16th December

Hi All,

This picture tells a bit of a story, firstly that it’s pretty tricky walking on any footpaths at the moment hereabouts because lots of places are underwater so roads are the only option. Secondly, the field in the background would normally be home to a crop of Winter Wheat or Barley by now, but the wet autumn has meant many fields lay fallow after saturated ground conditions have made ploughing and / or drilling next to impossible on Leicestershire clay. This is already having a knock on effect for farmers with income down and yields likely to be much lower because lower-yielding spring crops will be the only option for many, if there’s enough seed to go round. It isn’t just our industry that’s feeling the weather pinch.

Lovely skies at this time of year though sometimes.

So last week I showed the first projection for Christmas Day and that was a high pressure system which kicked off alarm bells with the potential for disease development over the Christmas period ala 2018. Well that high pressure is still lurking but not for Christmas day (see below) so potentially we look cool, dry (ish) and dull for Christmas Day with some wintry showers up north possibly. Looking on the bright side there’s now an increased chance of some of my Paddy Power White Christmas bets coming off in the north of the U.K 🙂

OK, onto the general weather situation…

General Weather Situation

So Monday sees a low pressure system sitting off the north-west of Scotland and that will push some wintry showers and heavier spells of rain into the north west of Scotland and Ireland during Monday morning. Later these showers will more inland over Central Scotland and turn more wintry over higher ground particularly. Away from these rain fronts, the rest of the U.K and Ireland should stay reasonably dry except for some showers on western coasts. After dusk a front off the continent will move into southern England bringing rain to the south east and East Anglia overnight. Nothing to shout about temperature-wise with 6-8 C likely. A strong to moderate south-westerly wind will decrease through the afternoon and swing round to the south east later in the day.

(Sorry for the missing degree symbol but WordPress has revised itself over the weekend and I haven’t a clue where to find a symbol insert button….why oh why do people change things for the sake of it ???:)

Tuesday sees that rain over the south east of England slip away into The Channel soon after dawn leaving a pretty dry start over most of the U.K and Ireland. That south east / East Anglia rain front will lurk for pretty much all of Tuesday periodically pushing in to bring more rain to already saturated conditions. Elsewhere save for the odd shower over North Wales and the west coast of Ireland, Tuesday looks dry. Lighter winds for Tuesday with north westerly veering westerly likely and not much change from 6-8 C again temperature-wise.

Wednesday starts dry for everyone but we have another Atlantic low pressure system pushing into Ireland over the course of Wednesday morning with rain and strong southerly winds pushing into the west of the country and moving eastwards through the morning. Some of this rain will be particularly heavy on in the south of Munster with Cork likely to get a clattering I am afraid lads. This heavy rain and strong winds looks to stay centred over Ireland through most of Wednesday so that means dry conditions again for the U.K until Wednesday evening when that rain front will push into The South West, Wales and the west coast of England. Similar temperatures to Tuesday for the U.K, but Ireland will feel milder in that fresh southerly wind.

Thursday sees that rain front well and truly straddled across all of the U.K with a drier, colder start for Ireland. During the morning this band of rain will slowly edge eastwards across the U.K clearing the west and south as it goes leaving showers behind for it and the south of Ireland. Through the afternoon the rain pushes northwards into Central Scotland clearing the north and north west of England by dusk hopefully. Much windier through Thursday with strong to gale force southerly winds and much milder as well with temperatures lifting into double figures for the first time for awhile.

Closing out the week on Friday and we have low pressure sitting off the west coast of Ireland so that means a showery and unsettled theme for the end of the week with plenty of blustery showers pushing across all areas and some potentially heavier rain for The South East and Central Scotland. Ireland will have less of those showers strangely being closer to the low pressure. Through the afternoon, those showers will merge to longer spells of rain across the south of the U.K, Midlands, north of England and Scotland. Ireland should see the bulk of the showers confined to westerly coasts. A little cooler on Friday with temperatures around 7-9 C and still with a strong to moderate southerly wind though it will drop at dusk.

The outlook for the last Christmas Shopping weekend (hmmm must start soon) is unsettled with the U.K starting dry on Saturday. No chance of the same for Ireland though as another low pressure system pitches up and brings strong winds and heavy rain for Saturday morning. This rain will push over The Irish sea to give a soggy end to Saturday for the west of the U.K. Overnight this rain pushes across the U.K to leave a very unsettled picture for Sunday for both Ireland and the U.K. Showery across the south and west of Ireland and the south of England, Midlands with heavier rain for the north of England and Scotland. A moderate to strong westerly wind in situ for most of the weekend if anything strengthening on Sunday. Same old, same old temperature-wise for the weekend, 7-9 C with maybe southern areas pushing into double figures on Sunday.

