Monthly Archives: July 2013

29th July

Hi All,

Market Harborough Town Centre – Saturday night
Photo courtesy of Neil at George Halls Cycle Centre

Red box shows Saturday evenings rainfall

As the weather continues to tilt between heat and moisture, we’ve had some pretty severe storm events over the weekend, none more so than in my home town of Market Harborough, where I recorded 53.7mm of rain falling over a 2 1/2 hour period on Saturday night, flooding the town centre and putting us on the national news !

This downpour was the result of heavy thunderstorms that moved up from the continent on Saturday afternoon and as such are pretty random in their manner. Apologies for not forecasting them last week, but Meteoblue had it right in theirs with respect to rainfall, though not the amount, hardly surpisingly !

 General Weather Situation

We have a weak low pressure moving off at present, that’ll keep the temperature down and continue the unsettled theme for the early part of the week, before heat builds mid-week and finally a new low pressure arrives for the end of the week / weekend. In fact it wouldn’t surprise me if we have a repeat of those random thunderstorm events towards the end of this week as well. Putting some detail on it, Monday starts off cool (ish), cloudy for most with a weak band of showers affecting the west coast of the U.K and the east coast of Leinster. Later on in the morning, those showers will intensify into a rain band that pushes across Ireland, heaviest in the the north and at the same time, rain will push up from the south-west of England to affect pretty much most of the U.K through the day, save for the south coast, maybe south of the M4 / M25 will miss most of it, but amounts will be pretty light anyway. The wind will be primarily south-westerly and temperatures sitting in the low twenties are to be expected. Overnight a band of heavy rain is due to push into the south-west of England, north west of Scotland and Wales, making landfall around 6 a.m. (ish) and then pushing eastwards to affect the south of England and south Midlands. At this stage it’s projected to track across in a line from mid-Wales to Great Yarmouth, so areas north of this will miss the worst. Ireland should see showers affecting the west coast initially and again these will push eastwards across the country during Tuesday. It’ll be noticeably cooler in this rain where you get it.

For Wednesday, more rain is projected to affect the south-west of England and Ireland, again pushing eastwards across both countries, but this time I think the rain will have a more northerly trajectory, so the south of England will miss the majority of it. (sorry). I expect the rain to be heavy along the south coast of Ireland, though mid / north Wales will also be on the receiving end later in the day, as potentially so will be Leinster. South and east of this rain, it’ll be dry, warmer, with temperatures pushing into the early twenties and with a light westerly wind. For Thursday, the first day of August, that rain pushes northwards into northern England and Scotland leaving a clearer day in the south and Midlands, where temperatures will rapidly push up into the mid-high twenties. For Ireland, Wednesday’s rain may intensify overnight into Thursday for the east coast of Leinster particularly, before clearing northwards during the late morning to be replaced by a new band of rain pushing along the west coast of Munster / Connacht in the afternoon. Friday sees more showers affecting Ireland, pushing in from the west coast during the morning. For the U.K, that northerly rain stubbornly hangs on over central and north-western Scotland, whilst further south it looks to be another nice day, potentially duller than Thursday, particularly along southern and western parts of the U.K. Temperatures will again be mid-twenties for most areas and the wind will remain south-westerly.

The weekend looks a bit mixed and unsettled as a low pressure pushes showers across Ireland and the west coast of the U.K. Further east and in the south, it’ll remain dry and sunny, but always with a chance of catching a shower, pushed along on that blustery, south-westerly wind. Later on in the day, there’s a chance of rain pushing into the far south-east corner of the U.K, if that’s so, it’ll bring some much-needed rain to Kent. Sunday looks by far the best day of the weekend for the U.K and Ireland, clear, dry and bright for many and temperatures will push up a little to the low-mid twenties again, so very nice indeed !

Weather Outlook

As we move into August, I can see high pressure looking to re-exert its influence for next week, so that means a drier outlook, with steadily building temperatures, pushing into the mid-high twenties potentially. It could be a very nice week to be on holiday in the U.K or Ireland :) Looking further ahead, I think there’s more unsettled weather on the way for the middle of the month, but that’s a real Mystic Meg job at this stage.

