In last week’s blog I mentioned that I could smell winter round the corner and last night we got our first proper frost of the year in The Midlands, so that makes me a smart chappy. (If only that were true :))
Nowadays October is almost seen as a weather extension of September with no real thoughts about cold weather commencing to November and winter proper saved for January and February in my books.
Now that the clocks have gone back, the nights are drawing in good and proper but it does give you the opportunity to have some lovely dusk walks, none more so than yesterday when I had a nice 8 mile jaunt across Leicestershire’s finest complete with the obligatory Latte and Flapjack stop
Apart from being a cracking walk, I chalked up a first in watching a pair of Short-Eared Owls hunting over some Fodder Beet fields at dusk. I’ve seen them before at known hotspots, but never out in the open countryside whilst walking. Absolutely lovely to see one of our diurnal Owl species.
I see that the tabloids are up to their usual tricks this year in forecasting a winter of snow storm hell and the like commencing in December.
Their weather contributors logic is that the jet stream is behaving erratically (no s**t Sherlock) and so is likely to plunge south and allow cold air to be drawn down from the North Pole.
Unlike a lot of their weatehr headlines, this time there may be some rationale in this because last week we were looking odds-on to pick up a cold snap this week from an easterly low pressure system that was doing just that. Fortunately it has moved eastwards into Russia so we are currently sitting under a peak rather than a trough. You can see this graphically portrayed on this Unisys GIF for todays weather with a mass of cold air stretching all the way down to Turkey.
So on balance I think it is more likely this winter than others that we will pick up some cooler weather but for now in The Midlands we could do with some rain with only 11mm for the month so far in October. Dry we are whilst other parts of the country are excessively wet like The South West, North West and Scotland, another consequence of the jet stream’s behaviour but I’ll talk about that next week when I summarise the month of October.
General Weather Situation
So we kick off on Monday with a pretty dry picture across all of the U.K and Ireland and where skies cleared overnight, a decent frost as well. So a cool day for us all with plenty of winter sunshine in the south and east of the U.K and across Ireland initially until some thicker cloud spills in from the west later this afternoon, eventually bringing rain to Donegal and north west Scotland later this evening. Temperatures may be just breaking double figures across the U.K in light northerly winds but milder across Ireland and the west as you pick up a westerly airstream.
Onto Tuesday and that overnight rain has moved south and east across Scotland and down into northern England. You’ll also see rain across Connacht through the morning as it moves north and west across the tip of Ireland into Scotland. A milder start compared to Monday across central and southern regions of the U.K and Wales due to a change in the wind direction from north to west but much less in the way of sunshine on Tuesday as thicker cloud pushes in from the west. For the 2nd part of the day we will still see rain across north west Ireland, Scotland and the north west of England as well. Temperature-wise, up into the mid-teens in that moderate to strong westerly air flow so a mild day to finish off October with.
Wednesday marks the first day of November and for Connacht and the west coast of Scotland, we will still see that persistent rain in place from the off and through much of the day I’m afraid, but it will tend to stay westerly coast-orientated. Towards dusk that rain and thicker cloud will push southwards across The Borders into northern England. Away from the north west of Ireland and the U.K, we should see another dry day with perhaps more in the way of sunshine and broken cloud through the day with thicker cloud pushing south and east across Ireland and the U.K later on in the day. Even without too much sun we will see another mild day with mid-teens likely across Ireland, Wales and England and a couple of degrees lower for Scotland and north west Ireland under that thicker cloud base and rain.
Thursday sees the last of that thicker cloud move off across Ireland and Scotland overnight to give a pleasant start to the day with varying amounts of sunshine. A cooler night though with temperatures down into the single digits and that’s because we are back in a northerly air flow. So a dry day for Thursday, but a cool one, with some winter sunshine probably more across the east and central regions of the U.K. Temperature-wise, just breaking double figures I’d say for Ireland, Scotland, Wales and England in light to moderate, northerly winds.
Closing out the week on Friday and we have an active low pressure weather system down in the Bay of Biscay and that is projected to push northwards into southern England during Friday to bring rain for the 1st part of the weekend. For Friday though we have another calm day and if I could summarise it, I’d say dull is the word for the end of the week with plenty of thick cloud across Ireland and just about the entirety of the U.K, with possibly the south coast seeing the only meaningful sun. Despite the fact that we pick up a westerly air flow, we will also be cool because of that thick cloud and lack of sun, so cool, dull and dry just about sums up the day. That said, that thick cloud may just be thick enough for some rain across the west coast of Ireland and Scotland, the latter more likely to get some meaningful rainfall.
So onto the weekend and as commented I expect that Bay of Biscay low pressure to make it a damp start to the weekend with rain pushing up across Ireland, Wales and England overnight on Saturday morning and lasting through much of the daylight hours, so if you have a bonfire made, it’ll be a damp one by dusk :(. Now because the low pressure is eminating up from the south it means that the north of England and Scotland should miss most of this rain with just pick up some thicker cloud and light showers through the day and these tending to be confined to the north west of Scotland again. A cool day under that thick cloud for England and Wales barely making it into double figures if indeed it does at all. Drier I think across the west of Ireland and really from Dublin north as that rain is south-focussed, just like in the U.K. Winds looks to be light and northerly on Saturday changing round to moderate westerlies for Sunday which promises to be the better day of the weekend, still cool though but with a much drier picture everywhere, with longer spells of sunshine, especially for the north of England and Scotland.
