Monthly Archives: June 2014

June 23rd

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Hi All,

As we pass the longest day it seems the year is just flying by and now the days jetstream230614are going to be getting shorter, kind of sad really because you think summer has only just started and we’re heading into autumn / winter….

Still at least the weather is playing ball, (unlike the England football team…my money’s on Costa Rica to cause an upset :) ) sunshine and heat-wise for most of us, so we can’t complain, even though the > 7-day forecasting isn’t, because of this split jet stream scenario…You can see how fragmented it is from the image right….

Although the jet-stream is still lying low, because of its lack of strength, no dominant weather systems have swung into the apparent void, so we haven’t had a repeat of the wet summer of 2012, yet…., instead we have a hotch-potch of weak systems controlling our weather, most of them high pressure-related so that means dry and warm for most. This week will be cooler in general though because of the wind direction dragging more cloud cover off The North Sea.

There are indications that it may change later on next week with the arrival of a low pressure from the north-west and if it does so that’ll mean rain and wind. That said there is a chance of rain this week, but yes you guessed it, it’s mostly continental rain, so totally unreliable to forecast…

General Weather Forecast

Ok Monday looks to be starting off dry, warm and settled for most of us, later on in the morning there’s a risk of showers breaking out along the east coast of the U.K and down to The Midlands, but these will be scattered in nature. (Bit like me really :))

Over Scotland we have a weak weather front carrying over from Sunday bringing rain showers and cooler temperatures than of late, but these will die out as we go into the evening. Ireland looks to have a grand day :) Winds will be light, from the north-west and temperatures in the low twenties in the Costa Del Sud of England, mid-teens for Scotland under that rain and cloud…

For Tuesday, it’s a similar picture but that weak rain front is set to bring some scattered showers over Ireland and the U.K, principally along the east coast but they could push inland during the day. The wind is set to swing round to the north-east, but they’ll still be light and moderate for most, perhaps a tad windier over Scotland. This will also peg back the temperatures a little, high teens the order of the day for most, this will be a theme for the week, cooler than last for sure.

For mid-week, we have a dry picture for the U.K, but for Ireland there’s a rain front stuck over it for the day. At present, it’s projected to affect central Leinster / Munster in a line drawn up from Kerry to Dublin with the west escaping the worst of the rainfall. Later on into the evening and overnight into Thursday this rain consolidates over Ireland to affect most areas. Elsewhere it’ll be another dry, hazy day with warm(ish) temperatures and light north-easterly winds.  Scotland will remain under the influence of that weak low pressure system, so cooler here under that cloud.

By Thursday we have a consolidated rain front over Ireland and there’s a chance it may drift eastwards to affect Welsh coasts through the morning, but for the U.K, it’ll be another dry, hazy day with light easterly winds and more cloud cover, courtesy of some ‘Haar’ coming off the North Sea. Haar means cooler as well for the U.K, mid to high teens under that cloud cover. As we round out the day, that rain over Ireland will become localised to the north / Donegal.

For the end of the week we still have that rain front sitting over Ireland and not going anywhere fast, that’s a consequence of a non-existent jet stream, once you have a weather system over you, it doesn’t move anywhere quickly….Friday (into Saturday) represents the highest probability of rainfall for the south of England and The Midlands courtesy of continental rainfall, so you may see some rain during the day down there, but as it’s from the continent, you know the craic by now…unreliable and hard to forecast….It’ll be cooler as well because the wind swings round to the north-east and drags more cloud cover off The North Sea.

Next weekend looks to be a bit mixed because of the risk of rain from the continent, but that may easily change sitting here at my desk on a Monday and typing this. At this stage we have rain affecting the south of England early doors on Saturday and possibly eastern coastal areas up to The Wash but no further. West and north of this rain threat it looks dry, but dull and cool because of that Haar effect. So if you’re off for an early summer break on the east coast, it won’t be anything to shout about…If you have a choice, head west :) Sunday looks better though, still cool with that northerly wind, but brighter so temperatures should lift into the high teens I’d hope.

Weather Outlook

So how are we looking slightly longer-term, any chance of the weather picture changing ?

Yes I think there is, but if it does it won’t be till the latter part of next week. Longer-term (10-day) projections are showing a strengthening of the jet stream and this should move weather systems in from the west if it does come to pass…..So for the start of next week we look to have more of the same, settled weather, dull with a risk of continental rainfall cropping up, especially for the south of England. If and it’s a big ‘IF’ the weather does change as predicted, you’ll see a swing round in the wind direction from mid-week onwards to a more north-westerly aspect and this will increase in intensity as we close out next week to bring stronger winds and rain for many by the end of next week / weekend…We’ll know if this change is due to take place this time next week….