Agronomic Notes

A little bit thin on the ground for this week as I have been away, but here goes..

Plant Nutrition

First and foremost, I think it’s a case of more of the same, that is, keeping the plant ticking nicely along with low amounts (5kg / N / hectare) of foliar N, tank-mixed with chelated iron, to minimise stress on the plant. As mentioned previously, this time of the year is critical for the development of Anthracnose disease and chatting to Kate this morning, she confirmed that she’d already seen samples of foliar blight Anthracnose, so it is out there. This link from Kate (Ta chuck) was added to last week’s blog shortly after I completed it, but just in case you may have missed it, here it is again Link about Anthracnose

Plant Stress

After July’s hot weather, it’s not surprising that we’re seeing a lot of stressed Poa out there, it doesn’t like the heat and particularly on the tighter, reptans-dominated swards, it has a higher organic matter level and this is key to the problem. Poa annua var. reptans is by its nature, a dense, highly-tillered, grass plant, and with this density comes localised, surface organic matter. Organic matter and heat don’t go, primarily because organic matter will heat up much faster than say a soil and so if you have a concentration of organic matter in the surface (as we will have on high Poa-content swards), you’re going to have elevated temperatures and therefore elevated plant stress. Not to mention the fact that the organic matter is also hydrophobic (by its nature) and so hard to keep consistently moist, without the use of surfactants.

PersonalIy, I think there’s a lot of greens out there at the moment with higher than desirable surface organic matter and we can trace its legacy back to 2012. The cool, wet summer, last year caused a reduction in microbial activity (lower temperatures and low oxygen content soils due to frequent waterlogging) led to a slowdown in organic matter breakdown and therefore net accumulation of fibre. Dovetail that in with the fact that a lot of aeration and topdressing activities got shelved for weather and / or economic (loss of revenue) reasons and you can see we carried higher organic matter through into 2013. The prolonged cold spring of 2013 meant again a lot of cancelled aeration events and so we went into this summer higher in fibre than normal.

A great time to hollow core

So the bottom line is that we need to aerate more to get back on top of this and that aeration has to include organic matter removal, as well as topdressing, neither of which I know is popular in the middle of summer. For me though I think clubs have to have a look at the bigger picture because the truth is you can only paper over the cracks for so long, eventually it’ll come back to bite you in the form of grass loss to stress, higher summer and autumn disease incidence and therefore greater expenditure on fungicides. A lot of clubs are finding September a busy month now and of course in August, a lot of golfers go away on their holidays, so this month coming is really a cracking time to hollow tine, provided you are in control of plant stress, irrigation and nutrition. Assuming you are, I think you can comfortably get good recovery from 8 – 12mm hollow coring in 7-10 days, even with high amounts of topdressing. If your club doesn’t susbscribe to this viewpoint (and it’s an education process that’s required), why not do one green as an example and show how quickly the surface can be regained.

In addition, it’s very important to keep the grass plant breathing, in other words supplied with oxygen, so venting the turf using solid tines, sarrell rollers is also key leading up to and close-after stress periods, if you want to maintain a healthy grass plant.

Disease Activity

More of the same on this front as well really, plenty of high-humidity-related disease out there at the moment, so that’s Fairy Rings, Rhizoctonia, Waitea and most likely, Dollar Spot (on the continent especially). I haven’t had any reports of such, but I’d also think Fusarium will be kicking around with the arrival of moisture, however you should be able to ‘manage this out’ rather than having to spray it.

Stalky Outfield

After the dry weather of July, there’s also a much higher level than normal of stalky grass on outfield at present. It’s a blighter to cut as it tends to flatten in front of the mower. It will reduce over time as the seed stalk becomes supple, but just at the moment, it’s a pain :(

Ok, that’s all for now, enjoy the summer..

Mark Hunt

 

July 23rd

Hi All,

A late blog this week courtesy of the vagueries of French Wifi, one minute it’s here, the next it’s en vacance, like me :) I’m sitting typing this at 10 p.m., in my shirt sleeves, listening to the Nightjars churring on the hillside above me, simply magic. And because the Wifi keeps crashing, I’m finishing it with the smell of freshly-baked Croissants wafting up to my nostrils!