Weather Outlook

At the beginning of this blog I mentioned that the high pressure projected for Christmas Day last week had slipped away. Well it hasn’t gone far. So next week looks like starting off pretty unsettled after Sunday’s high winds and rainfall. Monday looks to continue that unsettled theme with further showers and heavier spells of rain across the south and on western coasts. This will continue through Tuesday with a higher likelihood of showers on western and north western coasts and across Ireland. As we go into Christmas Day, the winds turn more northerly and this lowers the risk of showers further south but increases the chance of wintry showers across Scotland and the north of England. Overnight into the 26th December, a ridge of high pressure picks up and will maintain that northerly wind direction so cold, drier and potentially frosty for Boxing Day. At the end of next week we see a new low pressure push into Ireland, the north-west of England and Scotland accompanied by milder, south-westerly winds. Further south we hang onto that high pressure and that’s to me when we run a higher disease risk, later on in Christmas week across the south of England. By the end of Christmas week, that high pressure looks to get nerfed out of the way, allowing Atlantic low pressure systems to once again influence our weather, so that means a potentially wet start to 2020. Ho Hum.

Agronomic Notes

Above is the GFS output for the 27th of December and it is probably around the 27th, 28th December that we may see a heightened risk of Microdochium nivale, but mainly in the south of the U.K. As you can see high pressure is pulling up mild, south-westerly winds in a similar scenario to last year, but in Dec 2019 it is more likely to be south-orientated. For the west and north you can see it is cooler and windier and likely more unsettled. So we still have a risk of increased Microdochium nivale over the Christmas period I’m afraid with milder temperatures and heavier dews likely across the south of England from the 27th December onwards.

Spray Windows

The tricky bit is then finding a spray window and that isn’t easy because even with a window to spray in some areas during the first part of this week, ground conditions are saturated making getting a sprayer onto the greens looks decidedly tricky. With wet weather predicted for the latter part of next weekend, it doesn’t look like this situation is going to get any better any time soon I am afraid. Again we have a similar pattern to 2018 with unsettled weather leading up to Christmas and then high pressure coming through between Christmas and New Year. Not an easy situation to manage and you have my continuing sympathies for what has been a real pain in the butt period of weather over the last 3 months….

Fungicide Longevity – Earlier applications should be hanging in there…theoretically….

If we graph out the amount of growth defined by Growth Potential over November and December, we can see applications made in November should theoretically still be hanging in there with a total projected G.P of 8.2 for our location below since November 1st.

The problem is though that most of our current fungicides have lower levels of A.I and these A.I are less effective than their predecessors so as we are coming to the end of a fungicides longevity I think it is likely that they are less able to hold off an aggressive attack of Microdochium nivale. It is all theoretical of course and we must remember that most of the disease outbreaks we see from this stage of the year onwards are on existing disease scars rather than new infections. So if you are relatively clean now you have a lower risk of Microdochium over the Christmas period. A lower risk, yes, but not no risk as we saw over Christmas 2018.

Microdochium nivale disease pressure during wet and windy weather…

As some of you may know I’ve been doing a lot of work on leaf moisture and its role in the development of Microdochium nivale. In particular I’ve been looking at how spells of mild, wet and windy weather relate to leaf moisture levels.

Below are two graphs of leaf moisture taken over an unsettled period of weather in early December and using leaf moisture sensors located in different positions. One out in the open, one in a shaded and sheltered location. The difference is quite dramatic…

If you look at the period towards the end of the graphs, i.e the right hand side you can see we had some light rain and the sheltered location sensor stayed wet continuously whereas the open location sensor wetted up, but then dried down straight afterwards before repeating the pattern again.

So if we have a shaded green with poor air flow this is what we will see, extended periods of plant leaf wetness with a slow dry down, a higher propensity to dew and also frost and of course, Microdochium nivale.

Logical yes but when we have wet, mild and unsettled conditions and you are in an open location, you can see the plant leaf constantly ‘wets up’ and then dries down again which means it presents a much less favourable environment for continuous disease development.

A great argument to support increasing airflow and loosing a few trees maybe as going forward it’ll play a bigger and bigger role in an IPM program.

Ok that’s me for this week and nearly 2019 but I will probably try and slip in a mini blog either at the end of this week or early next week before I treat the PC to a well-earned break 🙂

All the best for the coming week…

Mark Hunt