August 28th

Hi All,

Back from my trek to remote Alaska and a cracking time was had by all. 10 days with no phone network and no WiFi can only be described as bliss despite the fact that my ‘very wet and windy’ forecast for the first two days on camp turned out in reality to be a typhoon weather system that gave us 80mph winds, 3 1/2″ of rain in 18 hours and put 4ft on the river. Somewhere in the middle of it we also had a 4.2 earthquake thrown in to boot but nobody noticed much:) It’s quite an amazing landscape and ecosystem out there when you experience that kind of weather. We had a dry side channel right next to our camp suddenly become a running river and within 6 hours, Salmon were spawning in it and the Trout and Char (that follow them up for an eggs over easy meal) could be caught just behind the toilet block !

Plenty of wildlife including the ever-resident bears that were feeding up on Salmon before the winter in the same side channels I was fishing. It made life twitchy at times but the cracking Coho Salmon more than made up for it 🙂

Speaking to the native Yu’pik Eskimo’s in the village and local airport was also interesting and just like anywhere in the world, the subject of the weather is a great way of engaging in conversation 🙂 They confirmed that just like us, autumn and winter is their most-changed season with less snow, more milder and wet weather and importantly for them, less pack ice on which to hunt their winter food of Seals and Walrus. I had plenty of time to reflect on our extreme year to date with the cold winter, cold and wet spring and then one of our hottest and driest summers. I happened upon this article in New Scientist that suggests that research has linked a slow down in the Atlantic conveyor current with our rapidly changing climate (Not quite as drastic as a Day After Tomorrow scenario but the same rationale), you can read about it here.

As we amble out of August and a cool and sodden Bank Holiday over here that forced the cancellation of the British MotoGP (such a shame that 10.5mm of rain can halt an event like this), thoughts naturally turn towards the autumn and what the weather has in store for us.

We face a critical period over the next 2-3 months and without some of our more effective disease management products at our disposal. It’s going to be a steep learning curve and one that we will just have to get used to given our changing climate and current legislation.

General Weather Situation

So we start the week on Tuesday with low pressure sitting just to the west of Iceland (Crumbs isn’t that an expensive country, our stopover en route to Anchorage and definitely not the place to buy the 1st round of Tuborg in the airport bar !!!!) and high pressure trying to push in from the south. As you’d expect this gives us a north-south divide when it comes to the weather with dry and settled conditions for England, Wales, Ireland and Scotland for much of Tuesday. As expected with low pressure close by, it doesn’t last and by late afternoon we see a rain front push into the west of Ireland and north-west Scotland. This will slowly move south and east crossing Ireland through the night and pushing into south-west and central Scotland in the wee hours. Warm in the south of England compared to The Bank Holiday (The law of Sod) with temperatures in the low twenties compared to mid-high teens across Scotland and Ireland. Wales is somewhere in-between 🙂 The wind should be south-west but veering to north-west overnight.

Wednesday sees that front pushing further south with rain now across The Lakes, North and mid-Wales and a much cloudier start to the west of England to boot. We may also see some rain pushing up from the continent into the south coast of England through the early morning, tricky to say as always with this type of rainfall. Ireland has a much drier and clearer day with the chance of seeing the sun after the thick cloud and late rain of Tuesday. The same for Scotland as that rain front clears south. That rain will fizzle out as it sinks south leaving only a vestige of thick cloud through late morning / early afternoon. As we go through the afternoon, that cloud front clears from the west to give long spells of sunshine and a pleasant end to the day for many. Temperatures similar to Tuesday, maybe a degree or two down courtesy of a stronger north-westerly wind.

Thursday sees more of the same really with a settled day for all and a pretty dull one with the best chance of seeing the sunshine in the morning before thicker cloud moves in. Maybe just a chance of rain for the coast of Donegal during the morning, otherwise a dry picture presents itself. Lighter north-westerly winds on Thursday but with cloud cover, expect high teens and maybe just nudging into the twenties if you see the sunshine. Similar for Ireland, Wales and Scotland.

Friday sees the week close out with a very similar day to Thursday for the U.K with brighter periods across the west and east first thing before cloud cover moves in. That cloud cover is the result of a weak rain front that is set to push into the west of Ireland during the early hours of Friday morning and then move east across country giving Ireland a wet and dull Friday to finish off the week. By dusk that rain front has pushed thicker cloud and light rain into the west coastline of the U.K. With thick cloud cover for most on Friday we shouldn’t expect too much when it comes to temperature and so it will come to pass that we are all set for high teens to close out the week despite the wind swinging round to the south.

With Friday’s thick cloud base moving across the U.K, you can almost predict that Saturday will see wet weather across western coasts at the start of the day and this will move eastwards and fizzle out as it does so. So a cloudy and dull Saturday for the U.K and Ireland I think with it slowly brightening up from the west towards the end of the day. Sunday could turn out quite similar for some parts particularly Ireland, Scotland and Wales with a cloudy and dull day on the cards and some of that cloud will be thick enough to bring rain across Ireland and Scotland in particular. Now there’s a possibility that the 2nd half of Sunday could see that cloud cover start to break up and give some sunny spells but at this stage it’s tricky to forecast. Temperatures similar to the last 3-4 days, high to mid-teens depending on the thickness of cloud in your locality.