So the weather is breaking down a bit earlier than I predicted as thunderstorms have began to form over the U.K and Ireland on Monday and the pattern is set to continue through Tuesday, the last of the very hot days, as the temperature is due to drop down 5-6°C, as we go through the week.

The key is a change in the wind direction to westerly and that will push moist air in off the Atlantic across Ireland and the U.K throughout this week, but particularly on Tuesday when a proper rain front pushes across Ireland and the UK during the day, sparking off thunderstorms as it butts up against the humid air from the continent.

General Weather Situation

So for Tuesday we have rain pushing into south-west Munster by late morning and at the same time a band of rain / thunderstorms kicks off over the eastern / central side of the U.K. around early afternoon and this pretty much sets the scene for the day. Further west looks like staying dry, as does the east coast of Ireland, but you may just see some showers here as well. For Wednesday, the first thing you’ll notice is that it’s a little cooler, down to early / mid-twenties, rather than high twenties. That rain may still be lingering over the east coast of the U.K, but elsewhere itll be a muggy morning till the sun breaks through. By late morning, a new band of rain pushes into east Munster and heads up the very dry coast of eastern Ireland towards east Leinster, marking the first rain they’ve seen for a good while. The rain becomes more widespread as we go through the day, pushing west across central and southern England and also following the same pattern across Ireland, becoming more widespread as the day progresses.

Thursday sees a bit of a role reversal, with the rain starting off in the west of Ireland, far north of England and later into the morning / early afternoon, Scotland. As the day progresses, that rain pushes east into The Midlands, pushed along on a south / south-west wind, the key to the change in weather. Temperatures will still be holding up fair and decent, low twenties now and much more bearable at night. Friday looks a dry start for most parts, but by late morning rain pushes into the east coast of Ireland moving west as it does to affect all parts. At the same time, showers are triggered off on the west coast, principally over central / northern Wales. The area that looks like missing the vast majority of this rain is the south east, particularly Kent, which is a shame because it’s one of the driest and therefore most rain-deprived areas.

At this stage the weekend looks pretty good, temperatures in the low twenties, more cloud cover, and thick enough to give rain in south-west Munster by late morning, pushing eastwards across Ireland as it goes. The south of the U.K looks like staying dry, but rain is set fair for the north of England from late morning and there may be a chance of some light rain over the south-eastern corner of the U.K later in the morning. The wind will have shifted to the south / south-east and will be light / moderate in nature. For Sunday, we have a scattering of showers across the south-eastern part of the U.K, later in the day and a risk of more rain for Munster in the afternoon, but overall not a bad day and temperatures still on the warm side of average, but not stiffling, as of late.

 Weather Outlook

The jet-stream will have moved lower through this week, but don’t panic, it’s by no means down in the ‘bad times’ position i.e. over southern France / northern Spain, the position that gave us a wash out summer last year. That means we won’t entirely lose the heat, but it will have slipped down low enough to allow a more westerly airstream as predicted last week. This means the chance of more moisture pushing through next week is quite high and I’d pick Wednesday and Thursday as potentially the wettest days of next week, particularly for Ireland on the Wednesday. The heat will be much like the latter part of this week, low twenties / high teens, so a little down, and of course more unsettled. I’ve got a feeling it may return though for the start of August, so let’s wait and see…

Agronomic Notes

The key area of course is the effect of the prolonged heatwave that we’ve experienced over the last 2/12 weeks and in particular the requirement for irrigation.

Working on a basis of replacing 50% of E.T, we can see that we would have needed to apply just over 33mm of water by irrigation over the last 14 days or so. On a daily basis, that’s just over 2.2mm.

If you look at the last day’s data, July 21st, you can see that the E.T rate dropped to 2.6mm and that’s the effect of a lower air temperature (24°C vs. 29°C) and more cloud cover. So if the weather does pan out as expected and we lose those higher temperatures / gain more cloud cover, the E.T rate should drop accordingly (though a lot depends on the strength of the wind during that period as well).

