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Hi All,

As we head into winter, the transition is gathering pacOct2013Troughe and for the first time since early April, we’re sitting in a trough pattern this week, as the jetstream sinks further south. I see Paddy Power are giving short odds (7/2 on London, 3/1 on Dublin) for a White Christmas in 2013, maybe they know something we don’t, but I’d have to say at this stage, I don’t see this trough pattern lasting indefinitely, it’s too early yet for a set pattern to develop. Normally by now we’ve had our first run of frosts, (Mid October in 2012) , but although we’ve had the odd air frost, there’s been nothing of note, I do however think this will change looking into next week.

General Weather Situation

ParkautumnMonday for most of us has started chilly, but bright with a lovely blue sky. The few leaves left on the trees look beautiful in the park behind my house 🙂  That’s the way we’re going to stay today during the daylight hours, bright, cool, with a good, drying wind, blowing from the north-west.

Overnight into Tuesday sees a rain front pass over Ireland and then move into the south-west and Wales early doors. By daybreak that rain has left most of Ireland, just hanging around a bit on the east coast of Munster / Leinster, but for the U.K it’s well and truly entrenched over practically most of the country, except the east coast, where it won’t have reached yet. By lunchtime though, the sun is through and that rain is confined to the western and eastern coastline of the U.K, with showers over Ireland. By close of play Tuesday, the rain is almost totally cleared away, however they’ll be some persistent areas lingering across the south-west of Kerry and the U.K. Temperatures will remain cool under clearing skies, with that ever-present westerly wind, still brisk in nature.

For Wednesday, we’ll still have that persistent rain over the south-west of Ireland, England and Scotland, pushing up into Wales later in the morning. Elsewhere it’ll be dry and bright, with a brisk westerly wind keeping temperatures down to low double figures, but feeling just a little milder than of late.  During the evening that rain is projected to push eastwards across the southern half of the country, mainly affecting a line down from Nottingham., so a soggy end to Wednesday here.

For Thursday, we have more rain showers pushing in from the west, this time though mainly affecting the west coast of Ireland and the U.K, though there’s always a chance that they’ll push inland as well. Temperatures will be down a couple of degrees on Wednesday, so high single figures and typical for this time of year.  Elsewhere it’ll be bright, but cool, though again the wind will be a drying one.

Ending off the week, we carry on the unsettled theme with rain in the west of Ireland and the U.K from early doors, brighter, but cool elsewhere. Later on in the day that rain pushes eastwards and looks to get potentially heavy overnight into Saturday. Temperatures stay cool, high single figures at best, bracing in the moderate / strong westerly wind.

The weekend looks like starting off unsettled as that rain band moves across the U.K early doors on Saturday, principally affecting a line south of Nottingham again. Between the showers, it’ll be sunshine and a cool westerly wind, but through the day, the strength of the wind will drop as overnight into Saturday it swings round to the north. So Sunday looks like being quieter, possibly frosty, bright in the most part, but colder than of late, in that northerly airstream, with temperatures lucky to get above mid-high single figures 🙁

Weather Outlook

That cold, northerly airstream doesn’t last more than a day because by Monday, we’re back into a strong, westerly wind and milder with it, possibly up into the early teens again. That westerly airstream also means they’ll be sunshine and showers around, particularly for the north of England and Scotland it seems. By Wednesday we see the first autumnal high pressure system edge in from the Atlantic, so that means we’ll lose those westerlies temporarliy and the wind will drop, though I think we’ll stay north-westerly on the whole. The lack of wind will mean less likelihood of rain, but it may mean a spell of settled, dry weather, possibly with fog and frost for the southern half of the U.K at least. Further west and north, I think you’ll hang onto the westerly airstream, so the unsettled theme continues here next week and windy with it. I think that high will hang around till the latter part of the weekend, whereupon low pressure will exert itself again and we move back into unsettled weather for the middle of November.

