April 15th – Updated 17th April

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Hi All, (Again)

I’m aware some of you didn’t receive my original blog published on Tuesday this week and so I’ve decided to re-publish it, but with an update pertaining to this weekend. As you’ll note I inferred below, there was a great deal of uncertainty conerning the weather over the Easter period and since putting together a forecast for this weekend, a scenario I thought might occur looks like it now will and this will affect the forecast for Sunday and possibly Monday in particular.

It now looks like a low pressure system will come in off the continent on Sunday morning and bring rain, pushing up on south-easterly winds, so it’ll affect the south-east first and then move diagonally up the country over the course of Sunday in a line from Kent up to The Humber and pushing up to south-west Scotland. So now Easter Sunday looks like being cool and potentially pretty wet for some. Thereafter we’re should be back on track, (but this cooler weather may extend into Monday) milder and unsettled for the week following Easter. At least you guys won’t be coming back to grass growing out of control and clippings round your ankles 🙂 and the courses on the east side of the country that need rain, should get it.

Ciao for now..

Mark

……………………………………….

Hi All,

A day late again, ho hum, but it’s that time of year I’m afraid, in reality it’s probably better as I’ll have more of a handle for the weather over the whole Easter period by doing the blog today.

That said, the current weather pattern is extremely unpredictable and therefore difficult to forecast. Anyone who follows it closely will have seen great variability in the next 5 days forecast, one minute it’s going cold with rain, the next it’s going to be dry. An indication of this variability will be the wind direction, which will change almost daily over the next 5 days. The reason for this (IMHO) is a split jet stream (see image below which shows 2 jet stream paths, one below and one above the U.K) which is usually a precursor for a change in the long-term weather pattern, again it’s happening in the middle of April, just like it did in 2012 and 2013.

jetstreamsplit

Image courtesy of Netweather Extra showing split Jet Stream

So how are we looking for the Easter period and beyond, taking on board that I type this with slight trepidation ?

General Weather Situation

You’ll no doubt have noticed quite a significant ground frost for places today and this will be a recurring theme for the next few days as clear nights, with little cloud cover see night temperatures tumble. Tuesday looks a bright, clear day for just about everyone, with just a little more cloud cover passing over Scotland during the day. Winds will be light and from the East / South-East and that’ll peg back temperatures to the low teens for most, maybe higher in Costa Del Southern England 🙂

Moving onto Wednesday, again we’re likely to see a ground frost to start the day, but this will quickly thaw as it’s set to be a warmer day despite a bit more in the way of cloud cover at the start of the day. A weak rain band is set to just tickle the north-west coast of Ireland during the afternoon, but it’s main effect will be over north-west Scotland where I think you’ll see significant rain from late afternoon and overnight into Thursday. For most of Ireland (save for north west Connacht and Donegal) and southern England, it’ll be a warmer day with temperatures in the mid-teens or higher, with gentle southerly winds, nice…..

That rain over Scotland is set to slowly sink south overnight into Thursday affecting the west coast, border counties and The Lakes during the morning. Elsewhere we should escape a frost with more in the way of cloud cover around, but temperatures should hold up well in their mid-teens, possibly higher in the east and south-east during sunnier spells. Winds will be westerly, but as we close out Thursday, they’ll start to swing round to the north and temperatures will drop sharply.

Good Friday should perhaps be more apatly named ‘Bloody Cold Friday’ as we see northerly winds take control. For some areas (East coast and Midlands) that may mean we’ll drag ‘Haar’ off The North Sea, so it’ll be dull and cold, high single figures under the cloud cover. Further north, south and west , it’ll be brighter so maybe just breaking into double figures here. It will be dry though for all of the U.K and Ireland.

Easter Saturday sees that wind swinging round to a more north-easterly aspect, keeping temperatures down in the wind, though again it looks to be dry. The colder wind means a more widespread frost, particularly for the north and west where they’ll be less cloud cover. Sunny with some cloud cover, but staying cool for the day unfortunately.Moving into Easter Sunday it may perk up a bit, particularly temperature-wise, pushing up into the mid-teens, so a better day on the cards, dry again with plenty of sunshine, but still with those north-westerly winds. There is some rain around on the continent and there’s just a chance it may swing up to affect the south-east of England / southern coast later on Sunday. Bank Holiday Monday looks very similar to Sunday, maybe more in the way of cloud cover about, but again staying dry and reasonably mild, if not particularly warm in those north-easterly / easterly winds.

