Back from my travels for the time-being and what an interesting jaunt it was covering Germany, some of the U.K and Switzerland last week. Saw a lot of disease on my travels, particularly Dollar Spot, so I know a little bit more about this disease based on my findings… (more of this later).
You know I meet some odd people and come across some strange local traditions on my travels. None more so than an indigeneous population of rodents to the Frankfurt area called “Field Hamsters” or “Feldhamster” as they are known in Germany. Seemingly there are only 2 places in Germany where these wild Hamsters still survive. Now I thought all Hamsters came from Asia, but no I was assured by a course manager, who shall remain nameless (Chris Knowles – G.C.Hanau) that they are indeed wild and in fact living in a field close to his house !
I was extremely sceptical so agreed to go with Chris and his young Son, Olly, to see these mystery rodents. So we set off down the road to see the field where they lived….Imagine my scepticism when it turns out the field had been ploughed that very morning, how convenient…Fear not because apparently they burrow down 2m to escape the plough !
A day later I was enjoying a pint (or a litre) in my IBIS Budget hotel in Winterthur, Switzerland and couldn’t help laughing at the name of the drink “FeldSchlosschen”, which means Field Castle, presumably it’s where Feldhamsters live ???
So onto the weather and what a change we had at the weekend, well that’s what happens when we move from a peak (20-22°C) to a trough (10°C) overnight…..
General Weather Situation
So starting today, we have a vertical band of heavy rain moving across the U.K from west to east. If you’re dry now in the east, that might not be the case for long. Under the rain, it’s cool and well, miserable, 9-10°C, with a strong, blustery south-west wind. Still it’s marginally better than the frost we had on Sunday because we do need the rain. Further west that rain has cleared Ireland, though the western counties will remain showery. By 5 p.m, the west of the U.K is dry and bright with that rain band situated over the east of the country.
This intense weather system isn’t done yet and overnight into Tuesday it swings round to push into north-east Scotland, so a very wet start to the day on the cards there (and for much of the day really). Further south, a new rain band pushes into south-east Munster and edges up the coast into Leinster during the morning. This same rain band pushes into south-west England and Wales and tracks along the south coast, so again the south-eastern corner will get some much-needed rain. Again temperatures are disappointing. This rain pushes north slowly, but lightens in intensity as it does, so by rush hour it’ll be into the Midlands.
Overnight into Wednesday, that rain is still in situ over Scotland and the east coast of Ireland, so a mixed picture. If skies clear, temperatures will drop to low single figures, but maybe just high enough to avoid a ground frost, what a difference a week makes ! There’s more rain on the cards for Wednesday as that low pressure system swirls around again and as predicted last week, when a low sits in a trough, it doesn’t move anywhere fast. So another mixed day of showers, heavier spells of rain, pushed along by cool, south-westerly winds. It looks like the western coastline of the U.K (and Ireland) is in for most of this rain, though you may just miss it in Connacht as it passes south of you 🙂
For Thursday, that rain is still lingering, but by mid-morning it moves off from most of the U.K to be replaced with brighter, warmer weather, with temperatures pushing up into the mid-teens, hurrah ! They’ll still be some rain around though for Ireland, projected at present to affect south-east Munster and north-west Connacht. It will remain windy though, from the south-west, so a blustery day on the cards.
Closing out the week, we have some rain for the north-west / east of the U.K in the morning, but elsewhere it looks like remaining dry, bright and we’ll be keeping those temperatures, so nice compared to the beginning of the week. Those winds will drop back as well, so that’ll help.
So how is the weekend looking ?
Well not bad, but a little cooler (low teens) as the wind swings round to the north-west signalling that the low is moving away to pastures new. There’s a chance that rain may push off the continent on Saturday morning into the south-east of England, but we all know how unreliable this type of rainfall is, so your best bet is to keep an eye on the forecast as we near the end of the week. Dry on the whole though, but with the risk of showers over western coasts of Ireland and the U.K and some of these may move inland on Saturday.
Since we are in a trough, it’s only a matter of time before the next low comes in, but it looks like there will be a gap between them. So for the start of next week things looked similar to the weekend, a little cool because of the north-west winds, though these will be light in nature. The lighter winds and lack of cloud cover will push night temperatures down to a chilly 4-5°C in rural parts. for the early part of the week. From Wednesday we have a new low pressure arriving, another intense one as well, which is set to bring driving rain and strong winds into Ireland for Tuesday night / Wednesday. This low will track across the U.K on Wednesday / Thursday, but should move off by the end of the week. It all depends on its orientation, currently it looks like affecting more northerly and western climes.
I thought I’d start the blog this week by looking back at September because personally I found it a really tricky month from a turfgrass maintenance perspective.