Agronomic Notes

Ok, things are pretty settled at the moment out there save for some plant stress from the  temperatures and lack of rain over the last couple of weeks. Nothing major and with cooler weather this week and some well-placed hand watering, I’d expect areas to tick over nicely.

Nutrition-wise most of you will be into your regular foliar applications of nutrient, PGR and the like and I see no reason to change this agronomically from a weather perspective..

Disease-wise we’re into the summer disease spectrum now, and top of the list will be Fairy Rings because of the warmth and humidity of late.

Out walking at the weekend, two things struck me, firstly that I’ve never seen so much grass in the fields and verges as I have this year and farmers Hay crops will certainly be impressive. This is of course due to combination of the very wet May we endured and then the heat over the last 2-3 weeks. Outfield areas are just starting to go under drought stress now due to a lack of moisture (in most areas, Scotland excepted) and so that means the growth surge is past and it’s just a case of keeping things neat until the rain arrives. Hopefully you’ll have got these regulated before this period so the plant is able to conserve moisture and nutrient and stay healthier, longer into a dry period.

Fairy Ring mycelium covering roots and sand particles

Fairy Ring mycelium on Poa roots..(White Codwebs).

The second thing that struck me was the amount of Mushrooms and other fungi around in the hedgerows and this brings me onto Fairy Rings. Perhaps the least-damaging of our turf diseases (unless you have thatch collapse that is) but it still has the potential to take grass cover if the area is left to dry out and / or ammonia builds up under the turf canopy. Superficials in my experience are the worst for this because they come in very quickly….Now we’ve covered Fairy Rings before in terms of treatment, but I’ll go over it again briefly anyway, however before I do, it’s worth noting that their presence is telling us something. Now it may be on parts of a green or on certain greens in particular, but it normally indicates fibre build-up, not always, but most times, so it’s worth noting where it occurs (on a green) and on which greens because these will need more direct management from an aeration perspective in order to keep O.M in chechydrophobicityk.

If you are going to treat Fairy Rings, then the best way (IMHO) is to take a core out of the ring, lay it on its side, drop some water along the profile and look to see if an area ‘beads up’ the water droplets (see image right) This may indicate localised hydrophobicity courtesy of the presence of the fungal pathogen. This is key because in order to gain effective treatment, you first need to ascertain the depth that the pathogen is at work. If it’s in the surface of the profile then mixing Azoxystrobin with a wetting agent (to disperse the A.I uniformly through the surface fibre) will work well, with application followed by just enough irrigation to get the product mixture off the leaf and into the surface. If the depth of activity is deeper down the profile, then before treatment it’s a good idea to micro-solid tine at close spacings to a point just above the activity zone before you apply your mix of wetter and Azoxystrobin. (This assumes of course that the tankmix is compatible chemically, physically and biologically) You’ll also need more water to get the product down the profile into the zone of activity.

In my experience you’ll see the ring gradually disperse over time, it tends to happen faster the shallower the fungus is present, so Superficials clear up quicker than the more verdant green, Type II’s….Kate Entwistle has a little Fairy Ring ditty on her website, you can read it here

Longer-term you have to look at the cause of Fairy Ring and treat that, rather than the symptom and that means good organic matter management and topdressing to open up the surface of the profile to air and water movement.

I get a good deal of negative feedback from end-users about topdressing, not least in terms of the fact that their golf clubs view it as a negative and try to discourage the practice. It’s difficult to explain to a club secretary / Director of golf / General Manager, delete where applicable, why these types of management practices are so vital, because a lot of the time aeration and topdressing is designed to head off trouble before it occurs by efficient management of surface organic matter. So the heirachy will look at the turf and say “I can’t see an issue, we’re not getting complaints, if you aerate and / or topdress, we get complaints by the golfer and have to discount our societies / corporates accordingly”….Now I know some of you are / have managed to get round this within your clubs and for sure some of it comes from good communication but also what helps a lot is having somebody in charge that understands why these things are necessary. Of course if they’re not done, it’ll come back to bite you with softer greens, poorer drainage, poorer rooting, increased disease presence, etc..and sometimes not until this occurs will the message finally sink home, but of course by then it’s too late and requires a lot of remedial work to put right….frustrating and demotivating it is if you’re in that scenario…

So if anyone wants to share what they do / have done to get over this mental log jam, drop a comment or an email to me and I’ll share it with the masses…

That’s all for now…

All the best…

Mark Hunt

 

 

 

 

 

 

 

 

June 16th

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Hi All,

The ‘glorious 16th’ as it used to be known, a time of year as a kid that filled me no-fishingwith excitement because it’s the first day of the fishing season on rivers (closed season is from 15th March to 15th June), but in the old days, all waters, had a close season when no fishing was permitted. So today would have meant an end to 3 months of fishing abstinence and unparalleled excitement on my part, often manifesting itself (I’m ashamed to say) as an early departure from school to be on the river bank !  (Before you say it, that’s not why the blog is so late today !)

