As I type this email, I can hear my neighbours scraping some stubborn ice off their cars courtesy of only our second frost of the year and everything is white and crispy outside. That comes after a weekend when I could mountainbike in my shorts and a top on Saturday, as we touched 14.5°C and then we received 13mm of rain the next day and the temperature never topped 8°C, talk about topsy turvy weather !
My hedgepigs are still feeding every night, (costing me a fortune in Mealworms) but it’s during this week that they usually hibernate and around 100GDD after January the 1st, that they re-emerge ! (Oh yes they’re being monitored in a GDD model ! :))
I’ve had a lot of emails concerning the severe winter weather over in the U.S and the potential for it to come over here. In my humble view I think it’s very unlikely because before that cold winter airstream can arrive here it has to cross the Atlantic and the ocean is warmer than the American continental landmass, but just how warm is it I thought ?
So I went on the net to see if I could track down some info on Atantic sea temperatures and found this surf site with no end of stuff. Love the logo and strap line. My version would be “Sod the forecast, cast a line, ride a mountain bike, go for a run and try to forget about life for a couple of hours)
Anyway as you can see from the graphic above, the Atlantic is currently sitting between 10 – 12°C surface temperature, so any cold low pressure systems originating from the States have to cross this first and in doing so they’ll warm up, take more moisture on board and then dump it on us. The threat when it comes to cold and snow always comes from the north and east, it’s here we should be looking to for winter’s icy touch. So is mild, wet and windy how we are set to carry on ? more rain and lots of it ? well maybe not you’ll be glad to hear…
General Weather Situation
As intimated above, we have a bright, frosty start across the U.K and Ireland after a very wet Sunday, particularly for the east of the country, where I think Bury St Edmunds recorded 25mm of rain falling (we were half of that in The Midlands). And that’s the way we will stay for most of the day, save for Ireland where a weak rain front pushes into the west coast of Connacht / Munster this afternoon and pushes east and north. Later on this will reach north-west Scotland, but as it does so it dissipates. So for the bulk of the U.K, a nice, cold, dry day with light westerly winds and temperatures touching 10°C.
Moving into Tuesday we have a change in the wind, moving round to the east and so that may bring in some continental rainfronts into the south-west of England through the morning. Tricky to say as we know how fickle these things are but the odds are for rain to push into the south-west and South Wales through tomorrow morning, but maybe not reaching the latter until late in the evening. Elsewhere we have a vestige of Monday’s rain sitting over central Scotland, so a dull, wet day there, though amounts shouldn’t be high. Ireland looks dry and possibly even sunny 🙂 Temperatures will be similar to Monday and the wind, light and from the east. We may touch a ground frost again on Monday night by the way.
Come the middle of the week, we have more of a risk of continental rain pushing up from France into the south / south-west of England and Wales during Wednesday morning. At present this is orientated to move more along the west and east coasts, with lighter rain across central regions. Ireland should stay dry for most of the day with a risk of some rain later on in Donegal. The same goes for Scotland, but here that east coast rain may pop up at the end of the day to finish the evening in a soggy fashion. It’ll be a little cooler in a south-easterly wind and pretty dull with temperatures in the high single figures.
Thursday looks set to repeat this pattern with continental rain pushing in and moving up the west coast of the U.K, it may also push inland, but at present it looks like central and eastern U.K from the M4 up should be drier and we may even see the sun. Ireland and Scotland look to be mainly dry although there are some weak rain fronts kicking around that may affect south Munster later in the day. It’ll remain cool even though the wind will come from the west initially, swinging round to the east again through the course of the day. So temperatures again in the mid-high single figures, typical for late November actually.
Closing out the week, we have a dull, cool day for most of the U.K and Ireland, but again it’ll be largely dry and that’s what we need so don’t moan about the lack of sun 🙂 There may be some weak rain fronts pushing into Munster through Friday and later on some heavier bursts may just brush into Co. Mayo and Co. Sligo. For the U.K, another largely dry day, cool in a brisker, south east wind and in the south and Midlands you may see some sun as well. Further north it looks largely dry, but dull.
So how does the weekend look at this stage of the week ?
Well that deep northern low will kind of split the U.K in two, with the north affected by the low pressure system and that means, dull, windy with some rain, but nothing like what you were due to receive. Further south and I think for the majority of Ireland, we look dry, milder due to the wind direction, with some sunshine and a southerly / south-westerly wind, so that means not a bad weekend in my books. I’ll be heading up to Arran for my Christmas cheese run, first time on the island for years and I can’t wait to get ‘up top’ whatever the weather.
Now you may remember last week I said that the end of this week looked to be very wet as a new deep low pressure was set to swing in from The Atlantic, but that there was a chance a high pressure could deflect it ? well it has and that demonstrates two points ;
1. Long-term weather forecasting beyond 7 days is for la la land..
2. High pressure may just end up saving our backside in terms of deflecting some of that Atlantic rain.
So how are we looking for next week sitting here on a Monday morning with my Mystic Meg hat on and a second steaming mug of Kenco Costa Rican Instant on the desk ?
