So we are now in the middle of July and we are in for some heat this week but before you start running for the factor 30, don’t get a large tube because it won’t last for long.
We are heading into another trough event by Wednesday / Thursday and that means cooler and wetter (sorry if you’re off on your hols) for all of us with the mid-week breakdown in the weather characterised by thunderstorms.
Out walking yesterday it was lovely to see so many Butterflies about in these days of doom and gloom when it comes to nature. I saw lots of Meadow Browns, Frittilaries, Red Admirals, Peacocks and Tortoiseshells but as yet haven’t seen the Hummingbird Hawk moth on any Buddleia.
That said, judging by the sightings reported on The Butterfly Conservation website though they are all around me here in Leicestershire…
You can see if they’re in your area by clicking on the interactive map here
By the way, don’t forget during these hot spells of weather to put some water out for your local wildlife, here I improvised with an old Nepalese Takeaway container (we are cultured round here you know) and this young female Blackbird has found it fits her perfectly 🙂
That rainfall of last Tuesday / Wednesday really came down in some areas with 38mm recorded in Surrey but just 7mm recorded here in Leicestershire (ho hum). Still it freshened things up and this week’s trough will likely do the same. So let’s put some detail on it…
Monday starts as a quiet day (or maybe it’s just me feeling that way :)) and looking at the Netweather radar we are dry everywhere with no rain to spoil the start of the week. That’s pretty much how it’ll stay today with the cloud clearing through the day across the U.K and Ireland to give long spells of uninterrupted sunshine. In that sunshine, temperatures will climb into the mid-twenties in the Costa Del Sol of England, with low twenties expected for Ireland and Scotland. Generally winds will be light and westerly but over Scotland they’ll be moderate to strong.
Quickly onto Tuesday and still we have high pressure sitting right over us so another very nice day for us all I think but not a totally dry picture this time. We are likely to see some light rain over South Munster during the morning and also across the south coast of England. At this stage it looks light in nature, but this band of light rain will push northwards into South Wales during the afternoon. Later on, a band of heavier rain will push into South Munster and move northwards reaching Leinster by the evening I think. This rain will become heavier overnight and also move into The South West of England and push up across Wales and into The Midlands during the early hours of Wednesday. Mid to high twenties today for the U.K and Ireland today buoyed by an easterly / south easterly wind.
Wednesday is the change day…
So for Wednesday we see some pretty heavy rain for Ireland particularly over the central Midlands at dawn. That rain over the U.K will be into the north of England but will fizzle out by the morning rush hour. At the same time that band of heavy rain over Ireland will push up country into Connacht, with lighter rain expected for Leinster. For the U.K we look to have a pretty dry start save for that light northern rain which will move into Central Scotland by the afternoon on Wednesday. Not a completely dry picture for England though as another band of rain is projected to push into the south east of England and then move northwards over Suffolk and Norfolk during the early afternoon. (What is it about Norfolk getting all the rain this year eh ?). By late afternoon we will see more rain over Central Ireland and this will push eastwards into Wales and then The Midlands later on Wednesday evening. Scotland will also see a day of thicker cloud and some rain through the afternoon with bands of rain moving into the north west of England and south west of Scotland through the night. Temperature-wise, high teens for Ireland and Scotland and again low to mid-twenties for England and Wales before the thunder and lightning arrives with a southerly wind now calling the shots.
Now when moist air meets stable hot air we know what the outcome is so for all of us expect to experience some thunder and lightning on Wednesday as that cooler moist front of air meets the stable hot air over the U.K and Ireland. Might be a muggy night.
Once again I mention the ATD Lightning Detector system that you can use to see where the storms are and where they are tracking…I use the portal hosted on the Netweather site here but there are plenty of other places to find it.