Well not a bad week, last week, warm, dare I say hot temperatures and some pretty hefty thunderstorms to boot. This week appears better than I forecast it last week, because the high pressure has strengthened rather than weakened, so that means settled and dry weather on the whole, but it’ll feel cool along East coasts due to the wind direction…

Quite a lot of feedback from my query regarding TE usage and efficacy, with the majority of replies (by comments, emails, etc) supporting the contention that higher rates of TE are required nowadays than previously to achieve the same degree of plant growth regulation.

Ok onto the weather, so how are we looking for the rest of the week / coming weekend ?

General Weather Situation

The biggest factor this week is the wind, or more specifically the direction of the wind which will dictate daytime temperatures. Since Saturday morning it’s been coming from a north-easterly direction and that means it’s a cool wind because it brings cloud cover in from The North Sea for many and this pegs temperatures back quite effectively. So the west and south will see more of the sunshine, certainly earlier in the week (and that includes Ireland). Where the wind is light and cloud cover breaks, temperatures should push up into the low twenties, where the cloud cover remains, it’ll be nearer high teens and on eastern coasts, you may pick up some rain / drizzle in the Haar and it’ll feel cool on the whole.

For many this week Monday will be the coolest day and from then on temperatures will pick up as more breaks appear in the cloud, so a really simple forecast for this week. Most places will be dry, warm and sunny if the cloud cover breaks and a little on the cool side especially earlier on in the week if it doesn’t. The wind will be mainly from the north-east / north for most of us but later in the week it should moderate and that’ll allow temperatures to pick up.

Rain I hear you say ?, nope save for some drizzle off The North Sea and a weak rain front coming into the north-west of Scotland on Friday, it’ll be a dry weak for all of us. Will it last to the weekend ?, will it heck, as that northerly airstream is looking to pick up cooler, wetter air for Saturday, so a drop in temperatures and rain is on the cards, particularly for Scotland and the north counties of Ireland and England on Saturday / Saturday night for the latter. Further south and west, it’ll remain warm for Saturday, but into Sunday that cooler air will sink south accompanied by an easterly wind and this is set to affect most places, dropping temperatures back by 4-5ºC….so a mixed weekend is on the cards depending on where you’re situated…

Weather Outlook

We look to start next week with a cooler, slightly unsettled feel to the weather with a chance of moisture particularly in Scotland and the north-east of England. Next week is finely-balanced between the low and the high and it looks as though initially a new high may push temperatures back up again after the weekend but I think there will be an increasing chance of some rain appearing from Tuesday next week….

Looking at the projections there’s a crafty little Bay of Biscay low set to develop in the early part of next week and if this is so, it’ll bring in wet air from the continent to the southern half of the U.K and Ireland from Tuesday onwards. This rain may hang around through to Thursday next week when things start to settle down again as a weak high pushes the low away. As usual that low pressure is slow moving so it may mean quite a heavy hit of rain for the south and Ireland if it manifests itself.

Agronomic Notes

This week I’m going to cover a topic that’s slightly contentious, that of overseeding…

If I had a pound (or a euro) for the times I’ve heard this response, I’d be a very rich man…”I overseed for sure, sometimes you can see a great take, but a few weeks later nothing” Usually the reason given is cutting height during the season, i.e you have to wait till we get good temperatures to aid speedy germination, but by then you’re at summer cutting height and that hinders seedling establishment. Whilst I’m sure this is a valid contributory factor, as are summer play levels,  I’m beginning to think they aren’t the main barriers to achieving effective establishment of seed.

Before we get into specifics, let’s just consider what we’re trying to achieve by overseeding ? Obviously we’re looking to add a new grass species / cultivar to an existing sward, but what is our objective ? To tick a box and say I’m overseeding to try and encourage ‘finer grasses’, blardy blah and thereby keep yourself or ‘the powers that be’ content ? …maybe….

Often we’re trying to introduce a different species / cultivar in an effort to make the overall sward ‘better’…but what is ‘better’ ?

In a golf green scenario, the objective is to give balance to the sward, reduce the homogenous nature of its composition and thereby impart ‘better’ sward characterstics…On a sportsfield or golf tee, the objective is often different, maybe better wear resistance and / or playability.