Irrigation system coverage

A good task whilst we can still see the effects of this mini-heatwave is to go out on your golf course / sports area and assess just how well your irrigation system has been working. So photograph / detail / measure any areas of poor coverage caused by incorrect rotation sprinklers, not enough sprinklers covering a given area or poorly sited ones. Pictures tell a thousand works as they say, so nothing better to drop in front of management at a later date when you’re trying to justify expenditure on putting the job right. Normally this is not until early winter and any thoughts / memories of a heatwave are long gone, so a picture comes in very handy :)

 Disease Pressure

If the weather does pan out as expected, we can unfortunately expect an increase in disease pressure and the following are the most likely list of candidates:

  1. Anthracnose Foliar Blight
  2. Dollar Spot
  3. Fairy Rings
  4. Waitea Patch
  5. Fusarium

Anthracnose Foliar Blight is, as I understand it, the same form of the disease that causes basal rot, but it just manifests in a different way due to a different set of climatic conditions. (Kate please correct me here If I’ve got this wrong!). Research has consistently shown that a weekly input of 5kg N/Ha is as effective at treating / preventing this disease, than an application of an expensive fungicide, based on Axozystrobin or Propiconazole, for example AND it’s alot cheaper! *EDIT* Thanks to Kate Entwistle for this link about Anthracnose and its control.

So if you’re applying nutrient to greens on a fortnightly basis, you should be looking at inputting 10kg N/Hectare to keep things ticking along nicely. Don’t be fooled into thinking that the greens will bounce back from this weather on their own, because they won’t. They’ll need a little bit of nitrogen to produce amino acids, proteins and therefore the building blocks of growth and recovery.

On the subject of nutrient, I’d still be playing things cautiously until the grass is well on its way to recovering, so that’s safe forms of liquid fertiliser, light use of iron (chelated preferably) and still maximising biostimulant usage to help the recovery process on.

Make a point of checking the stressed areas once the rain arrives to look for disease, because it’s invariably here that it will first rear its head. The clean up strip is another good indicator area.

Bit of a short blog this week, my apologies, but Cafe au lait and Croissants beckons…. :)

All the best..

Mark Hunt

 

July 15th

Hi All,

Today is Saint Swithin’s day and as the saying goes, whatever weather we have now will stay for the next 40 days…

‘St. Swithin’s day if thou dost rain
For forty days it will remain
St. Swithin’s day if thou be fair
For forty days ’twill rain nae mair.’

So will Saint Swithin be correct? No I don’t think so. My feelings are that we have this weather pretty much for the next 2 weeks, with this week remaining dry and very warm. During next week I think the heat will slowly decrease (from the north first) until the end of the week when the jet stream will sink south and allow a low pressure system back into the picture for the end of July. As you know forecasting beyond 7 days is tricky, but that’s the way it looks at the moment, as usual, I’ll keep you posted although next week’s blog will be a short one because I’ll be in France on my hols.

General Weather Situation

As mentioned above, we have a pretty stable weather situation this week, with dry, warm / hot weather for most of the U.K. and Ireland, and the only variables being cloud cover and the chance of thunderstorms coming out of the heat as it builds. I won’t even begin to try to predict where these may be because a thunderstorm starts as an updraft of hot air and the catalyst for this can be any area that reflects heat, be that a car park, the roof of a building, the top of my head :), etc. so absolutely impossible to predict.

The hottest day looks like being Wednesday potentially so that’s likely to feature the highest probability of thunderstorms kicking off in the later afternoon, particularly in the south-east / south of England. Any rain this week will be confined to north-west Scotland for the early part of this week and here the cloud cover will keep temperatures confined to high teens, low twenties. There’s just a chance of some pretty localised rain in the north of England on Thursday and some parts of the south, but this will be one of those it’s raining 2 miles down the road, but not at your golf course / sports pitch scenarios, so very localised. Lastly, the night temperatures will sit in the mid-teens, so at least refeshing for those in pursuit of a good nights kip :)

The weekend looks set fair and dandy for all of the U.K. and Ireland, with Scotland warming up a little from the lower temperatures of the week so, the pattern will be early mist, cloud cover burning off around mid-morning with sunshine taking over.