Onto Thursday and that northern low pressure that brought about the change in weather conditions is dropping south and exerting its influence. Initially this won’t mean rain but just thicker and more widespread cloud cover for all areas so a duller day on Thursday. That dry picture won’t last for long though as rain is projected to push into the west of Ireland and Scotland on Thursday morning and then track eastwards across the country during the morning / early afternoon. This rain is then projected to reach the west coast of Wales by the late afternoon but not make much more progress eastwards after that. During the evening that rainfall will have cleared Ireland but expect to see some showers across the north western coastline of the U.K overnight with showers returning to Scotland in the wee hours. A much fresher feel to the weather on Thursday with temperatures in the high teens for all of us.
Closing off the week on Friday we see more unsettled weather affecting the U.K and Ireland I am afraid beginning with a band of rain into the west of Ireland in the morning and this will then track eastwards the east coast of Ireland by the early afternoon. So most of the U.K starting dry on Friday except for some rain over eastern Scotland and East Anglia (again!). By late afternoon that band of rain will be into western Scotland and then Wales and the South West. Through Friday night the rain will push eastwards across all areas of the U.K setting the scene for an unsettled weekend.
So as hinted above, the weekend looks unsettled with a band of rain moving across England and Scotland during Saturday pushed along by a brisk south westerly wind. Ireland and Wales being west of this rain may be drier but everywhere will be pretty cloudy with temperatures in the mid to high teens at best on Saturday. The same applies to Sunday with the low pressure sitting off The Western Isles expect plenty of wind and rain up in Scotland. They’ll also be more rain for England but further west across Ireland and Wales you may see some sunshine and less chance of picking up a shower I think as the former begins to pick up the benefits of a warm Atlantic high pressure system. Temperature-wise I think we will be mid to high teens at best with a moderate to blustery south westerly / southerly wind in situ (depends where you are located vs. the low pressure system)
So next week begins with a battle between our resident low pressure system sititng over us and a warm, high pressure system trying to push in from The Atlantic. Now we know when we have two weather systems butted up against each other two things are likely. Firstly, the wind will be strong and secondly, likely from the north so I think we will start off cool next week and definitely unsettled. At present the projection is for the low pressure to stay in situ for most of the week so my prediction is unsettled with frequent fronts of rain pushing down into Scotland, Ireland, the north west of England and then across central and southern areas. So a late July dip in the weather looks on the cards. (good for fly fishing though so I’m not complaining :))
Well an interesting week last week with some heat and then rain, some of it torrential.
That combination of weather is behind the return of one of our still-to-be-sorted turf maladies, Etioated Growth or ETS – Etiolated Tiller Syndrome as it is known over the pond.
This is a really interesting but at the same time perplexing problem.
In the U.K and Ireland I tend to see the issue primarily affecting Poa annua but on that front I’d be interested to hear if any of you have seen any other grass species affected ?
I mention this because in the U.S, they see ETS primarily affecting Bentgrass. I have attached a pdf of some research work and if you download it here and read it, you’ll see they point the finger squarely at some specific bacterial species, Acidovorax avenae, Pseudomona ananatis and Xanthomonas translucens .
On examination of the affected plants (which incidentally look to display identical to our symptoms) they have found bacteria streaming from the plant under a microscope and what’s more they have isolated these bacteria, infected healthy plants and re-created the symptoms.
So an open and shut case then, ETS is caused by bacterial infection of the grass plant ?
Well not really because every time I have sent samples of ETS-affected plants away over here for microbial assessment, the lab have singularly failed to find any of the three afore-mentioned bacterial species in the affected plant. Strange eh but I’m not giving up on this one yet…
The research work then goes on to test if biostimulants and / or Trinexapac-ethyl exacerbate the symptoms of ETS ?
It should be pointed out on the latter that it doesn’t appear to be the direct effect of applying TE that causes the symptoms, rather that as the grass plant rebounds out of the regulatory effect of TE you see an enhancement of ETS.
We have talked about the rebound effect before but basically the theory is that TE is broken down by temperature, the higher the temperature, the faster the breakdown, the shorter the longevity. Applying their GDD analysis it translates to a predicted longevity of 12-14 days maximum from a TE application (to greens height turf this is) in the height of summer heat before the plant will then come out of the effects of TE and rebound. The rebound effect seems to mirror the regulatory effect, that is to say if you have 20% regulation by applying TE, you get 20% more growth when the grass plant rebounds.