One of those key objectives in this day and age of ever-increasing legislation is better disease resistance….For example introducing bentgrass into a Poa sward will definitely give benefits in terms of reduced disease pressure from Fusarium, but before we look at how best to achieve this, shouldn’t we ask ourselves, why the bent isn’t there in the first place and why the current grass species (in this example Poa) is ?

Ultimately a grass sward will compromise a mixture of species, some more dominant than others, but it’s a natural situation which we manipulate un-naturally, both culturally (with cutting height, aeration, irrigation) and chemically (with PGR’s, fertiliser, etc). If we just overseed into an existing sward without changing the management practices I reckon it’s tantamount to p***ing in the wind, and will achieve little or nothing. First we have to understand why the existing sward comprises of the grass species that it does. Next we have to assess if its possible to change any or some of these factors to achieve a change in grass sward composition. We then have to change the ‘ground conditions’ before we introduce our chosen grass species.

I say ‘chosen grass species’ because at this point most of us will consult ‘the list’ of cultivars and assess which ones have ‘the best’ ratings, but that in itself isn’t really a guide as to whether this applies to your situation or not because every turf scenario is different. The geographical location, fertility regime, pH, PGR usage, organic matter levels, etc on the trial ground will be every bit as individual as your golf greens or sports pitches and the chances that the two are similar are remote in my way of thinking….So just because it says in a list that one cultivar is ‘better’ than another, it doesn’t mean that that difference will necessarily transfer itself to your situation. I saw some bentgrass plots recently sown down last autumn and if you look at the brochure and trials ratings vs. the reality in the plots, the two couldn’t be more dissimilar.

So where am I going with this discussion ?, well trialing cultivars in your scenario is the only way of truly seeing if one is better suited to it or not than the other…obviously this isn’t straight-forward, but it is worth it rather than just going through the motions..

The biggest barrier to effective overseeding in my humble opinion (but not the only one) is surface organic matter, I hesitate to say thatch because most people will say “I haven’t got thatch on my turf surfaces”, taking thatch to mean excessive organic matter. Surface organic matter doesn’t have to be excessive in depth (> 12mm say) to be an effective barrier to overseeding. If it is not adequately integrated with topdressing then even if it’s only 8mm, there’s no way that the seed will get beyond the seedling stage.

bridged

I don’t think I’ll overseed this year then…..

The easiest way to see if your surface is suitable to overseeding into is to take a plug, say 40mm deep and run a knife up the plug until you reach the bottom of the fibre layer. Lightly compress this between your thumb and forefinger and measure it. Then try and pull the surface fibre apart and look at the rooting characteristic. If it takes alot of effort to pull apart, chances are that the surface fibre isn’t adequately integrated with topdressing and furthermore, the roots will be bridged sideways because they physically can’t develop a root through the surface fibre layer.

So ask yourself, if the existing, established grass species has a rooting characterstic like this, what chance for a new seedling to develop it’s first adventitious roots  through the surface fibre layer ? Little or none I’d say and maybe that’s why sometimes you see that initial ‘take’ of seed and then it disappears, because it cannot develop a good enough root system to support a growing seedling and so ‘checks out’, over-run by plants that have adapted to the conditions better. (Usually Poa on a golf green)

So the best overseeding practice has to rely on overcoming this impediment aOverseedingnd increasingly I think this is hollow coring or solid tining because it removes (one way or another) the physical barrier to establishment. I saw this graphically illustrated last week (see image right) on a number of courses, not only does it provide a perfect environment for the new seed to develop in, but it also shelters it below the canopy and more importantly, the cutting height. With more vigorous species, like Ryegrass, I’m sure that slit seeding using machines like the Vredo can achieve the same result, but with Fescue or Bentgrass, I remain to be convinced that this is as effective a solution.

I mentioned changing management practices earlier and of course one of these is PGR usage (that old Cheshnut I hear you say) because once you’ve started down the road of introducing new seedlings into a sward, it doesn’t make sense to try and retard their growth with a growth regulator, so there’s a compromise that needs to be made if and when you embark down this road. This is of course dependent on the species you’re introducing, if it’s Ryegrass then it is less-affected by TE usage and so applying once it reaches the two-leaf stage appears fine, but is this the same for Fescue or Bentgrass ?,I think not because they are affected more by the use of TE. You could argue that TE affects the existing Poa more than the newly-established seedlings of Fescue and Bent, but I’d like to see some work on this that proves it. Certainly using TE before overseeding is a proven management tool because you reduce the competitive advantage of the existing sward components prior to overseeding.