Weather Outlook

It is looking like staying settled and dry through to next week, but the key will be the end of next week; around Thursday 25th July if we are going to see a change to the stable, hot, dry and high pressure scenario that we currently have. As it stands, the projections suggest that the jet stream will drop south towards the end of next week and, if this occurs, we’ll see a low pressure system push in for the end of July that will bring rain. As mentioned above, we’ll need to see the signal a lot clearer than it is now for me to be anywhere near certain that this will happen, but I’d say I’m 60% sure on it at present.

Agronomic Notes

Well I guess the main topic of conversation has to be irrigation, hand-watering and syringing. The most important aspect is balancing mains irrigation through sprinklers, with hand-watering and for sure the best approach is to apply between 50-60% of E.T loss by irrigation and then ‘top up’ on hotspots with hand-watering. Obviously there’s a huge amount of variability inherent in that statement depending on rootzone type, greens aspect (shade vs. open) and design (contouring) and this often presents a problem for understanding your irrigation requirement because no one size hat fits all.

If we look at the E.T loss since the start of the hot spell (and remember this followed what was a very dry June for some), we can see that the golf club in question has lost 36.7mm of moisture through evapotranspiration. (E.T)

So just to keep the grass healthy, we need to apply roughly 50% of this E.T loss by irrigation, that means 18mm or so. Now that’s the rough basis for irrigation requirement, your situation will undoubtedly differ, you may find you can water to replace 40% of E.T and anything above that gives too much water to the low spots on greens and so making up the rest with hand-watering is the best option.

Some people mention hand-watering and syringing in the same breath, but they are not the same. Hand-watering is to replace a moisture deficit in the soil, usually on a hotspot present on a raised surface, mound, ridge, etc, whereas syringing is applying a light spray of water straight onto the foliage of the grass with the intention of cooling the leaf tissue and slowing moisture loss to the atmosphere. Syringing is very popular in the States where temperatures are often much higher than we currently have and they stay for longer. That said, I think there is a place for syringing under the current conditions, but ultimately it’s a function of manpower and getting out between the golf, both of which can be tricky. You can argue that hand-watering also provides a syringing function as well because you are wetting the plant in the process of irrigating the rootzone in a localised fashion.

Nutrition

The same advice as last week. I’d be applying low amounts of N by foliar / liquid means using low-salt / no salt liquid feeds (so those that are very safe to use when it’s hot) and during these conditions, I’d also drop out my iron and replace with it a biostimulant in the same tankmix as the liquid feed. Make sure beforehand that it’s tankmix compatible and suitable for foliar application. (i.e you will get a benefit from it, with no nasty surprises!) If you’re applying a soil surfactant / wetter instead, I’d also be popping in a biostimulant to the tankmix, with the same concerns / considerations as above.

Disease pressure

Currently we have low amounts of disease present, but that’s not to say disease isn’t an issue because areas that showed Superficial Fairy Ring, Thatch Fungus, Fairy Rings or Take All previously, are taking a lot of work currently to stop the areas from drying out (as the first three on this list are nearly always hydrophobic in the first place). That list also includes areas affected by plant parasitic nematode damage because these often behave in pretty much the same way, due to the fact that the root system has been damaged and is therefore less efficient at taking up water. You can get to a point (especially when you have 4.0mm+ E.T days !) twhen the grass plant cannot take up enough water to keep itself alive through the damaged root system (i.e it is losing more water by E.T than it can replace) and it’s in this situation that syringing can be of great benefit by lowering E.T loss and cooling the plant tissue.