Weather Outlook

So after a cool (ish) Easter, how does the 2nd, 4-day week on the trot look like in terms of getting everything back fine and dandy like ?

Well I expect next week to be unsettled, right from the off as the jet stream re-establishes itself and pushes a low pressure system in from The Atlantic. So from later on Tuesday, expect a milder airstream, (cool initially as the winds will start off in the north-west) from the west and rain pushing over, maybe not getting across to the U.K until Wednesday. It’ll be windier and those winds will swing round to the north-west / west during the week, so feeling cooler in the former. The unsettled theme looks like staying with us all week, so sunshine, mild, with frequent showers or heavier spells of rain looks the theme right into the weekend after this one.  Typical April weather you’d say…

Agronomic Notes

Growth comments

Well the feedback I’m getting is that greens growth is slow, but outfield growth took a real hike up early last week. Why ?, well because we had good GDD figures, had very mild night temperatures and rainfall, and that really kicked off outfield areas, particularly in the central, eastern and southern parts of the U.K, which had been dry (I know the west and north had not !) You can see this on the chart below ;

EarlyAprilGDD

Looking at the trendline for GDD you can see the up and down nature of growth, with frequent growth checks as we get cold nights dropping GDD right down. Today (Tuesday) is a good example with a frost to start the day and then we’ll be at low to mid-teens by 2p.m, but that means barely no GDD, so no growth. This up and down nature is set to continue over the next week or so, with some frosts and cool days, so do I expect a growth flush over The Bank Holiday weekend ?….No.

You will however see another outfield flush next week when we get a somewhat milder airflow and rain. Especially because the cloud cover and westerly winds will prevent the night temperature from dropping too far. (I expect it to be mid-single figures) and the days will be a little warmer. This will also push greens growth on a bit as well from it’s current low level.

 Current state of GDD

If I look at Sean’s data from The Oxfordshire, current up until today, we’re at 183.5 cumulative, y.t.d and what we’re seeing in terms of Poa seedheads is the annual Poa biotype is seeding profusely, but the perennial Poa biotype isn’t yet fully into its stride. It’s an accepted fact that outfield areas tend to contain more annual Poa biotypes and these tend to produce more seedheads than the perennials biotypes and start earlier. So I think the 150 GDD mark in terms of Poa seedheads for say The Oxfordshire is really applicable to annual Poa biotypes, rather than perennials.

As stated above, you tend to see more annual biotypes in outfield, higher height-of-cut turf and these pictures sent in from Adrian at York Race course (cheers) highlight that very well. The Poa below started seeding at 120-140 GDD

SAMSUNG DIGITAL CAMERA

On fine turf you’ll see more annual biotypes on greens that have been subject to thinning, be it from disease, wear & tear (clean up strip) or droughting out on noses, ridges. This is because the annual biotype is an A1 opportunist, always looking to seed into ‘voids’ in the turf. So you’ll tend to see greens with more annual biotypes seeding now and greens with the tighter perennial, just on the cusp. Looking at the fact that we’re going to have pretty low GDD’s for the next week, I don’t expect this to change much until next week when milder air AND rain will get the perennial moving. (By that stage it’ll be closer to 200 cumulative GDD

Disease activity

An interesting one this because we saw a lot of Microdochium activity last week even on areas of turf which had been clean all winter, despite the fact that the winter was mild and wet. So it looks like we have two seperate phases of disease development going on. If we get Microdochium establishing high populations in the autumn, then this has the potential to ‘flare up’ again repeatedly over the winter. If we don’t and we’re clean going into the spring, we tend to see that a new population of Microdochium needs high GDD and moisture to build up to a point that it becomes pathogenic, so what’s important here is not necessarily cumulative GDD, it’s the combination of high daily GDD and moisture.

If you look at the GDD graph above, most reports of Microdochium came in from the 6th April onwards, once we’d have some rainfall (and warm rainfall at that) and high night temperature pushing up GDD’s. So in future we can mark these combining factors as a warning for Microdochium outbreaks in the spring, regardless of what happened over the winter.

One of the notable problems though has been slow uptake of fungicides following application and that’s because of the frequent growth checks evident on the graph above. These will be further exacerbated if nutrition levels are low because systemic uptake by the plant will be sub-optimal.

