July 1st
Hi All,
Whoops – It’s July already! Really it is, how time flies! Firstly an apology, I like to think my forecasts are reasonably accurate, but last Friday’s was plain wrong… The rain moved in from the continent and extended further south, so pretty much everyone got a drop of rain, on the flip-side, the weekend was spot on lovely 🙂
Mock the jet stream at your peril – Reading last week’s New Scientist, I was amused to see it’s not just me that gets caught out by the weather, but at least I understand why :). Sarah Palin, prominent American politician, poured scorn on Global Warming recently when Alaska suffered a record cold snap, quipping “Global Warming, my gluteus maximus!”, which apparently means “my backside”. Shortly after, the jet stream duly threw up one of its peaks over Alaska and they recorded record high temperatures of 36°C! Read the article here and a separate meteorological report here.
Coming our way soon – our own mini summer jet stream peak ! – Some of you may have attended one of my recent talks, where I highlight the peak and trough nature of the jet stream, focusing on the trough events of winter 2010 and the summer of 2012. I also mention that we’ve yet to experience a summer peak i.e. where hot air is pushed up from the continent… Well I think there’s one on the way for next week, not sure how long it’s going to last for, but I expect it to be extremely hot while it’s here…
General Weather Situation
A cooler day than yesterday with more cloud, as a weak low pressure system pushes in from the west and brings rain to west Scotland during the morning, slipping south to affect the north of England and maybe the Midlands later in the afternoon in the form of showers. Temperatures will be high teens over the south of the U.K and winds breezy from the west. By Tuesday morning, a rain front is pushing into west Munster, Connacht and making its way eastwards, so a wet start for Ireland. That rain will reach western coasts of the U.K by mid-morning and mainly affect Scotland, Wales and the north of England during the afternoon, but later on there’s a chance of it pushing further south to affect more southern areas going into the evening.
Wednesday starts dull and still a little wet, with some light rain persisting over Ireland, Scotland and the north-west coast of the U.K. Further south it’ll be dull early doors, but the sun will push through to give hazy sunshine and temperatures will pick up a little, to high teens, on a north-west wind. Thursday is a carbon-copy of Tuesday, with another rain front pushing in to the west of Ireland early doors and moving eastwards through the morning to affect Scotland, the north of England and Wales. Further south, it should be mainly dry, with hazy sunshine and temperatures lifting into the low twenties as that peak slowly pushes up from the continent. By Friday, that rain is still lingering over north-west Scotland, but for Ireland and the U.K. it’ll be a warm day, with hazy sunshine and temperatures in their low twenties, so a really nice end to the week.
The forecast for the weekend looks very good, especially for Sunday when the first real heat from that peak is projected to reach us. You’ll notice because the wind will drop and that heralds the arrival of the warm weather. There’ll be a smidgen of rain affecting north-west Connacht, but everywhere else it’ll be dry.
Weather Outlook
As mentioned above, I expect next week to herald the arrival of a heatwave, courtesy of a summer peak in the jet stream. How long it will stay for is anyone’s guess? But certainly the early part of next week looks very warm, possibly cooling a little as we go through the week (but with temperatures still in the low twenties), before building again at the end of the week. Of course high temperatures can spark off thunderstorms, but we’re too far away to forecast these, so a dry outlook appears to be on the cards for most, with only Scotland / north-west Ireland possibly looking to receive some rain over this period.
Agronomic Notes
Disease Activity
It’s no surprise when you see a readout like this on the weather station, that disease has been very active over the last week. High temperatures, with rainfall and humidity are a breeding ground for fungal development with Fusarium, Red Thread and Superficial Fairy Rings being the most active of all the pathogens. It wouldn’t surprise me if there’s also some Waitea Patch doing the rounds as well, as it does like humidity and temperature.
Fairy Rings
Superficial Fairy Rings can occur in lots of shapes and sizes, from yellow vague rings (sometimes mis-diagnosed as Waitea I think) to the dark green sunken patches of Thatch Fungus. It’s worth noting that you can also see this disease where you don’t have a thatch issue per say, but usually it indicates excess fibre is present. It’s also worth noting where the disease is occurring on a green, because sometimes (not always) it can occur on an area where the pin in seldom placed (usually due to the design of the green), so foot traffic is less and fibre accumulation more. By the same mechanism, a tournament tee that receives little play builds fibre. This can then highlight the need for extra aeration on that particular area of the green, i.e double coring when the rest of the green gets one pass.