So this week we started off with a high pressure peak across the U.K and Ireland and next week it looks the same, but this one isn’t projected to last with a very deep low pressure set to influence our weather next week from the 2nd part of Monday. So I expect Monday to be calm, dry and cool but as we go through the day and from the north first, I expect the wind to get up pretty quickly pushing bands of rain down into Scotland and then the north of the country and Ireland, finally reaching the south of England later on Tuesday. Thereafter I expect it to be a sunshine and showers week as that low pressure pushes rain fronts across the U.K and Ireland on a strong westerly / north westerly wind. Perhaps more of the latter because it’ll remain cool with barely double figure temperatures, but that’s normal for November. Thereafter we have high pressure pushing in from The Atlantic so it’ll be interesting to see who wins that battle and what happens where the two meet.
Disease Pressure – What else ?
Without a doubt September and October, 2017 (to date) represent the most sustained period of high Microdochium nivale activity we have experienced in my time in this industry.
Usually September is a dry month dominated by high pressure, fine days, cool nights and relatively low humidity overnight. Not this year though, September 2017 followed the example of September 2016, in terms of high humidity and high night time temperatures making disease very aggressive. I’m not just talking about Microdochium nivale, but also Dollar Spot and late-season Take-all as well, which following the wet 2nd half of summer showed renewed activity on high bentgrass-content areas.
Next week I’ll present the full month’s data from different locations but for now I’ve picked a Central England location which will work for Ireland as well because the weather won’t be a million miles away from each other, though we do tend to run warmer, night time temperatures here.
So what I have graphed out is minimum air temperature on the bottom graph vs. maximum relative humidity above it. I have then shaded in individual days where the air temperature is > 10°C AND the maximum relative humidity is > 90%, as I feel this combination of climatic conditions leads to the most aggressive Microdochium nivale activity.
So if we look at the graph above, it covers a 59-day period starting from September 1st through to October 29th. In that 59-day period, we experienced 33 days when we had a combination of humidity and night temperature conducive to high Microdochium nivale activity.
That is just short of 56% of the period in question representing high disease pressure, with 3 distinct, 7-day periods. Tough going in anyone’s books.
Fungicide longevity vs. Growth – October 2017
I will look at all the stats at month’s end but I wouldn’t be at all surprised if October 2017 checks out as the warmest we have measured in terms of GDD / G.P, that alone has a number of implications.
Firstly, as I’ve already shown, the high temperatures, particularly at night, promote disease, and secondly and perhaps more importantly for our industry going forward, they also promote grass growth.
So if we are talking about the newer systemic fungicides with less active ingredient content (in systemic rather than protectant form because that’s what gives you longevity), how long do we think they are lasting ?
Well for the high A.I / more effective older chemistries like Tebuconazole / Prochloraz, I reckoned we normally got 24-28 days from an application in terms of outright longevity.
With the newer chemistries I have tried to map Growth Potential vs. Efficacy, starting in some disease trials last year. I’ll be presenting the data at BTME 2018, but for now I have looked at the growth patterns in October 2017 and plotted that against anticipated fungicide longevity.
I reckon we were looking at 14 days maximum longevity from a lower A.I, newer chemistry during October 2017 over in the warmer parts of the U.K, perhaps 5-7 days longer in Ireland and Scotland. That’s a sobering thought both in terms of efficacy and financially.
Even more so when you consider that by next autumn we won’t have a contact curative chemistry like Iprodione to fall back on when activity is at its worst.
Looking at the Meteoturf projections for the coming week across the four nations and you can see the pronounced drop off in temperature and hence growth / disease activity afetr we clear Wednesday. From a night time temperature vs. humidity perspective and the combination that we know promotes disease activity, I think only Ireland will have high disease pressure for the start of this week (because of the milder, westerly air flow) before that too drops off from mid-week onwards.
So the fact that we are picking up a northerly airstream and lower air temperatures both during the day and night will mean that disease pressure will drop off for now and in addition, any applied systemic fungicide applied recently, will last longer, which is good news. The continued spell of drier weather across the south of the U.K will also mean lower humidity levels until we get rain at the weekend.
Compare the above charts for the end of October / start of November with these below, which were from about a month ago. You can see the growth rate now is roughly 30 – 50% of what is was a month ago. That’s good news to me in terms of disease activity and control.
From a nutrition perspective I’d be suggesting just keeping the grass plant ticking over through the coming period because if you have some scarring from September / October, you’ll be wanting to get some re-growth. whenever conditions allow this to occur. Combining iron with that nutrition is a given and making the switch from warmer-temperature nutrient forms, like urea, to more cool temperature nutrient forms, like ammonium sulphate and potassium nitrate, would be prudent in light of the forecast.
Ok that’s it for this week, I’m off to prep for Saltex at The NEC and I hope to see some of you there if you’re intending to pay it a visit.
All the best.