Weed Growth

That growth flush in early April pushed everything into over-drive for a few days and driving along it’s notable how the verges have sprung into life. Not just the grass though because Dandelions and Daisy’s have also gone ballistic so suddenly you’ve got some big weeds visible. This week is a perfect spray week, but don’t expect weeds to keel over quickly because whilst spraying conditions are good, uptake conditions aren’t , particularly with the night frosts forecast. So I would spray but I don’t expect to see anything happen until next week when we have milder and wetter weather. Of course you’ll get much better uptake next week, but by then it’s likely to be windier and wetter, so your spraying conditions aren’t great. Isn’t that just typical 🙂

Nutrition

With the colder nights and days this week (at the end of the week), I expect greens turf in particular will start to look a bit peaky, particularly as some Poa will be ‘paling off’ as it diverts its energy from leaf and root production to seedheads. So greens may look a bit ‘peaky’, a bit purple blotchy like with the cold nights and warm days, (up to Friday) so for me I’d just give them a light foliar with iron and don’t expect to see a great deal until the low night temperatures desist at the beginning of next week. On outfield areas, it’s a good time to apply a granular fertiliser if you’re looking for a growth boost because of the rain forecast to appear next week.

Ok that’s it for now, it’ll probably be Tuesday next week as well for the next blog because of the Bank Holiday, so have a good Easter, keep the Poa seedhead feedback coming…If you’re off to The Azores to catch some southern sunshine, be aware that Lydia the Great White is in residence (lol :))

All the best.

Mark Hunt

 

 

 

4 thoughts on “April 15th – Updated 17th April

  1. Gerry Bruen

    Mark I hope you are well.
    Quick question hope you don’t mind.
    Whats your thoughts on recording your GDD figures and using that as a indicator of when all the greens grass species are actively growing.
    What I mean by this is using your data sheet I have added up to date since start of the year and on the 8th April I was 109.95 GDD.
    I feel the greens across the different species have now kicked in.
    The million dollar question is will this be proven to be a indicator every year around the same GDD figure that the greens have kicked in and if so is it a good indicator when to start the primo applications as you advised every 80 GDD.
    IF this was the case then I feel this would be a excellent way to communicate to the committee of where the greens are each spring in relation to growth.
    Or am I way of the mark LOL
    Many thanks Gerry

    Reply
    1. mark.hunt Post author

      Hi Gerry,

      Hmmm that’s a tricky one because I think of the variability within a grass sward even across 18 greens.
      For instance, over the winter I took some plugs from a green that looked visually identical when cut at 4mm, however when I grew them up in a pot of rootzone, the plants expressed themselves very differently, some were tight-bunch type Poa, some elongated, more annual biotype. predicting when all of these biotypes are growing is I’m afraid not just going to be down to GDD. For instance, tight perennial Poa biotypes are very sensitive to moisture levels, so we may have good GDD, but no rainfall and this biotype won’t be growing.

      It also depends very much on nutrition levels, again a low nutrition scenario will heavily influence growth regardless of GDD. This spring for example I’ve visited some greens which were aerated early and feed well, taking advantage of GDD windows, these are now presenting well (and have been for awhile), fully recovered from aeration and way ahead of greens that have had the same treatment, but the timing wasn’t optimal. The ‘hand brake’ that also seems to affect all grasses growing evenly is good night temperatures and we may not get these consistently till May some years. So in summary I don’t think there will be a cumulative GDD figure after which point all grass species are growing, more likely it’ll be a combination of cumulative GDD, moisture and high, consistent daily GDD.
      Hope that answers the question.

      Mark

      Reply
  2. Adam@tillersturf

    Great Blog as normal, quick question you mention ” image below which shows 2 jet stream paths, one below and one above the U.K) which is usually a precursor for a change in the long-term weather pattern, again it’s happening in the middle of April, just like it did in 2012 and 2013.”
    If you were a betting man….. which way do you think the summer may swing, hot dry summer or wet?

    Reply
    1. mark.hunt Post author

      Tut tut Adam,

      You should know better πŸ™‚

      Literally it’s too early to say and tricky with it because answering those kind of questions leaves me totally open to making a total t**t of myself.
      The way the jet stream is behaving leaves it hanging in the balance, literally it could go either way. I’d want a couple more weeks of weather pattern intepretation before I gave you a SWAG answer (copyright Dr James Beard) SWAG = Scientifically-Wild-Arsed-Guess πŸ™‚

      So I won’t be drawn just yet… πŸ™‚

      Mark

      Mark

      Reply

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