As predicted last week, I missed my blog slot on Monday as I was attending my first European Turfgrass Society (ETS) field trip in Monte Carlo. It was quite an eye-opener on lots of fronts, firstly Monaco, what can you say, on the positive side, the weather and normal people were nice, on the negative side, every scrap of space is built on, underground, sideways, upwards, whatever… for me it’s one big chicken coop. That yacht in the background cost a cool £62 million, but the good news for any of you who fancy it, is that it can be hired for a snip….well I say a snip, it’s actually €399,000 a week + of course expenses, whatever that might be ! 🙂 😛
So ok I can see you’re looking at this picture and thinking what a jollie Mark’s been on, lazy so and so, couldn’t be a**ed to do his blog, too busy sitting on the front sipping a lime Cachaca, people watching (ahem), whilst you guys battle the highest disease pressure we’ve probably known….. That’s not an accurate version of events, so what is ?, what do ETS do ?
Well they organise very good field trips and conferences on turfgrass research and I have to say after my first experience I’ll be going back because it was invaluable in terms of sitting with researchers from the U.S, southern and northern Europe and talking turfgrass, that’s what floats my boat, big time…
If you want to learn more about them, follow the link here , but here is a flavour of the topics covered…
I’ll be chatting through some of what I learnt in the agronomic notes, but the weather awaits and after having one lad telling me it was 18°C as he drove into work this morning and close to 100% humidity, it needs some discussion….
General Weather Information
As you can see from the image above, we are still in the grips of a warm peak in the jet stream and although we’re receiving welcome rain in most places, this combination of weather is making life tricky from an agronomic perspective, so what’s in store for this slightly shorter than usual weather forecast ?
Looking to the rest of Wednesday, we have a heavy band of rain pushing into the south-east corner of Ireland (Munster / Leinster) this evening and that will mostly affect the east coast of Ireland overnight, but it will also push into western Wales and the west coast of the U.K as well later into the night. Elsewhere it’ll be a dull, misty, mild night (again) so not great from a disease perspective I’m afraid.
Moving onto Thursday, that rain band will stay in position overnight over Ireland and the U.K and if anything intensify for the morning rush hour, so potentially some more heavy downpours affecting the east coast of Ireland, particularly Munster in the afternoon. Temperatures will remain mild, high teens, low twenties even in the south-east, accompanied by a south-easterly wind. The rain affecting the west coast of the U.K will drift eastwards to affect the south coast, south-east and Midlands during the afternoon. Later on, a heavier band of rain moves into the south coast of England and rapidly pushes up affecting all of the U.K overnight into Friday. That rain will be heavy, particularly in the north, north-west of England and Scotland.
For Friday, we still have that rain affecting the east coast of Ireland, northern England and Scotland and I expect flooding here for sure. Further south it’ll start off dry, but a weaker band of rain will push into the south-west of England and move across the U.K during the morning / afternoon, so more rain, albeit lighter in nature than Thursday’s for many. Temperatures will be mid to high teens and again that wind will be south / south-east in nature, but much lighter.
For the weekend, it’s not looking too bad….Firstly it’s going to be dry, a little cooler, down to mid-teens, dull, light cloud cover, breaking towards eastern coasts first on Saturday and Sunday afternoon and the winds will be light. Can’t be knocked for early October, except the dew will be back I guess….
At this stage it’s looking like high pressure is set to build over the continent and bring back the Indian Summer for next week, so warm during the day (high teens I think) , cool at night (single figures, prompting the return of heavy dews) and dry, with light winds. Looking even further I can see a low forming in the south Atlantic that’ll push up, most likely for late weekend after next and this may bring back the unsettled theme to the weather mid-month.
Ok what to talk about, well it has to be…..
Last month saw perhaps unrivalled disease pressure for September, with very warm days, warm / mild nights and very high humidity, > 90% for alot of the U.K. (particularly The Midlands south..). To make matters worse, we also had periods of heavy, localised rainfall and very cold nights, down to 2°C in places and this really affected fungicide uptake and performance.
The GDD and rainfall chart below highlights the periods of the month when disease pressure was high ;
The same graph below highlights periods when uptake of systemic fungicides was poor because of cold nights, low GDD and hence low uptake potential of systemic fungicides.
So it was a real bitch of a month to be plain, periods of high growth potential when fungal populations were stimulated and applied fungicides were removed from the leaf over short periods of time followed by sudden drop off in temperatures when uptake of systemic fungicides was poor.
The latter generated a lag in uptake for root-absorbed, XMS (Xylem mobile systemic) fungicides, during which time the plant was un-protected and so disease got a hold. Examples include Tebuconazole, Propiconazole, Azoxystrobin, to name but a few. There was however another problem, just to really make life interesting…
Question – When is a Contact not a Contact ?
The answer is, when it’s a Contact Protectant…. I’ll explain…
At the risk of getting hauled over the coals by certain companies in our industry I’m going to tackle this subject, but a word to them first….any subsequent correspondence will be published in this blog.
Currently we have two types of ‘contact’ fungicides available to us in various products / formulations / concentrations / combinations from various companies, they fall into the following categories ;
These active ingredients remain by and large on the surface of the leaf and in so doing they affect pathogenic fungal mycelium and spores on the plant leaf surface. They are excellent protectant chemistries for use when the grass leaf is clean or during / prior to periods of dormant growth because their longevity is increased. (They are not removed as fast because the clip rate is low) These include Fludioxonil and Chlorothalonil.