Treatment can be a little frustrating as we really only have the Strobilurins to work with (with Azoxystrobin seemingly the best of the bunch due to its mode of action) and in my experience, preventative applications are more effective than curatives. As mentioned on previous occasions, finding the depth of the fungal activity is key to treatment and to achieve this, I always suggest a droplet test, as the picture shows here to identify the depth of the rootzone where the fungal pathogen is active. Always tankmix with a surfactant (provided it’s compatible and approved of course :)) and if the fungal activity is deep in the rootzone, it may pay to solid tine to a depth just above this, prior to application. I’m going to post a fact sheet in pdf form later in the week to provide more detail.
Thatch fungus is a harder one to deal with because it tends to occur more intensively across a green and if fibre is present, the dishing effect can disrupt play significantly. Aerating can also be tricky because if it’s widespread, then the surface can be prone to heaving, so watch your tine sizing and spacing if you intend to do this. Again Strobilurins are the main port of call in terms of chemical treatment, but the real issue is organic matter and this can only be effectively addressed by aeration.
Button things down
If the heat does arrive as forecast, for however long, it’s good to be fore-armed and fore-warned in my humble opinion. That means using PGR’s to slow growth, where practically feasible (and therefore slow down the plant’s water requirement) practicing so called Pre-Stress Conditioning. Using low, balanced nitrogen inputs, continuing last weeks suggestion of mainly liquid / foliar fertilisation and ideally tank-mixing in a biostimulant, preferably containing seaweed and humic acid to maximise antioxidant production prior to the heat. Backing off on intensive aeration, especially lateral work like using the Graden or a deep verticut and instead just light grooming / brushing and if necessary, alternate cutting with rolling, if the heat looks like staying around for a while.
It goes without saying that irrigation and hand-watering (around golf!) is a given, but actually it doesn’t look like the wind will be that strong during this mini heatwave, so E.T levels should be bearable. Different from yesterday (Sunday) when we had very strong winds and temperatures up to 27°C in the south of England. I bet the E.T. was over 4.0mm (anyone care to post their weekends E.T. rates ?) and that means areas are currently drying out very quickly, even those receiving irrigation and last Friday’s rain. This weeks slightly cooler temperatures should peg things back a little and allow you to get moisture levels stabilised before the weekend.
That’s all for now, enjoy the summer..
Mark Hunt
Peter Todd
Thanks for the forecasting work Mark, much appreciated.
Our ET figures for last weekend were Sat 29th 3.35mm and Sun 30th 4.54mm.
Looking forward to that heatwave – Peter.
Greg Evans
Thanks Mark. Interesting comments as usual.
Regards
Greg
Mike butler
Thanks for a good forecast sexy knickers I am off barging all next week. We will be passing the foxton flight about mid week.
Hom
mark.hunt
If you want to meet up Barge boy, give me a bell and I’ll cycle down to Foxton Locks and shower you with squats and pinkies (maggots for the uninitiated 🙂
Mike Butler
How disgusting I shall tell the lock keeper to ban you from all local canals.
Hom
Greg Evans
Hi Mark
Just reading your excellent blog and indeed things are very dry here. Temps over the weekend was 22C sat and 26.3C sunday. Very nice:) ET for us was 4.1mm sat and 5.3mm sunday.
Just one comment on trinexapac-ethyl and seaweed. As you know trinexapac suppresses gibberellic acid but bio-simulants such as seaweed springs this in to life. What’s your thoughts on this? I haven’t applied seaweeds for about 5 years now as been an avid user of trinexapac and to me one counter acts the other.
Looking forward to the heatwave:)
Regards
Greg
mark.hunt
Hi Greg,
Good point and there is some anecdotal trial work (with a product called Astron) that high GA-containing products can reverse the effects of TE.
That said, there are many types of gibberellic acid involved in plant growth and GA1 (the one that TE inhibits production of) is only one of them, so in order to counter-act the effect of TE, the biostimulant would need to have a high content of GA1 specifically. I tested some seaweed products as potential raw materials a good while back and I could only find 1 lab that could do a total GA content, none of them could specifically isolate GA1 in terms of content AND tell me if that level was normal, low or high. There was wide fluctuation between different seaweed sources in terms of total GA content, but for me I don’t think you can / should judge seaweeds on content alone, as there are other substances they contain that are beneficial for plant growth and / or stimlulate other processes in the plant (like antioxidant production for example) aside from GA’s. An easy way of testing would be to apply TE with / without a number of biostimulants and measure clipping yield, but you’d have to have a universal stand of grass (as sward composition will affect the results) so this work should ultimately be done in a lab. (to be meaningful)
I work on the basis of allowing an interval between applications so that TE has time inside the plant to do its work before applying a biostimulant and of course (on a subject we markedly differ on), I don’t apply high rates of TE to greens turf.
regards
Mark