May 20th

Hi All,

After rain and then some decent temperatures over the last couple of weeks, everything is growing at a rate of knots. The edges of fields that I walked through 2 weeks ago are now knee-high in grass with Cow Parsley (we call it Keck here), Pink,Red Campion, Vetch, Nettles and Cleavers shooting up from the verges.

May is definitely a growing month and I absolutely love the freshness of the countryside at this time of year. Some of you may already be looking ahead to the May Bank Holiday and wondering what that’ll bring weather-wise, well it is finely balanced, more on that later….

Image courtesy of https://johnmcphee.co.uk/photos/

Before I go onto my weather blog, big shout out to Scotland’s John McPhee for winning only his second Moto3 GP yesterday at Le Mans, cracking to watch…..well ridden John….

Tempus fugit this week so it’s onto the weather without further ado

General Weather Situation

Not a bad day to start the week with as Monday dawns with hazy sunshine and some cloud cover from the off after a mild (ish) night. Following a similar pattern to yesterday the morning looks dry but as we head to the afternoon, the combination of warm temperatures and humid air will kick off some sharp convection showers anywhere from the south east coast of England up through eastern counties and following a line along the M11  (not for the first time eh?). At the same time we will also see some more consolidated rain push into the south coast of England and the north-east of Ireland. Expect some showers as well across The Highlands of Scotland during the afternoon, some of these showers will be sharp. Ireland looks to have a dry day before some showers may bubble up across east Leinster later in the afternoon. Generally more cloud across Ireland so a little cooler. As we go through the evening those showers will rumble on and across Scotland those showers will form a more concentrated band of rain across The Highlands and north-east Scotland with some heavy rain to end the day here. A lovely day really for most with light to moderate north-westerly winds and temperatures between 15-18°C depending on cloud cover.

Tuesday sees that rain over the north-east of Scotland largely fizzled out but it won’t be going away entirely. Elsewhere another nice start to the day with hazy sunshine and light winds and climbing temperatures. That rain over north-east Scotland looks to drift south into central Scotland through the morning. Elsewhere dry with hazy sunshine and pleasant temperatures with perhaps more in the way of sunshine, especially for the west and no repeat of those sharp showers. A light to moderate north-westerly wind for the U.K (southerly for Ireland I think) and temperatures up in their high teens for everyone except Central Scotland.

Wednesday sees the U.K and Ireland under the influence of high pressure but sandwiched between two low pressure systems, one inbound from The Atlantic, one over the continent. It is this weather dynamic that is shaping the end of week / Bank Holiday weather and I think it will be very unpredictable to say the least. For the time being though Wednesday looks like serving out another largely dry day with plenty of sunshine and climbing temperatures, in the high teens for most and nudging 20°C across the south of England. Winds will be north-westerly / westerly and light to moderate.

Overnight into Thursday and we see a weather front from that Atlantic low push into the west of Ireland and move eastwards so by dawn it’ll be straddled across the country. Further east for the U.K we look to have another lovely start to the day with bright sunshine and warm temperatures. During the late morning cloud will build from the north and west and we will see the first rain across West Wales during the early afternoon. This will be joined by outbreaks of showers across the west / north-west coastline of the U.K. Ireland looks to stay unsettled and wet throughout the day. Quite a temperature contrast then with Ireland in the mid-teens and the U.K in the high teens / low twenties. The wind will swing westerly through the morning and begin to freshen through the afternoon.

Closing out the week on Friday and those showers over Ireland remain, maybe more westerly in orientation on Friday compared to Thursday. Those showers over the western coastline of the U.K have consolidated overnight into heavier spells of rainfall and these will move inland across Wales, North England, The Midlands and the south of England during the morning. Scotland and The Borders looks to have a lower risk of these showers and should have a pleasantly warm, if a little dull sort of day. By lunchtime the whole of the U.K looks pretty wet and for Ireland the rain will have cleared western coasts but not for long as another front is incoming. During the 2nd half of the day that rain spreads north into southern Scotland and consolidates. As we go through Friday evening that rain will move eastwards clearing Ireland from the west. Cooler on Friday with that thicker cloud cover and rain so down to the mid-teens I am afraid.

Now onto the Bank Holiday weekend and this one is a real tricky call because the outlook keeps changing from a GFS forecast point of view swinging wildly from washout to not so bad….

So my take looking at the current GFS output is this…..

Saturday will see probably the nicest day for everyone as high pressure pushes into the southern half of the U.K and Ireland, however the north / Scotland will be closest to the Atlantic low pressure system so as we go through the latter part of Saturday, a north-south divide will occur. Through the course of Saturday / Sunday the low pressure will re-establish its influence moving southwards and pushing the high out. This means that the north / Scotland will turn unsettled with cooler conditions and rain from Sunday and the south will hang onto better conditions through Sunday with that cooler, more unsettled weather arriving on Monday. Ireland being closer to the low will probably get the wrong end of the weather stick with wetter conditions expected in the west on Saturday and moving eastwards through the day to make Sunday and Monday pretty wet days as well. (but of course it is not your Bank Holiday thankfully)

Now this weather dynamic between the low and high pressure may well change as we go through the week but the above is my interpretation of 3 GFS outputs…..If they’re right, the beginning of next week will be cool, wet and unsettled and that may extend through next week.