The problem is they have “little or no systemic activity” (to quote one of the companies own literature from the agricultural market). So if you have active disease, (which can be either visible as scarring or if in the early stages, invisible to the naked eye) and you apply a contact protectant, you will not get good control of the disease because the fungus is already IN the leaf and your active is ON the leaf.
To get fast control of active disease (visible or invisible to the naked eye) you’ll need to apply a local penetrant contact chemistry and here we have just one active ingredient, that is Iprodione. This A.I will move from the leaf surface into the leaf itself and thereby control active disease and that’s the difference. You may also achieve control by applying a local penetrant systemic fungicide, again there are a few of these available.
In trying to clear up the confusion on this subject area, I’m not saying one type of chemistry or one companies products are better than the other, that’s not my purpose. They both have advantages and disadvantages, but the key is to understand the difference, understand where your turf is at and select the right type of A.I, regardless of company…
The problem is end-users are being sold products under the broad term ‘contacts’ and as such the understanding is that they will control visible disease quickly, but when they contain contact protectants, they will not, that is not an accurate description of their mode of action and it is not an accurate expectation from the end-user.
So we have a situation like we had last month, It’s mild, muggy and humid….Johnny Bloggs goes out to his greens, sighs as he sees how wet the plant leaf is, even though he’s already taken the dew off once, sighs again when he sees how much grass is in the box and then curses as he sees the first signs of active disease on his greens. So out comes the fungicide, let’s call it product A, with systemic and contact activity, except the contact features protectant-only chemistry (ies). He applies following the label recommendation and trots off home, content in the knowledge that he has applied the right product.
The next morning he comes in and the disease has got worse, pushed on by the high temperatures, humidity and dew. Ok he thinks, just a little lag before the fungicide kicks in. The next day the scars are growing, they’re much worse and on one or two of his problem greens, he has active mycelium clearly visible, how come ? he thinks, I’ve sprayed a contact and systemic fungicide ….. Not good, not good at all. Overnight the weather changes, we lose the high temperatures and it goes cold, so soil temperatures and growth drops, but the disease carries on moving because the systemic part of the product isn’t yet in the plant at high enough concentrations to achieve control.
What’s more it’s not going to get any better, any quicker, because the slow down in growth rate means less A.I is being taken up from the soil on a daily basis so the balance between disease populations and fungicide concentration in the plant is shifted in favour of the former. By this time a good % of the green is affected, enough for his members to start questioning why he hasn’t sprayed a fungicide or taken any other measures to control the disease.
It can then go a number of ways…..
- He can wait, confident that the systemic will eventually build up in sufficient concentration in the plant to achieve control. To make this judgement confidentally, he needs to look at the weather and see if the air / soil temperature and so uptake is likely to improve…This is a big balls approach, particularly if the members are kicking up, but ultimately it’s a balance between how much of the green is affected and how much pressure he’s getting…
- He might go back to the ChemSafe and repeat the application, with the same A.I’s and of course he doesn’t achieve any more immediate control than with the first application, plus he’s blown a lot of the clubs money.
- He applies a local penetrant chemistry to try and achieve control, this may or may not work by now, depending on how high the disease population has established, how conducive the conditions are for uptake and of course how quickly the chemistry is being removed from the leaf by cutting..
There are other factors in this complex equation, fungicide resistance and fungicide A.I microbial breakdown to name but two…
On the latter subject area, it was reported at the ETS that research work in Norway has shown that in certain situations (presumably where the same product has been applied year after year i.e poor fungicidal rotation) a specific microbial population develops that effectively feeds on the fungicide A.I, because after all these are often carbon chain compounds and that’s what some species of soil microbes feed on. (Actinomycetes for example) So the soil microbes break down the fungicide A.I and in so doing they effectively reduce the amount available for uptake by the plant leading to poor fungicide performance. I’ve read about this before with insecticides in the States like Nemacur, an organophosphate once used to control nematodes, but I’d never read about this ocurring with fungicides.
Now, I’m not saying this is happening everywhere, but it does again highlight the need to practice proper fungicide rotation, that is varying the products applied in terms of active ingredients. It also makes me concerned for the future when we will have less A.I’s available and so carrying this out will be harder to achieve.
I’ll end on a positive….At the ETS, there were two great presentations from researchers in Denmark and Norway, countries where I’d expected the attitude to be completely against pesticides and their use. This wasn’t the case, the presentations highlighted the political agenda present, which by and large was not based on factual evidence, “..not reality, just politics”…But to the contrary, these people had carried out excellent, applied-turf research to show how pesticides behaved in a proper rootzone, how little leached from that very effective grass filter system we all maintain and which A.I’s performed best in this scenario.
They had generated facts, facts that allowed them to make a case, an argument and in so doing, they had actually added a fungicide to the very small list available to the greenkeeper, totally against the political agenda.
Our industry needs more of this work, a lot more of this work if we are to make a case to the politicians / legislators, who make / shape our law. In the U.K, we have the Amenity Forum, a platform to have and take this discussion to the politicians, so we’re on the right track (good work by all those involved), but we need research, much more research, non-partisan in nature, to generate facts, to make our case, for our industry and thereby avoid being lumped in with agriculture.
Ok off the soapbox for this week…
The following GDD data for y.t.d, compiled by the ever-efficient Wendy, can be found at the links below ;
All the best…