I guess if the weather does map out as suggested we’ll have had 3 weeks of hot, dry weather, following on from a dry June, so I’d suggest that disease pressure through August from Anthranose Foliar Blight may potentially be an area of concern, especially if your course / facility has a past record of this disease (so background spore levels may be high). I’ll chat about this more next week, hopefully sitting out in the French sunshine sipping a Cafe au lait :)

regards

Mark Hunt

 

July 8th

Hi All,

Phew !, what a scorcher the weekend was here in the sunny Midlands. Didn’t quite top out at the magic 30°C, but we got pretty close ! Congratulations to Scotland’s Andy Murray on his Wimbledon victory and to The British and Irish Lions as well, absolutely excellent, now all we need is for Cal Crutchlow (Coventry’s finest) to blitz Silverstone’s MotoGP at the end of August and summer will be complete in my books (from a sporting perspective of course)

As forecast last week, this week’s weather is set fair, dry and warm and no sooner than it has started, I know I’ll soon be getting questions “When is it going to rain?”. The assumption of many is that it’s been a cool, wet year up until now, but June was in fact a pretty dry month (especially compared to last year!), with rainfall varying from 27mm – Long Ashton, Bristol (Thanks James), 22mm -The Oxfordshire (Ta Sean) to 6mm, yes, that’s 6mm in the dry lands of Gravesend, Mid-Kent (Commiserations Lee). To put last year into perspective, Long Ashton recorded 188mm and The Oxfordshire,152mm, in 2012 ! Curiously I was thinking Ireland had been getting it all, as the bulk of June’s rain came from the west, but Met Éireann’s June rainfall data reveals differently, with Dublin running at 60mm (Airport), Shannon 64.2mm (Airport) and Belmullet, Co. Mayo down at 43.2mm, all low for Ireland. Even when it’s been cool, it’s been windy, so E.T rates actually ran reasonably high in June, with 76.7mm recorded at The Oxfordshire for the month. I also know we’ve already had some 4mm+ per day E.T rates for the start of July, so things are drying out big time, more of that later.

It’s that Jet Stream again….

As you can see from the schematic below showing how the weather systems played out at the back end of last week through to this week, the jet stream (the interface between the cool (blue) air and the warm (red)) has moved up north, in fact to be precise, over the last 10 days, it’s moved around 2,500 miles north, originally sitting down over The Med, till now it’s just south of Iceland ! The consequence is the warm air has pushed up and that’s what we’re experiencing now. Any sign of it moving back ?, err…no, not this week and most likely, not next week either…

General Weather Situation

This is going to be a pretty straight-forward forecast, as by and large, it’s going to dry, warm and sunny for most of the week, with precious little rain around and what’s more, a moderate north-easterly wind is going to ramp up those E.T rates during the day. A slight digression here, but on a personal note, as one who finds it very difficult to get a nights kip (too much whizzing around my head I think), at least the nights will be cool with that wind, so that should make everyone’s life easier :)

The temperature level isn’t consistent all week with things cooling down a little in the south mid-week, (though staying hot in the west and north) before ramping up again for the weekend in the south, with Saturday looking like it may compete for the hottest day of the year here. For Ireland, Scotland, and the north of England it looks like a weak weather system will come into play at the end of week, with a chance of rain pushing in Friday p.m to north-east Ireland and Scotland, moving south overnight with cloud cover into Ireland, the north of England and The Midlands for Saturday morning.  Further south, any cloud will soon burn off, with a diminishing wind, to leave a very warm day indeed for Saturday and a chance of thunderstorms by late afternoon. Sunday looks hot and humid as well but maybe a few degrees down on Saturday.

Weather Outlook

So is it really going to last ?, yes I think so, at this stage I can’t really see much sign of change (right through to the last week of July), with an Atlantic high very much in charge through next week, so dry and warm, though I suspect temperatures won’t be quite as high as this week, or this coming weekend, more low twenties, than high twenties, with a little more cloud cover, but precious little rain , except for a chance over Scotland at the end of next week / weekend.

Agronomic Notes

Insect Activity

The Welsh Chafer – Hoplia philanthus

I’ve had a number of reports of Chafer Grubs swarming over the last couple of weeks, particularly in the west London M25 / M40 area and this doesn’t bode well for the future. You guys may already know this (but I didn’t), there are 2 main species of Chafers that cause issues on turf. They are easily confused, but their life cycles are very different and that’s important when you consider control. This one here is a Welsh Chafer and it’s recorded as having a life cycle from egg to maturing adult of 2 years, though I think this may vary. (as there is evidence of a 3 year life cycle). Read about the Welsh Chafer here as opposed to the Garden Chafer here. Anyone else noticed these guys recently ?

