for making contact.
Mark
Stuart Green
Hi mark
Great to catch up again in Scotland today. Will see you soon!
mark.hunt
Hi Stuart,
Nice to catch up as well, always enjoy it.
Hopefully the feedback will be ok from our respective talks 🙂
All the best.
Mark
Greg Evans
Hi Mark
Another thought provoking blog!
Interesting on your microdochium paragraph. At Ealing we have been very clean all winter apart from one green, which from an agronomic view point is one of our better ones. Firm, full sunlight and minimal trees. Goes with what you say.
On the GDD and trinexapac bounce back trials, I read this a few years ago and trialled in at the 200 cut off. What I found on poa based greens is that this is too long a gap, as the poa is a more juicier plant than CB. I now set it at 150 and works much better. What it does mean is that during the season you are pretty much spraying every 7 to 10 days. Mind you the greens look so much better the shorter the interval:)
I’ve started to record the GDD’s that you spoke about at harrogate. Very interesting. In the whole of February we only had 3 non positive days. The two areas that I think it will help with are the potential for poa seedheads and disease outbreaks. If we start to know when they things might be happening we can put in place programmes to counter the affects.
Going back to trinexapac applications, there seems to be some research coming out of the states about applying it for 12months of the year. Especially well in to the autumn to make the plant healthier the following spring. It will be interesting to see how that runs over the next few years!
Keep it up!
Greg
mark.hunt
Hi Greg,
If it gets people thinking, then I’m happy 🙂
I read that the 200GDD was too long a gap for Poa greens and also in the U.S, they were banging on about the half-life of TE in warmer temperatures. Their suggestion was that tighter intervals in the summer months were more effective than increasing rate because the TE molecule itself breaks down quicker at higher temperatures. The tricky thing with U.S research is that their climate is so different, higher summer temperatures and for a lot of the U.S, dormant winters. Using TE to condition the plant before snow cover makes perfect sense, but over here as you know Poa can grow 12 months of the year and get Microdochium at any point in the winter. The thing for us is that light levels are a fixed PGR because whatever the weather we know we’ll get shorter days in the winter and that’ll restrict growth. I accept that it will affect Bentgrass more than it will Poa, but do we really see significant growth flushes from Poa over the winter months ?, not sure we do, but like you say it’s thought provoking, especially in shade environments. One last thought, I saw significant phytotoxicity last autumn / winter from fungicide + TE mixes, applied together, so that’s another thing to avoid in my books.
Thanks as always for the feedback.
Mark
Lee
hi mark, great read as usual
have a couple of spots of michrodochium on the 12th green, one of our driest greens
lee mkgc
mark.hunt
Hi Lee,
Hope you’re well, thanks for the feedback.
Next time I’m around, I’ll give you some background to my hunch 🙂
How’s the cycling going ?
I’m fat, at least 2kg over-weight and man do I feel it going up the hills, mind you I nearly cracked 40mph down them last week !
Mark