Food for thought I hope, sorry for the late posting of this blog this week…

All the best
Mark Hunt

 

 

 

 

 

 

June 9th

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Hi All,

Blackbird

Can I have some more please ?

As I sit and type this blog, I’m watching an adult male Blackbird feeding his young on my lawn. The young Blackbirds are bigger than the adult and the food is on the lawn right in front of them but, despite that, they still call out to be fed… They must be the bird equivalent of modern-day teenagers i.e. very demanding and totally feckless… :)

 

 

 

After a weekend of two halves, where we had a muggy Friday night accompanied by thunderstorms, and heavy rain on Saturday then the heat of Sunday, this next week is looking a little similar with some rain to clear through in the early part of the week before some better drier and warmer days from mid-week onwards. So what’s changed? Well the jet stream is still split in two as the graphic below shows: with a northern section flowing over Greeenland and a southern section (the one that affects our weather) sitting over the U.K. The change is that the southern section has shifted higher and that’s allowing warmer air up from the continent.

Things aren’t normal though because it should be flowing in one segment, not fractured into two and that’s going to affect our summer weather for sure (how though I can’t be clear at this stage)…

hgt300

Image courtesy of NetWeather

General Weather Situation

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Image courtesy of Gywnn Davies

Well currently we’ve got some rain moving across Ireland and the western half of the U.K. and where that rain encounters warmth, there’s a likelihood of some thunderstorms for a time. I’m grateful to Gwynn for sending in this image showing some pretty sinister flat Stratus clouds signifying rainfall and an imminent storm. Through the morning, this rain is set to move eastwards across the whole of the U.K. but amounts shouldn’t be too high, unless you cop a storm that is… Scotland looks to start dry, but that rain reaches the borders by early afternoon and then you’re set for a wet end to the day. Temperatures should be pleasant, high teens to low twenties and winds will be light and from the south.

For Tuesday, we still have that mass of cloud circulating over the U.K. and Ireland, but through the morning it’ll push northwards into the north of England and Scotland, leaving the south of England dry. Ireland and Wales look to stay pretty wet most of Tuesday as that rain gradually moves northwards, but continues to affect western coasts. Temperatures will be high teens for most areas, maybe into the twenties in the Costa Del S.O.E (South of England) Winds will be moderate to blustery and from the south / south-west.

Wednesday is a much drier picture for most with that rain, now much lighter in intensity, sitting over the north-west coast of England and Scotland and slowly clearing through the day. Elsewhere it should be a much better day once the cloud has thinned, with nice temperatures up in the high teens – low twenties and light-moderate, westerly winds.

Thursday sees another dry day for most with the only fly in the ointment being a weak rain band that’s due to affect the west coast of Ireland during Thursday morning and then move into Scotland by the afternoon, giving a potentially wet end to the day there. South of say, the M62, it should be dry, warm and a very nice day indeed, with temperatures pushing into the low twenties, with a light-moderate westerly wind.

Closing off the week we potentially have an east-west divide as that rain is due to push south and affect the east coast of Scotland, England and Ireland during Friday, but since the rain band is narrow, it may easily miss us completely and just slink off into The North Sea. West and south of this, it looks another lovely day, with similar temperatures and winds to Thursday, maybe a little windier.

So how does the weekend coming look ?

Well we have high pressure in charge, so ordinarily I’d say it looks like being dry and warm, however because of the location of the high pressure system it’s likely to pull cooler air down from the north, so first off, the wind direction will be northerly. Secondly, some of that air will be moist, so it’s likely that we’ll see rain over the weekend, with a chance of showers over central areas on Saturday afternoon and again on Sunday, this time they look to be more westerly-orientated. With more cloud cover and a light northerly wind, temperatures will be down on the week previous, with high teens the order of the day. So sunshine and showers looks to be on the menu for the weekend.

Weather Outlook

This weeks nice warm weather is courtesy of a high pressure system, but next week this high looks like being squeezed between two low pressures and they eventually look set to push it out of the way completely, so I expect an unsettled week, next week. Rainfall-wise this means a return to rain at the start of the week, with potentially heavy rain from mid-week onwards, next week. Temperatures will still be reasonable, high teens I think and not particularly windy as no one system is set to dominate next week.

 Agronomic Notes

Well quite a lot to write about this week…

Growth Characteristics and the Growth Potential Model

From this point in the year, I’m going to start talking more and more about Growth Potential (GP), rather than Growth-Degree-Days and that’s because Growth Potential is a more accurate predictor of growth during the summer months as it takes account an optimum temperature for growth, denoted by a Growth Potential figure of 1.0 (the maximum it can be). Above that optimum temperature we know the plant begins to become stressed and so growth begins to decline, the Growth Potential Model takes this into account, Growth-Degree-Days does not.

