160418_gfs_pres_500p_loop_eur

Hi All,

????????????????????????????????????I spent the weekend back in my Motherland, Denmark and driving from Copenhagen I could see the woods filled with Wood Anemones which I think is late for them and there was plenty of lying water in the fields. Talking to my relatives beforetuborg multiple Tuborg Classics kicked in, they told me that the winter had been wet and mild for the 1st part with much less frost than they were used to. Now it seems that their spring is on hold, pretty much like ours and that’s the way it’s set to continue I’m afraid…..At least they didn’t have snow at the weekend like many of us did over here !

As we move through April and slightly milder weather beckons this week, I’d love to say that the heat building this week will be the nudge up we need to head us towards summer but it looks like it won’t be a permanent one. The trough pattern in the jet stream that has pretty much been in place now for two months looks set to return by the weekend and from then on it’ll dominate for at least another week..So let’s put some detail on the weather picture for this week and next..

General Weather Situation

Monday starts off dull and drizzly in a lot of places, but more so over Ireland, Scotland, The Borders and Northern England. They’ll also be a continuation of those weekend wintry showers over the Western Highlands of Scotland. As we move through the morning that drizzle and rain will sink south into Northern England and the east coast of Scotland will brighten up with some nice sunshine. This area of sunshine will extend down the east coast of England as we move through the afternoon, so Scotland looks to have a nice 2nd half of the day. Elsewhere for Ireland, Wales and England we see a continuation of that dull weather picture. Temperatures will be pegged back to low double figures under the cloud cover in light to moderate westerly winds.

Tuesday sees a similar start to the day as Monday finished, that means dull and cloudy for most places with any breaks in that cloud restricted to the north east coast of the U.K. It will be dry again though and at least that is a bonus isn’t it. As we go through the afternoon that cloud cover will begin to break and give longer spells of sunshine and under these temperatures will rise nicely into the low to mid-teens I think. That’s despite the wind direction shifting round to the north but the winds will be light so won’t influence temperatures unduly. Ireland and Wales will follow a similar pattern, plenty of cloud cover, but light winds and dry so not bad with any breaks in the cloud likely along the east coast of Leinster / Munster.

With clear skies overnight, Wednesday may start with a ground frost in some places but the flip-side is that it’ll soon be gone as temperatures rise quickly in the spring sunshine. At this stage it looks like this may be restricted to England, Wales and Ireland as Scotland picks up the cloud cover. Through the morning though cloud will build again but some areas may stay sunny all day. If you’re lucky enough to have this scenario you’ll enjoy warm sunshine and temperatures pushing up to 15-16°C, whereas under the cloud cover it’ll be more like 11-12°C. Remaining dry though and that’s a bonus.

Thursday sees a milder start to the day with that cloud cover preventing under temperature plunge and with some heat from the previous day it means it is likely to be the warmest day of the week if and only if you see the sun. If you don’t it’ll be similar to the rest of the week, i.e 11-12°C. I think the highest chance of seeing it will be over Scotland and if this is so expect 16-17°C. Winds will pick up from the east through the day and push cloud cover in from The North Sea and this heralds the beginning of the end for those temperatures I’m afraid. Later in the day there’s a risk of some rain pushing into the far south west of England and perhaps along the south coast as well.

Overnight into Friday and we really begin to feel the change in the weather (in the north first that is) especially along eastern coasts exposed to the moderate easterly wind. Here the ‘Haar’ will push in and peg temperatures back to high single / low double figures. That rain over the south west of England may continue through into Friday morning. During the late morning we will see some light rain and wintry showers kick in over Central Scotland and during the course of the morning these will move down into north east England. Ireland and Wales may have a better day with breaks in the cloud cover likely for the former area and since you’re furthest away from those winds it’ll feel a bit milder for you guys than the rest of us. So a dry end to the week for most of us except where those wintry showers are in situ over north eastern England.

Onto the all important weekend and what promises to be an absolute barnstormer of a Moto GP race from Jerez, Spain, miss it at your peril !! 🙂 Staying inside and watching it may be an attractive option looking at the forecast I’m afraid for the coming weekend 🙁

Through the course of Saturday we have two negative processes coming to play on the weather front. Firstly the winds will strengthen from the north introducing cold air and secondly a low pressure will snick down into the trough created in the jet stream and you know by now what that means don’t you 🙁

So Saturday sees the start of that process with a hard ground frost for Scotland (and other areas) in the early part of the night followed by wintry showers pushing in from the off on Saturday. A second front of showers over Northern England will also intensify and push down slowly through Saturday morning into the north Midlands. Ireland sees a similar picture with rain arriving overnight into Donegal and The North and this will track south into Leinster, Connacht and Munster for the start of the day I’m afraid. As this cold air pushes south it’ll feel significantly colder with high single figures the norm I’m afraid, quite a drop from the mid-teens of the preceding week. Some areas of the south of England may enjoy the milder air for longer on Saturday before it’s replaced by the cooler air stream. Sunday sees that cold, low pressure sitting in a trough slap bang over the U.K and Ireland and so that means cool and unsettled weather and a risk of a widepsread ground frost where skies cleared on Saturday night. Sunday sees strong to moderate northerly winds in place and a mixture of sunshine and showers, in the wind it’ll feel pretty parky I’m afraid. It should reasonably dry on Sunday and there will be some sunshine but there’s also a risk of wintry showers pushing down the east coast of England and Ireland for that matter.