Weather Outlook

As hinted above, next week’s weather is finely balanced between a Bay of Biscay high pressure obviously sitting south of the U.K and a northerly Atlantic low pressure system. Currently GFS output has the low dominating and keeping the high pressure to the south and that allows a strong westerly airflow with plenty of rain. Now that dynamic only has to tweak a little and that rain may push further northwards and not across the south of England.

My take is that the low pressure systems will win the day and I don’t seem to be the only one as I note the precipitation probabilities on Meteoblue are very high for a week out…

Not great amounts of rain shown yet but that will definitely change. So my take on next week is for a wet Monday, an unsettled but drier Tuesday before more heavier rain arrives on Wednesday. Thereafter unsettled with the threat of more rain arriving later in the week. Cool, mid-teens temperatures will prevail with reasonable night temperatures because of cloud cover so in other words good growing weather…

Agronomic Notes

Seedheads….

As predicted in a previous blog, the combination of rainfall and warmer weather has pushed Poa annua back into life but since it had already started its seedhead development, that’s what a lot of people have seen as consequence…seedheads.

I think the picture above was where Poa annua was sitting during that dry spell, i.e with seedhead formed but not visible and down ‘in the boot’ as they say. Once conditions changed the seedhead and panicle were quickly elevated above the canopy. This puts it out of sync a little with GDD because although GDD were advancing, the lack of rainfall had kept Poa from growing so realistically we can expect a few more weeks of seedhead flush before it begins to fade. The change from warmer weather to cooler conditions if it comes to pass will help in this process.

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Growth Outlook

As you can see from the Meteoturf above, the projected GDD total is 57 and 5.4 for total G.P, that means we are averaging 8GDD, 0.77 G.P per day, that’s 77% of optimal growth. So outfield areas provided you’ve managed to pick up some moisture lately will be getting a shift on and greens also will continue to display consistent growth. A couple of cooler nights at the beginning of this week will give way to more growth at that latter part of the week as cloud cover moves in. With light winds and dry weather this week on the whole and a potentially wet outlook for next week, we have a great opportunity to keep things under control from a PGR perspective.

Now some of you will be looking at areas that have been overseeded maybe last autumn, maybe dormant-seeded this spring and may well be wondering should I apply a PGR ?

The consensus seems to be that once you have a mature sward and good grass coverage (canopy closure) then you are fine to apply a PGR. On the contrary if your grass is still early in establishment then it is best to leave it, particularly if you are contemplating a high rate application of Trinexapac-ethyl (TE)   You may have a little more leeway with ryegrass because as a species it is least-affected by the application of TE.

So for me this week is about getting things under control, getting foliar applications out, PGR’s, selective herbicides, etc and this will be particularly important if we lose potential spray windows next week with the potential for unsettled conditions.

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Microdochium nivale

As you might expect with warmth and moisture there’s still disease pressure out there. As the above graphic taken from my Netatmo data shows we are running some pretty close air temperature / dewpoint data and that means high localised humidity on the plant leaf and a greater risk of Microdochium nivale. On the plus side with good GDD / G.P, we should be growing it out easily enough.

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Leatherjackets

I see there is lots of discussion on Twitter and feedback from the field on these fellers. Without a doubt population levels are high this spring and with no effective control in agriculture I guess the problem is likely to escalate. Now we were in a very fortunate position with a product like Chlorpyrifos, it was cheap and effective though if you remember once the larvae reach a certain size / instar growth stage, the chemical was much less effective (because the high fat content of the grub protected its central nervous system).

Last week saw the emergency approval of Acelepryn for 2019 with an expanded label. (https://www.greencast.co.uk/product/crop-protection/insecticide/acelepryn).

Last year I think it is fair to say that efficacy of this product on Leather jackets was mixed, some people saw less activity and consequently less damage by Badgers and Corvids, others did not experience good control.

Now we in an analogous situation to fungicides here, in that older versions were more effective and the newer registered products less so and therefore we have to approach the problem differently than in the past. It isn’t just a case of using Acelepryn like Chlorpyrifos, nor is it likely to be with a higher cost per hectare and usage restricted to one application.

Continuing that analogy, timing is everything and that’s probably a lesson we learnt last year. There’s some good advice on Greencast with reference to this but specifically when we talk about Leatherjackets, it is a complicated subject. As a fly fisherman I’ve noted adult Crane Fly on the wing for the last 10-14 days here in my location in The Midlands, it will be different in other areas of the U.K because of temperature anomalies and soil type. So it won’t be a one size fits all, we / you will need to understand life cycles much better and above all get the material into the ground prior to egg hatch so it has time to get into the soil as the grubs are emerging. In my mind that kind of rules out usage now because most of the grubs are at a later instar stage than the product will control and the main population – egg laying period will be in the late summer / early autumn as per usual. Remember if you apply now then that’s your one app per year gone.

Here’s some pertinent points on the Syngenta factsheet that you can access here

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Pest Tracker

To help build a countrywide database Syngenta are asking for your help in logging which species you have noted and where, simply by entering the species and your postcode in a PestTracker form. You can access it here

You can then see how the populations / reports are building for each species on a mapping tool accessible here

So hopefully with more data, better information, more site condition-specific recommendations will follow and these will increase the efficacy of the product.

Tempus does indeed fugit my friends as my 1 p.m. publishing deadline approaches so I must depart this blog 🙂

All the best for the coming week.

Mark Hunt

 

 

 

 

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