A quick lesson, the Growth Potential is given by a value between 0 and 1.0, with 0.0 – representing no growth and 1.0 – optimum growth. The difference between Growth Potential and GDD is that with increasing temperature in the summer, GDD will keep on showing an increasing figure, whereas Growth Potential will not because it works on an optimum temperature for grass growth. For instance we know that once we get to 26°C +, the growth rate of Poa annua declines significantly, above 30°C it stops growing full-stop. So I think it makes more sense to start using GP to talk about growth once we start to build temperatures in the late Spring / Early Summer. I know a good few of you have been using GP for awhile now, there’s a link to a good paper explaining growth potential here

If you look at the last week or so, you can see we were sitting on around 0.55-0.7 from a growth potential perspective, but come the end of last week and specifically over the weekend, with the arrival of higher day and more specifically night temperatures, that figure has rose to close on 1.0. What this means is that according to the Growth Potential Model (GPM), the grass plant is growing at an optimum rate. A change in the GPM from 0.6 to 1.0 means a 66% increase in growth rate and an accompanying significant flush of growth. What’s more with the heavy rainfall (for some) last week and (for many) on Saturday, the grass plant is succulent, the leaves have a high water content and so appear soft and puffy.  This will gradually correct itself as high daily E.T. lowers the grass plant’s moisture content. If the plant is succulent, don’t go out with an aggressive verticut until it has lost some of that moisture else you’ll see alot of damage.

Growth Regulation by Trinexapac-ethyl (TE)

When I attended the GCSAA show this year, one of classes I sat in looked into the characteristics of Poa / Bent greens and the discussion moved onto the use of PGR’s. One of the Superintendents raised the point that his application of TE no longer provided the same growth regulation than it did when he first started using it. The lecturer dismissed this, however when asked for a show of hands in the class if other supers had seen this, it was significant and the lecturer was non-plussed.

It’s been mooted for some time now that one of the issues of this performance drop off relates to the breakdown of the TE molecule with temperature, the warmer it is, the faster this takes place, the less time it’s effective for, so one piece of advice is to shorten your frequency of application of TE when we get to the summer months.

However I believe we’re seeing something else. If you think about it, we’ve been applying TE to areas right back to the Shortcut days and the area that has received the most applications, on a regular basis, is fine turf, golf greens. Tees, approaches, fairways and sports fields receive less frequent applications, mainly due to budgetary constraints. (This where we differ from the U.S. which has much more frequent applications of TE and in fact pesticides in general on outfield turf)

Applying TE on a regular basis in my mind constitutes a selection pressure on the grass sward because we know it doesn’t affect all grass species / biotypes the same. So to my way of thinking, the grasses that is affects more, will grow less and the grasses that it affects less, will grow more. Over time, the grass biotypes less-affected by TE will surely dominate, now that might be a particular Poa or maybe Bentgrass, but either way I’m sure it’ll happen if the selection pressure is constant. So eventually you’ll end up with a sward of biotypes that are less-sensitive to TE and therefore you’ll have to apply more TE to achieve the same effect. I have no proof of this theory, it just seems logical to me.

So I’ll put out a question to you and I have to be mindful here of label rates,  so I suggest you are also :)

“Do you have to apply at a higher rate of TE than you used previously to gain a growth regulatory effect ?”

Now going back to Growth Potential, it figures that when we see an almost 66% increase in growth potential to a near optimum value, then you’re going to have to apply a much higher rate of TE than normal to gain adequate suppression of your grass sward. Looking at the the GP model, it’s clear that the trigger in this growth flush is night temperatures, if they are high, and by high I mean > 15ºC, then you can expect a growth flush at this time of year.

Of course grass growth isn’t the only parameter affected by the high temperatures and rainfall, disease activity is also significant at present and has been for awhile now as I discussed last week. Keep an eye out for Microdochium, it should grow out as fast as it appears, but sometimes that’s a tricky call.

After the wet winter and late Spring, I expect Take-All to be an issue on some high bentgrass content swards, specifically. It’ll only rear its head when the plant goes under E.T. pressure, like we saw yesterday when we had strong winds and high temperatures. In this scenario if Take-All has damaged the grass plant roots it appears un-affected until it needs those roots to replace significant moisture loss due to high daily E.T. rates and then you see the damage in the sward.

Looking ahead we only have this week before temperatures drop off again at the weekend and the weather becomes more unsettled, so things should settle down a bit thereafter.