Weather Outlook

Now next week is an interesting one as we edge into September. Again it looks like a battle between low and high pressure with the latter winning the game at the beginning of the week with much warmer air pushing in and temperatures climbing into the low twenties I think for most areas. The complicating factor is a Bay of Biscay low pressure that could influence our weather from mid-week, next week bringing in some rain to the west and north initially and cooler temperatures as we close out the week. That said I think the south of England will hang onto the high pressure the longest so a dry and settled week could be on the cards for you. I say ‘could’ because whenever we have a Bay of Biscay low pressure it introduces the prospect of continental rainfall and this as we all know is unpredictable to the extreme. Time will tell but I sense the weather could tip either way as we get to the end of next week.

Agronomic Notes

With me being out of circulation for a couple of weeks I’m out of sync to a certain extent so expect this to be an abridged blog. I am aware though that we endured an extended spell of pretty humid weather with some mild overnight temperatures and that has kicked off a myriad of turfgrass diseases on outfield and fine turf alike. Dollar Spot, Leaf Spot, Red Thread, Rhizoctonia, Microdochium and Anthracnose have all appeared in my Inbox since I opened a jet lagged eye and tried to get my head back into all things turf. I looked at my own weather stations readout for the time I was away and the period between August 9th ad 14th in particular caught my eye….

Hopefully you can see that for that period we had 2 periods of high humidity (100%, you can’t get much higher!), one lasting 10 hours and the other 44 hours. The latter in particular would have meant a wet plant leaf for two consecutive days and nights and that’s enough for any disease to get cracking, particularly the ones that rely on growth of fungal mycelium across the grass leaf. During that same period at my location temperatures didn’t drop below 15°C and rose to over 20°C so in short it’s no surprise that we saw a sudden uplift in disease pressure.

Carrying over disease to the autumn….

One cause for concern to me bearing in mind the paragraph above is the potential to carry a high inoculation level of Microdochium (in particular) from August into September and more seriously, October. We had this a couple of years back and the consequences were quite severe in terms of disease activity and scarring. With the loss of Iprodione we no longer have the safety net of knocking back disease retrospectively and ‘cleaning up the sward’ prior to the main disease period of October and November (for England and Wales) and earlier for Ireland and Scotland. So what should be our approach ?

Well hopefully the weather conditions that we usually experience in September (warm days and cooler nights with low humidity) should work against the pathogen from a continued activity perspective but it will still be sitting there waiting to kick off with the arrival of the more usual, mild and muggy weather of October. This tends to point to starting your disease management program (in whatever shape or form it takes) earlier to put the pathogen on the back foot in the coming weeks before things tip more in its favour. Certainly this year is not a year to wait and see in my mind….

PGR usage on fine turf through into late autumn….

Last October was unusually mild, much milder than the previous year with 25-40% more Growth Potential across the month than 2017. Now we have had mild October’s before, 2015 springs to mind but back then we had more effective fungicides to control disease, now our choice is more limited and likely to become more so in the near future (although new products are arriving to market at the same time to maintain a degree of optimism).

Question – should we carry on our PGR usage through October and November with this in mind ?

Now I know some of you are probably reading this and saying, “yep I do already”…..Fine and dandy maybe but shouldn’t we consider the potential effect of PGR usage on fungicide efficacy ?

There are arguments for and against this approach, the obvious one being that if you regulate the amount of growth then you are potentially likely to extend the longevity of the fungicide because less is removed in the grass clippings. An argument to the contrary is the potentially negative effect on fungicide uptake of a PGR application. Along the lines of if you slow down the growth of the grass plant then you may potentially also slow down the uptake of a systemic fungicide.

It is an interesting debate and one which is accompanied by precious little recent research that I could find, particularly if we look at Poa / Bent turf and Microdochium nivale. I did find a paper (from 2008) which looked at the control of Dollar Spot on Creeping Bentgrass and the interaction between PGR’s and fungicide applications. The researchers found a potentially negative synergy between Trinexapac-ethyl and Propiconazole in some of their treatments suggesting that the PGR was interfering with the uptake of the fungicide. In the interests of a balanced debate, they also tested Chlorothalonil and found no negative synergy, presumably because it works as a protectant rather than a systemic and so isn’t taken into the plant. This might suggest potential PGR usage with a fungicide A.I like Fludioxonil maybe (Contact Protectant) which works on a similar basis ?

You can download the paper as a pdf here but I’d add the caveat that there may be more recent research available that provides a better insight into this question.

Ok that’s it for this week, next week will be the first week of September so anyone with GDD data, please send it in if you have the time and I will endeavour to do my usual monthly comparison 🙂

All the best.

Mark Hunt