Not sure if this extrapolates up rate-for-rate but one key point to make is that applying TE at a higher than the labelled rate (perish the thought) did not give more longevity.
So the take home is, it is frequency, not rate, that is important in keeping the grass plant regulated in the summer on greens. If you miss the boat and the plant rebounds and this coincides with hot humid weather followed by rainfall, you may see more etiolation than if you weren’t using TE. They also slightly point the finger at biostimulants that naturally contain gibberellic acid (GA) because GA (much easier for me to write and less chance of mis-spelling !) stimulates plant growth by enhancing cell elongation. It figures then that if the plant is elongating because of another as yet unidentified effect, application of a GA-containing biostimulant may exacerbate the effect. So let’s be clear, TE and biostimulants don’t appear to be causing ETS but they may effect its prominence / expression.
So last week I posted a picture of a Fairy Ring where the plant was clearly under stress and showing potential evidence of die-back.
When I did a droplet test on a core taken from the affected area it was clear to see that 45-50mm down the profile, the rootzone was hydrophobic and this was then causing issues with water and nutrient uptake, hence the discolouration. Below is a video you can download clearly showing water beading up at the bottom of the core but not at the surface.
So the grass plant displayed discolouration caused by hydrophobicity in the rootzone.
As a measure of contrast I also looked at some Fairy Rings last week that showed no hydrophobicity in the rootzone cores and the symptom expression was very different.
Here’s the two pictures side by side, the left showing plant discolouration due to hydrophobicity, the right no discolouration…
So one of the take homes of Fairy Ring management relates to irrigation and wetting agent strategy in the first place but also undoubtedly organic matter management.
For sure the symptom expression is also closely related to organic matter content in the surface of the green and I tend to see the worst symptoms on areas that have too much organic matter present. Typically these may be on areas of a golf green that don’t get regular pin positions and hence foot traffic and just like a back tee in a complex of tees, the lack of foot traffic enables more fibre to be created.
It isn’t always about excessive organic matter though because I remember regularly seeing Superficial Fairy Ring on newly-constructed USGA-spec greens in year one, long before even the highest N fertility program had produced surplus fibre. I always put this down to a lack of antagonistic bacteria and fungi in the rootzone because of the newness of the construction and typically they disappeared as the greens matured without need for any specific treatment.
Key to effective management is the droplet test to clearly ascertain where your problem lies from a depth perspective and then effective irrigation and organic matter management on these areas needs to follow.
The week ahead…
With high temperatures Monday to Wednesday this week followed by a forecast of cooler temperatures and rainfall, you don’t have to be a rocket scientist to figure out that we may well see a repeat in activity of the pathogens associated with this run of weather.
So unfortunately I’d expect more ETS, Fairy Rings, Waitea, Red Thread and probably more Microdochium which has been doing the rounds of late with a pronounced spike in activity last week on some sites. Sorry to be the harbinger of bad news but it’s to be expected when we run mid-twenties temperatures and then have rainfall. You can also probably expect a growth flush as some sites did last week when they got the heavy rain so my advice is keep the plant as healthy as possible and buttoned down with PGR during this period unless of course you want to grow out symptoms of foliar disease.
Speaking of foliar diseases (seemless link that…) It is possible that we will see increased activity from Dollar Spot on sites that are affected with this pathogen because of the anticipated periods of leaf wetness, a key driver to this disease. It tends to begin to show activity in the height of summer but then become much more aggressive in early autumn when we start to get the first heavy dew formation. Keep an eye out on any areas that have shown this pathogen in the past because it tends to start close to home in terms of past location and symptom expression.
Ok that’s it for this week and next week will probably only be a mini-blog as I have a family reunion in Denmark to attend. I’ll do my best though to keep you posted on what the weather has in store between a long awaited personal reunion with Tuborg Classic, Rundstykker and Spandauers 🙂
All the best.