All the best…

Mark Hunt

 

June 2nd

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Hi All,LongMyndd

Just back from a mini-break in the camper on The Long Myndd in Shropshire and for once the weather played ball. It’s a beautiful part of the English countryside for those of you who don’t know it . I took an early morning run to the top with the mist rising off the moors and Peregrine Falcons overhead..good for the soul…

After over 4″ of rain in the last week or so, this dry spell of weather has been a god send to get areas back under control, but unfortunately it isn’t going to last, as a new set of low pressure systems is due to drop down this week and return us to more unsettled weather. Again the characteristic of this rainfall will be a low pressure system that keeps circulating above us, rather than moving through quickly, so that means plenty of rain, particuarly from mid-week onwards. :(

Just before you throw your toys out of the pram, I can offer a ray of hope…I think we may pick up some warm and dry weather after next weekend, if the weather patterns stay on track…

General Weather Situation

Monday sees a fine start for many areas after a pleasant weekend with some real heat yesterday in the sunshine.  It’s not dry everywhere though, as the west coast of the U.K has a band of rain stretching from the south-west of England right up to the tip of Scotland and this is set to move slowly eastwards bringing rain for many areas this afternoon and finishing off with a wet evening on the east coast. Ireland looks to have a dry (ish) Bank Holiday as that rain cleared sooner than forecast. Temperatures will start off nicely under the sunshine away from the west, but as the rain and cloud arrives, they’ll drop to mid-teens for most of us. Winds will be light and from the west.

Overnight into Tuesday we have another band of rain crossing Ireland, as the weather takes on a familar unsettled theme and this will bring showers and / or longer spells of rain to many areas on Tuesday. These will be particularly prevalent in the afternoon, with the heaviest rainfall falling over Scotland and the north of England, but most places will see some rain on Tuesday, Temperatures will stay at their mid-teens, and the night temperature will be mild, again winds will be light. Ireland looks to stay reasonably dry until the afternoon when some of that rain moves into Connacht and Donegal.

Wednesday sees that low pressure sitting straight over us, so a very wet day for many with the rain again becoming heavier in the afternoon and it’ll feel noticeably cooler to boot with low teen temperatures. Winds will whip up as well and although they’ll still be westerly, they may swing round to the north-west for a time. It’s difficult to say whose going to get the most rain, but at present it looks like The Midlands north up to Scotland, will cop the worst of it, with the north-west of England and Wales in the firing line as well. (Not a great week for the Isle of Man TT) For Ireland it looks potentially heaviest over Leinster through the course of the day.

Moving onto Thursday, that rain front is looking to sit above a line drawn across the U.K from Bristol to The Wash and as we move through the day, it pushes northwards clearing as it does so..Temperatures should pick up a little to mid-teens and towards the end of the day, the sun should come through. South of this line and over Ireland, it shouldn’t be too bad a day really with broken sunshine through the day and little in the way of rain.

It’s a reverse situation for Friday with a dry start to many areas except the far north of Scotland where that rain is slow to clear, however further south we have some more continental rain pushing into the south coast of England at daybreak and set to move up country through the morning. North and west of this should start dry, but by late morning this rain consolidates and moves into Ireland and most parts of the U.K, though it shouldn’t reach Scotland till the evening.  It’ll feel noticeable warmer on Friday as the winds swing round to the south, with temperatures into the high teens in places. Now remember what I said about continental rain, it’s very hit and miss and hard to forecast, so it has the potential to change.

So how is the weekend looking ?

Well initially it looks very poor for first thing Saturday morning, with a very heavy band of rain coming off the continent. This could change though, but even if it does arrive, it should clear through quite quickly, so if you’re having a lie in, you make wake up to some sunshine in the south as the rain clears up country. Ireland and Scotland look to start dry, but then rain is set to move in during Saturday morning and give a pretty wet affair for the rest of the day. Once the rain has cleared in the south and Midlands, it should be a nice day in the sunshine with some decent temperatures into the twenties I think…

Sunday looks pretty unsettled with again more rain off the continent, this time it’s projected to move up the east coast during the day, but remember this is continental rainfall, so my advice is look at your Weathercheck forecast on Friday evening to see if you’re in the firing line for rain over the weekend. Sunday looks better at this stage for Ireland, but for most it’ll be a little cooler under that cloud and rain. The wind direction over the weekend will be all over the shop as the low moves through, so it’s likely to be a four winds in one day job.