Well, we have a rare ceature making an appearance, an Atlantic high pressure system, that is set to push that low pressure off to the east. So that means unsettled for the north and north-east of the U.K for the start of next week as that low moves through, but further south and west, settled, cool, dry and possibly cold later on in the week, but the outlook is dry. By mid-week that low pressure is away and that means that the high begins to dominate, however it will produce a northerly airstream, so it will feel quite raw in the wind, crisp and sunny though, so don’t complain because we need to dry out and this should do just that for us.
One last point, it’s the first time that we have cold weather to the north and east of us going into December, so that’ll increase the chance of winter proper at some point in the future, but we will see.
I’m guessing that Saturday’s mild temperatures following on from a wet end to the week will have seen a resurgence in disease pressure for most ?, particularly on older scarred areas where the disease population is higher. Well looking at the weather that’s heading our way I think it’ll make disease management much easier because we’re losing temperature, maybe not totally because next weekend looks mild again, but for the majority of this week and after next weekend, I expect disease pressure to lessen significantly and that means life should be easier.
For the time-being if you’re going to apply a fungicide on active disease it has to be a contact because systemics will have very slow uptake at present. I’d always tankmix this with iron because we know from our own research work that there is a synergy between fungicide and iron in terms of maximising disease suppression. Are all iron sources the same though in this respect ?, no they’re not is the short answer and I’ll elaborate more on that in my short 30 minute BTME talk in January. For the time being I’d be looking to use an acidifying iron source with my fungicide application provided it is tankmix compatible of course.
1/2 Rate Systemic Fungicide Applications – When 1/2 + 1/2 doesn’t equal 1
I’ve had quite a few comments regarding fungicide rates of late and that age-old cheshnut concerning 1/2 rate systemic fungicide tankmixes and their efficacy. The simple answer here is that systemic fungicdes by their very nature are applied to give longevity of effect, whereas contact fungicides are as we know comparateively short-lived.
So if you half-rate a systemic fungicide, even if it’s mixed with another half-rated product, the result will be 1/2 the longevity of fungicidal effect vs. a full rate application. It’s common sense really, if you applied a fertiliser at half rate, you wouldn’t expect it to produce the same colour, growth and longevity vs. a full rate application would you ? Well systemic fungicide applications should be viewed in the same way.
Just as importantly we know that even with full rate applications sometimes it is very difficult to control disease outbreaks because the climatic conditions are driving the disease population growth faster than the fungicide can slow it down. If you subject the pathogen to half the concentration of active ingredient, then it follows that you’re only likely to make this situation worse, full stop.
True you save money in the short-term, but what price a scarred surface sitting staring you and your customers in the face all winter ? and of course if you have disease scars, the likelihood is that you’re going to have re-ocurring disease outbreaks during winters mild spells.
Lots of people commenting recently on worm activity and how bad it is this autumn. These comments are invariably followed by a suggestion that a recent Carbendazim application has been ineffective. When you look at the fact that we have had very wet and very mild weather this autumn to date, it is no surprise that worms have caused a lot of issues (and of course if you’ve made a Carbendazim application I think the volume of rainfall will have worked against its efficacy). Some people have applied sulphur with the carbendazim to try and acidify the soil surface and make the product more effective. This will work but to get the most from a sulphur application it must be made at least a month prior to the Carbendazim because in order to acidify the soil, the sulphur must be converted to sulphuric acid (and then to hydrogen ions) in the soil by microbial (Thiobacillus) activity. The equation goes something like this ;
So it’s not the sulphur that does the acidifying, but it’s subsequent conversion to sulphur acid and ultimately the production of hydrogen ions, this is what drops the pH (Remember from your school days that pH is the measurement of hydrogen ion concentration [H+], what do you mean you were staring out of the window at that point ? :))
So if you do try sulphur, apply it first, ideally when rain is due as you want it washed off the leaf and into the soil (else this may scorch depending on your rate) and then leave for a month before applying your Carbendazim. In a normal autumn this will mean applying sulphur in early October and then Carbendazim in November.
You can tell it’s been wet and mild of late and that we’re heading into winter because moss is now in the ascendency. I took this pic at the weekend of my shaded back lawn (Cue twitching neighbours curtains, “He’s at it again walking around staring at his grass” ). You can clearly see the new growth on the moss as the combination of low light and high soil moisture tip the balance away from grass and firmly towards moss. I believe that the period from mid-November to late-February is when moss out-competes grass on most playing surfaces (though it can also out-compete it during summer as well !).
So now is a good time to hit it with a high rate of iron, ideally combined with some nutrient because we’re trying to knock the moss back, reduce it’s photosynthetic ability, whilst encouraging grass growth to ‘out-tiller’ the moss and further reduce light availability.
Ok that’s all for this week, I hope you’re week is largely dry, that next week’s forecast stays on track and we all get a dry one 🙂
All the best.