The first area that I think was difficult to manage was soil moisture content and for sure a lot of greens dried out too much during the month and that compounded issues in terms of plant stress and associated diseases, like Anthracnose Foliar Blight. As you’ll see from the graphic below, although September 2014 was a dry month, in fact one of the driest on record (full stop), it wasn’t a particularly high E.T month. What I mean by this is that the loss of moisture from the rootzone rarely exceeded 3mm per day, whereas in the summer, we could easily hit 5mm plus on a hot, windy day, Therein lies the key because September was by and large, a light wind month and this is the driver of high E.T days, high temperature and strong winds.
A consequence of this low rainfall / low E.T combination is that the plant didn’t show drought stress as we’d normally see it in the summer, because it seldom reached wilt point and so areas of turf were under stress, but not showing it visually. This made it very difficult to intepret and act accordingly and for sure where a moisture meter would come in handy. Although even then with a moisture meter, because it’s reading at 60mm or 75mm (depending on the probe length / model) it doesn’t always pick up when the top 20mm is going dry.
Variable Growth Characteristics
I’ve charted out 3 sets of weather stats from The Mere in Cheshire, The Oxfordshire and Long Ashton, near Bristol. If you look at the green lines showing growth potential (G.P using 18°C as an optimum temperature), you can see just how variable a growth month it was. You can also see how different the shape of that line is between different sites.
For example, The Oxfordshire being a very open site and located in what is traditionally one of the coldest areas of areas of the U.K and Ireland, you can see how cold the nights got during September. This pushed the G.P down particularly during the 2nd week and last week of the month, so growth characteristics were very variable to say the least.
Disease Activity during September 2014
Anthracnose Foliar Blight
Looking at the stats above, you can see why Anthracnose Foliar Blight (in particular) was such an issue. It doesn’t matter whether it’s the north, middle or south of the country, we had no rain for the first 18 days, so areas were dry, under stress and ideal for development of this disease. During the middle part of the month we had a peak in E.T, hot days and mild nights and therefore heavy dews and this really motored Anthracnose Foliar Blight on, particularly on golf courses which had already shown the disease developing during August.
The image below taken on the 18th August shows mature Acervuli on the leaf and stem tissues of a Poa annua plant. Acervuli are the spore-producing structures and so here we have a disease that’s already in reproduction mode, ready to push it’s spores out and infect other plants. These spores are moved by water, traffic, machinery, golfers feet, anything really and so were nicely distributed across the green during late August, ready to infect new plants come a stressy September.
Thatch fungus really raised it’s head this year and particularly in early September when we had some very warm days after heavy rainfall at the end of August. So in other words excellent conditions for the development of Basidiomycete fungi, so the key driver was the weather, but also the presence of organic matter. As I commented earlier this month, Fairy Rings and Thatch Fungi aren’t the worst of our diseases, if and it’s a big ‘IF’ you have your organic matter under control. If the areas dishes significantly, then I’m afraid you don’t 🙁
The main driver here to Microdochium was the rainfall that ocurred at the end of August which kicked Microdochium off early in September. We then saw a second spike later in September, around the 19th, when we received our first rainfall of September for nearly 3 weeks. this ramped up the humidity and pushed on disease significantly. It also gave us some heavy dews, a wet plant leaf with little evaporation (because the winds were light) and so the plant stayed wet for long periods of the day, ideal for Microdochium.
I mentioned earlier that I have learnt a bit more about Dollar Spot on my travels and at this stage I have to thank the course managers I visited who allowed me to take samples from tees and fairways and look at them under a scope. Most of the affected plants I looked at showed mycelium present on the leaf tissue as shown in the image below…Quite pretty really..:)
The crowns of those plants however were largely healthy and this is important because it means the capacity for the grass plant to regenerate itself is still there. So fertilising to grow out the mycelium definitely is an option, much the same way as it is with Red Thread. This was really brought home to me on one course I looked at in Germany where they had bad Dollar Spot on fairways in mid-September, but when I visited last week the areas were much healthier (see pics of the same fairway areas below seperated by 14 days) The difference was a healthy input of granular N.
Of course the ability to grow out the disease depends on a number of factors, the weather being one of them and PGR’s being another. It would seem to me common sense that on areas affected by Dollar Spot, you should stop applying PGR’s in order to grow the disease out of the turf.
Wendy has kindly knocked up the yearly stats for 2014 including September and we can see that as a month it rated highly in terms of growth potential. The rub though is that this growth was only realised if moisture was present, and for many areas it was not. So GDD and G.P models, though useful do not show the whole picture in terms of grass growth potential and this is important because a lot of you guys are using GDD models to make PGR applications. What I mean by this is that if the plant is under moisture stress it doesn’t make sense to apply a PGR and further regulate its growth potential.
As usual I’d be interested in your feedback here…..
Ok long blog today, thanks for everyone’s feedback, weather data and comments, I do appreciate all of them and it enables me to keep this blog going…