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 Weather Outlook

After another unsettled week this week, it looks like next week could be a good deal better as high pressure is projected to take charge and so that means drier and warmer for many. The week will start off unsettled as that low will still influence the weather for Monday, so rain for many places, but from thereafter we look to be a lot better with warmer, drier air on the way. If this pans out, I expect very good temperatures for at least the south of the U.K by the end of next week, but better for most of the U.K and Ireland overall.

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Agronomic Notes

Disease Activity

With last week’s rainfall following warm weather and then some warmth this weekend, it’s not suprising that we’ve seen another fresh outbreak of Microdochium (Fusarium by another name :)) for many places, but I’m hoping that with the dry interlude, that pressure has dropped a little. Expect to see it re-appear this week with the arrival of more rainfall.

Microdochium in the growing season is always a hard call between spraying or not spraying. Personally I prefer to try and grow it out and keep the plant hard by use of phosphites, elicitors and iron products, rather than spraying a fungicide. Of course this depends on your grass species and your rate of growth. If you have dense, perennial Poa annua, then the disease pressure is much higher than a sward of Poa / Bent. This is because the denser the sward is, the higher the surface organic matter content and the more favourable therefore for Microdochium.

For this reason it makes sense to try and introduce conditions more favourable for bentgrass establishment and that means lots of topdressing to dry the surface out and potentially overseeding, but to be honest I don’t get much positive feedback from the latter. (Do you?)

PoaBentDisease

Microdochium in Poa plants in a Poa / Bent sward

Part of the reason for this is definitely surface organic matter content, i.e if you have a dense layer of surface organic matter, (it doesn’t have to be excessively deep) then I believe it’s very difficult to get bentgrass to establish by way of overseeding. On the flipside I’ve seen greens which have had a lot of cultural work done to lower surface organic matter content, in combination with good levels of topdressing, and the bentgrass ingression has been excellent, without any overseeding. Having a mix of grass species on your surfaces, whether we’re talking greens, tees, fairways, sports pitches makes a lot of sense to me because you are reducing the potential vunerability of your sward to disease.

Take the current conditions, if you have a very high Poa content on your surface, you will have a much higher susceptibility to Microdochium, if you have a mix of species, you’ll still see some Microdochium, but the pressure will be lower and this can make the difference between having to spray or not at this time of year.

The lesson is there in nature, monoswards do not occur naturally, man has engineered them this way. Coffee, bananas and wheat are all examples of intensive crops, farmed as monoswards, with inherently low genetic diversity and now these crops require very high levels of pesticides to produce significant yields. Indeed the research now is orientated around trying to introduce more genetic diversity into the above crops to naturally lower their disease susceptibility.

So if you can introduce a mix of grass species into your sward successfully and I recognise it’s a very big ‘IF’, then you will reap the benefits in the future.

GDD Summary

How did May shape out from a growth perspective ? Well a lot better than April although we still had some peak and troughs as those cool, low pressure systems moved through. You can quite clearly see their influence in the graphic below…

GDDMay2014chart

The reason May has been a better growth month on fine turf surfaces is because night temperatures increased from around the 6th, 7th May and this gave us some much better daily growth rates (GDD figures between 6 and 8 per day, rather than 2-4). We also got some unwlecome growth flushes in May, around the mid-part of the month and unfortunately at the end of the month which coincided with the Bank Holiday weekend. These flushes came also came after significant rainfall so that made getting the growth under control doubly difficult.

As a month, May checked out pretty well compared to other years, very similar to 2011 and 2012, both good growth years, see graphic below….

GDDmonthlycomparisonandcumulativeJantoDec2010to2014image

Looking at some other data I’ve been kindly sent, it appears some parts of the continent had a much warmer May than we did, as Denmark checked in with 245 total GDD, vs. 194.5 from The Oxfordshire and 218 GDD from Long Ashton (Cheers Ian, Sean, James respectively)

Leatherjackets and Cyren usage

A couple of weeks ago, I reported that you were only allowed to apply one application of Cyren per year because that’s what it says on the product label. I’m grateful to my colleague, Mark De Ath for pointing out that the CRD approval notice actually states that you can make two applications per year. This is particularly prevalent at the moment because we’re still seeing massive populations of Leatherjackets on sports turf and with the wetter weather this week, it’s ideal to apply and get the product into the soil profile.

That said, check your Meteoblue Weathercheck for the daily rainfall total first because if it’s higher than 6mm, I’d wait as you don’t want the product to be pushed down to far, too quickly, into the soil profile and of course high rainfall will also dilute the A.I in the soil significantly. The approval notice is available for download here

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Ok that’s all for now, grin and bear the rain later this week because the sunshine should be on the way next week… :)

Mark Hunt