Weather Outlook

As you might expect with the weekend forecast, the outlook for w/c 25th April isn’t exactly promising and believe me if I could type something more positive I would, that said these things can change so maybe the peak will win out and prevent the trough from doing its worst 🙂 At this stage though next week looks unsettled with frequent rain and wintry showers at elevation. With a strong northerly wind in place for the beginning of the week the outlook is cool with temperatures in the mid to high single figures I’m afraid. During Tuesday the wind will swing round to the west for central and southern regions but remain northerly for western areas and easterly over Scotland. It’ll be a windy first part of the week. It looks like we’ll see more rain for western areas through Tuesday and this will then swirl inland through the course of Tuesday and Wednesday. It won’t be a total right-off though as they’ll be some sunshine between the showers and that wind will be a drying one to boot. As we move towards the end of the week I expect things to calm down considerably with lighter winds, slightly milder temperatures and less in the way of those sharp showers around.

Agronomic Notes

Ok first off we’ll continue the theme running since the start of the year and get a GDD update..

Growth-Degree Day Update

GDDApril17201516

So looking at the top graph we’re touching 120 GDD y.t.d 2016 which is precisely the same GDD point as last year for this location however how we got there was quite different.

DailyGDD201516April17th

As you can see from the above we had a good growth period through the end of January till the middle part of February and then the wheels came off whereas in 2015 growth didn’t really commence until the end of February. March 2015 was a poor growth month but even so it was much better than March 2016. Our growth didn’t really start until the end of March and as you can see from the chart below it is still not getting to the point where we have good consistent growth, especially on fine turf. More to the point you can see that the cold nights and ground frost of the weekend put paid to any significant growth with a sharp drop in daily GDD.

DailyGDD2016April17th

Now I appreciate that in different locations we have different GDD totals, but essentially the pattern of GDD spread (i.e when it occurred) is I think similar.

Consequences of our GDD Pattern and potential plans for this week….

Poa annua seedheads….

I’ve been growing on some cores taken from a largely Perennial Poa-dominated sward and picked these 4 Poa plants from one of the pots this morning. It’s frustrating because I’m not kitted out to take good, close-up macro photographs but hopefully you get the gist from the image below….

From left to right you can see the stages of Poa seedhead formation ;

Far left, the Poa seedhead is just emerging from the leaf sheath, 2nd from the left, the seedhead begins to extend on the panicle, 3rd from the left, the seedhead is emerging from the leaf sheath and right, the seedhead becomes extended on its panicle above the grass plant.

Poaseedheadformation2

Now bear in mind these Poa plants have been grown on inside a house on a windowsill but because I’m a tight a**e with my heating I’d reckon the maximum temperature has only reached 16.5°C during the warmest part of the day 🙂

Further ahead than most of you guys though I know, but say down on the South Coast of England, your GDD is running 25% higher than The Oxfordshire shown above (so you’re probably at 150-160GDD y.t.d or thereabouts) and likely to be seeing more in the way of seedheads.

Poaseedhead1

In the real world (away from my windowsill that is…) I think you’re more likely to be at the stage shown above where the seedhead is developing down in the base of the plant and is slowly extended up from the crown. This is I think a bit ahead of where the U.S guys call “In the boot” but nevertheless it means seeding in Perennial Poa is imminent. (Remember I have talked about the difference in seeding between the annual Poa biotypes in previous blogs)

What is required is some warm days to initiate Poa growth and for some areas this week I think we’ll see that and hence a growing number of seedheads in the canopy. Now it won’t be a full-on seedhead flush because we are going cooler at the weekend, but I think from the end of this week you’ll start to see more and more in the way of seedheads across your managed turf areas. The time to act may be upon us pretty soon 🙂

Disease Activity

With the odd mild night / warm day last week accompanied by low cloud cover and drizzle, we saw an increase in relative humidity and this pushed on disease activity, particularly Microdochium nivale. It is perhaps somewhat inevitable now that this seems to mark the onset of warmer conditions in the spring but normally it also provides the opportunity to grow it out. The image below was taken in Germany where I think they’ve hit some warmer day time temperatures than we have had so far in April, but I’ve had lots of reports from the U.K of Microdochium activity. Over here it’s more the copper blotching across the sward and isn’t quite as aggressive as the image below, thankfully…

Mnivale0416

Nonetheless it may be something we have to think about this week because it offers us plenty of spraying and good uptake opportunities (as opposed to next week which doesn’t). Now I know a lot of you might not want to apply a fungicide, but a light rate foliar with iron may just hold everything in check this week from this disease perspective.

Selective Herbicide Applications

With some growth on outfields this past week we can see the first appearance of our spring broad-leaved weeds, particularly Daisies. Although it’s still a little early yet in my mind in some areas, some of the more advanced locations will have a good spray window this week for knocking back visible weeds whilst the opportunity presents itself.

Fertilisation

Although we are looking milder this week in some areas (till we slip back into our cold trough) we shouldn’t delude ourselves that both soil and air temperatures are lagging behind where they’d be in a normal spring. I say ‘normal spring’ but I don’t really know what that represents anymore 🙂

By this stage last year we’d had 10 days where the air temperature was at or above 17°C during April. This year we’ve had 1 in our Thame location.

For that reason it is important that we maintain a cold temperature-bias in our fertiliser usage currently with materials like ammonium sulphate, potassium nitrate, etc making up the majority of the nitrogen input, whether it be liquid or granular. During days when the air temperature rises to double figures you will also see a response from urea-based foliar applications however it will be short-lived if next weeks weather arrives and so a combination with our long-serving friend – iron, will be an advantage. (as this will give you colour even if the nitrogen does not)

Ok that’s it for this week, enjoy the warm sunshine if it makes an appearance with you and don’t put the Buff away just yet !

All the best…

Mark Hunt