The last post of August and in my mind the summer :). As I looked out earlier this morning, it was cool and misty and more than a little autumnal, but fear not summer isn’t quite over, for this week is going to be pretty nice, with high pressure in charge across Ireland and the bulk of the U.K, with Scotland unfortunately being the exception to the rule.
The rain forecast for the Bank Holiday did indeed materialise, but it veered east overnight on Friday, so the south and east of England got more than a little drop (which I guess is good as these areas were the driest) with reports of 29mm in Surrey and 33mm in north Kent (cheers Tony, Mark). It didn’t really get any further north than The Midlands, as we got 6.5mm here.
General Weather Situation
As you can see from the animated graphic above, we have high pressure exerting its effect this week, but the north and Scotland will come under the influence of low pressure and by the end of the week / next weekend, that’ll feed cooler air south, so although it’ll stay dry, there will be some showers around and it’ll feel noticeably cooler. (Crank up the tyre warmers Cal)
So putting a little detail in here, for Tuesday we have a pretty lovely day on the cards for England and Wales at least, after the early morning mist has burnt off, with plenty of sunshine and temperatures pushing up into the low / mid-twenties I think in the south of England. Overnight a weak rain front has pushed into Scotland / Ireland and this will bring some showers through the day across both countries, but amounts should be light. Later on, this rain will push south / east affecting westerly coastlines and may give a drop over Wales in the afternoon. Winds will be light and from the north / north-east.
For Wednesday, a simlar day for the bulk of the U.K, but a better day for Ireland, with any rain clearing to give beautiful sunshine after early morning mist. That rain front will have pushed more cloud down across the U.K, so it may be more warm, muggy down to The Midlands, with the sun breaking through south of this. There’s also the chance of some localised rain across the north of England in the morning, but again, amounts should be light.
Thursday, sees a repeat of Tuesday, with a weak rain front pushing into Scotland and giving light amounts of rain during the day. This front will also push cloud across Ireland and the north of England, but it should stay dry here. Further south, after the mist has burnt off, another cracking day, temperatures in the low twenties and lovely with it. The wind direction will change on Thursday and freshen a little, after the light winds of earlier in the week, pushing round to westerly and heralding the arrival of low pressure later on.
For Friday, a band of rain is expected to push into north-west Ireland (Connacht) / Scotland in the morning and this rain will move south (/) to affect the north-west coast of England and Wales later on in the afternoon. It may just have anough moisture in it to give a light drop over The Midlands and the south-west as well.
As we move into the weekend, that wind swings round to the north-west and gathers strength, bringing a much fresher feel to the weather than of late, with temperatures sliding back to mid-high teens at best. It’ll also push in more cloud and that rain may just pop up again to affect the far south-east of England in the morning, but I think amounts will be light if it indeed does so. It’s also likely to affect western coasts of Scotland in the morning on Saturday. By the afternoon, the sun will break through over Ther Midlands / south of England and raise temperatures a little to end the day on a nice note., though it’ll still feel fresh. That fresh feel will carry on into Sunday, so bright and breezy, with that wind still fresh and from the north-west, pegging temperatures back again 🙁
It looks like next week will be a typical autumnal week, with daytime temperatures recovering from their dip at the weekend to high teens / low twenties, but that high will keep the wind direction from the north and although winds will be light, it does mean that night temperatures will stay down, possibly into single figures, so we’ll have some pretty heavy dews around next week. Looking further ahead towards the end of next week, I can see a deep low projected to sink south and that may mean cooler conditions, with stronger, north winds and possibly heavy rain.
With the rain of last week and some heavy dews following on from that, there’s been an upsurge in disease activity. When you look at the fact that the air is so humid at the moment (88% shown on the image right), this is hardly surprising. Fusarium is the main culprit with Red Thread not far behind it. Management can be tricky because normally we’re not starting to think about fungicide applications till the end of September (earlier In Ireland though) for Fusarium and using a full rate systemic now is not only costly, but also with growth levels still pushing on, getting long-term cover is unlikely. Personally I like to use a contact fungicide now, knock it back quickly and grow any scarring out.
This late summer disease activity, does highlight the issue / problem of fungicide rotation and although we are currently blessed with many fungicide product options, the plain fact is that we have very few fungicide families, between which we can rotate.
The idea behind fungicide rotation is that you alternate the chemistry of the active ingredient (A.I) that the disease is exposed to, in order to prevent resistance building up. Some chemistries build up resistance quicker than others and this is linked to the site of activity / number of sites of activity on the target pathogen. If an active is ‘single site’, like the Strobilurin family for instance, it means there is a higher risk of resistance if you carry on just using products from the same family. So to be clear, it’s not the product name in this case, it’s the family that the active ingredient belongs to. For example, if you applied Azoxystrobin and then followed that by Pyraclostrobin, you may be applying different product names, but you are not practising fungicide rotation, because both A.I’s belong to the same family – The Strobilurins. If you applied Azoxystrobin and then followed that later by applying Propiconazole, for example, the two active ingredients come from different familes (Strobilurins and Triazoles respectively) and so you are practising good chemical rotation. To date there is very little evidence in the U.K of fungicide resistance in turf, although in agriculture, it is present and in the U.S turf market, it’s a big problem on some diseases like Dollar Spot. An update on this subject area was issued by the Fungicide Resistance Action Committe and is available here – FRAC
Looking ahead, my concern would be the potential impact of legislation on this current state of affairs, for example look at the situation in Germany, they currently have one A.I available (Propiconazole as far as I’m aware ?) for the management of turfgrass diseases and so resistance is inevitiable unless more products make it to market, which is less and less likely.
So bottom line, cultural work (organic matter control) to improve the physical surface characteristics of your grass sward and thereby reduce disease activity is going to become more and more important as we go on, as will the mixture and type of grass species present, particularly when it comes to Fusarium.
As we tiptoe into September, we enter a bit of a grey area when it comes to nutrition. At the moment we have good air and soil temperatures, so the continued use of summer products is in order, however as night temperatures begin to cool off and we receive cooler rain, it’s somewhat inevitiable that the soil temperature will drop. Saying that, it was only 2012 that followed this pattern, in the previous 3 years, we actually experienced an increase in soil temperature at the back end of September (see graph)
September is a key month in my mind to get the plant hardened off before the autumn disease pressure ramps up, so you don’t want to be carrying high clipping yields / high tissue nitrogen levels into the back end of the month. For me, light rate liquids are the order of the day and you cut your cloth to suit depending on whether we get an indian summer (so the usage of summer products is extended) or a quick transition into autumn / winter. If you need to apply a granular product to get recovery from aeration for example, keep it on the lower N side, with 4-6% nitrogen in the analysis.
That’s all for now, have a good week and I’ll take this opportunity to wish Cal Crutchlow, Coventry’s finest, all the best in this coming weekend’s British MotoGP, keep it pinned mate 🙂