GDD Data

Continuing the monthly updates on this subject area, you can see that June this year sits fairly well with previous years, though it has to be remembered that neither June 2012, nor June 2011 were good growth months. Cumulatively you can see we have never really recovered from that cold, early start to 2013. The monthly totals are available to download here and the cumulative totals here. Thanks to Wendy for prepping these..

 

 Coping with high E.T days….

I’ve talked about this before, but it’s worth repeating in these circumstances. Now some of you out there are using moisture meters, and by doing so, are able to monitor accurately the level of moisture across your greens, highlighting areas that need additional watering (hand watering) and areas that don’t. Not everyone is in the same fortunate position to accurately determine moisture requirements, so the next step is to replace moisture as a % of E.T loss, but again, unless you’re in possession of a good weather station, how do you know this ?, well you can buy a simple E.T vessel, which you fill up with water at the start of the day and then look at it early the next morning to determine how much water has evaporated. I work on replacing 60% of evaporated E.T loss to maintain good plant vigour, but of course there are plenty of variables that will alter this assumption, one of the main ones being turf maintained in shade. Turf in shade does not have as high an E.T loss, normally due to lack of air flow (less air flow = less evaporation), so the irrigation requirement on shady greens will normally be lower..How much lower ?, well a class I did at this years GCSAA show in San Diego suggested you should work on 50% of the irrigation requirement for a green in shade vs. one in the open. Of course this also applies to those of you maintaining pitches in stadia situations, where the balance between E.T loss, irrigation and humidity is critical. So a rough calculation, is that a hot, dry, windy day will have an E.T of 4.0 – 4.5mm, so using the 60% replacement rule, that means you should be applying 2.4 – 2.7mm of water by irrigation to keep things ticking. Irrigation on turf is at present an in-exact science and one where use of a moisture meter can help you to really understand how your greens behave irrigation-wise, budget-allowing :)

Aside from irrigation, the other general markers are to keep growth rates low with light, foliar feeds and obviously PGR’s. I’d hasten to add that this doesn’t mean that you produce a nutrient-deficient grass on the back of this because there’s at least two or three nutrient-deficient summer diseases that you’ll play right into their hands of if you do, namely Dollar Spot (1st UK report today), Anthracnose (bits doing the rounds) and Red Thread (plenty in last weeks humidity). So keeping things balanced is the name of the game during conditions like these and I’d always be maximising my biostimulant usage prior to and during this type of weather, either applied in conjunction with your foliars or with your wetting agent (I prefer the latter)

It goes without saying, but of course I’ll say it, keep cultural work to a minimum, especially in terms of lateral aeration like verticutting, scarifying and Gradening and if you do have to do them, make sure you maximise soil moisture levels in order to get recovery.

Taking about shade earlier, I noticed something this weekend, maybe a coincidence, maybe not. I sprayed 2 areas, approximately 5 weeks ago with a market-leading, tank mix (:)) of slow release, water-soluble fertiliser, liquid iron (non-staining) and a PGR. (no product names because this blog is never going to be product-based one, lol)

One area was in shade and according to a DLI meter receiving 60% of the light of the more open aspect, 2nd site. Well the area in shade is no longer under growth regulation and is actually flushing, whereas the more open aspect site is definitely still under regulation. Now it could be nothing, but a grass grown in shade is known to grow differently to one in the open, and one of the key differences is the fact that grass in shade grows up towards light and therefore has a tendency to elongate more, with more distance between the nodes. Perhaps it produces more gibberellic acid in order to achieve this ? (as GA is the hormone that promotes cell elongation), so rate for rate, needs more PGR to regulate it ?. Now you can easily produce the counter-argument that grass in shade grows less because of lower light availability limiting photosynthesis, but maybe we’re confusing growth potential with an aspect of that growth, i.e elongation, maybe it grows less, but the growth it does produce is more elongated ?. I’d be interested  if anyone has noticed a difference in the performance of PGR’s applied at the same time / rate to grass in a shady or low light situation vs. a more open site ?

I’ll leave you with that poser, time to crack on….

Mark Hunt

 

 

 

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

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