Agronomic Notes

Since it’s the first week of the month, Wendy has kindly number crunched the GDD figures as per usual and they make some interesting reading ;

GDDmonthlycumulativeJantoOct2010to2013image

GDDmonthlycomparisonJantoOct2010to2013image

A good end, but a very poor start

The first fact we can deduce is that despite a good end to the growing season, we have never caught up from that bad spring in terms of total GDD compared to an optimum year like 2011. The second fact highlights why the growth and hence disease pressure was so high in October when you look at the GDD total for 2013 at 219, compared to 2012 at 128.5, so nearly double the growth potential this year vs. last. Interestingly you can see an alternating pattern for October, i.e. 2010 = low GDD total, 2011 = high GDD total, 2012 – low GDD total and 2013 = high GDD total. One to watch for the future maybe ?

Recovery Potential and timing of aeration

Another interesting point concerns timing of aeration and recovery potential. If you look at the total for August 2013, it’s 360.5, but by September, it’s dropped to 230.5, in other words there’s 40% less growth and hence recovery potential from aeration in September compared to August and that’s what makes August such a great month to do aeration – i.e quick recovery and therefore a faster return to a good playing surface.

This is why I like using GDD, it’s not a perfect system, but it does allow you to make an argument to say, your club, as to why aeration is better scheduled in August than September for instance. It provides some objective data, rather than just saying “August is the best month to aerate”

High GDD + High humidity = DIsease pressure

I’ve used some data kindly provided by James at Long Ashton Golf Club, (thanks James) which highlights very clearly the severity of September and October’s disease pressure periods.  Before I cover this, it’s interesting to compare data from Long Ashton with The Oxfordshire and one can see that they’re very similar ;

                                                         GDD Total Sept 2013      GDD Total Oct 2013

The Oxfordshire                                            230.5                               219.0

Long Ashton                                                  256.0                               215.0

Humidity as we know is a measurement of the amount of water vapour in the air, when it reaches 100%, the air is said to be saturated, that is it can hold no more moisture.

Humidity plays a big part in disease development, the wetter the plant leaf, the more conducive the conditions are for disease development and spread. When you look at the data from Long Ashton below, you can see that during September, there were 20 days when the humidity was > 90% and during October, 24 days, so over the 2 month period, practically 72% of the time conditions were conducive for disease development.

On top of that, there were also some clear peaks (as shown by GDD) when the grass plant (and disease population) was able to grow faster and when these co-incide with high humditiy readings, you have very high disease pressure, but also reduced longevity of fungicides. (due to more material being removed by cutting) These are highlighted by red boxes in the charts below.

GDDHumidityLASeptOct2013

 Rainfall Data

We know October 2013 was a very wet month for many, for some the wettest since June 2012, but because the main rainfall pattern was from the south west (south Atlantic low pressure systems), there’s a big difference between the south-west of the country and The Midlands for instance ;

Rainfall in October 2013 (in mm)

Launcestion                                                  257

Bristol                                                            167

Worcester                                                     147

Leicester                                                       147

Birmingham                                                 126

Thame                                                             86

Nutrition

The soil temperature is well and truly dropping away now, my gauge is showing 9.7°C, whereas a week ago, it was 4°C higher !

I don’t expect it to go back up in the near future so products applied now will last a good while longer, simply because there’s less removal in the clippings during cutting.  You can see though from the graph below how warm the soil has been during October compared to last year.SoilTempOct20132012

Nutrition-wise, I think you have a choice between granulars where they are needed (tees boxes, etc) and light rate liquids (with iron) to keep things ticking along nicely. Either way you’ll get more out of either type of fertilisation than you would have a week ago, with the lower soil temperatures and lower anticipated daily rainfall. (except Ireland, Scotland)

Spray days are very dependent on where you’re located with the south and Midlands having some good potential days through this week ?(Wed – Fri), whereas for Ireland, Scotland and Wales, life is more complicated, with possibly the end of the week for the west and none, apart from today, for Scotland (sorry lads)

That’s all for now, sorry for the late posting, you guessed it, full intray on return to work !!! 🙂

Mark Hunt