A bit later than usual today, my apologies, but at least I can see the rain that I predicted for today in last weeks blog actually did transpire, particularly for the south of the U.K. Read an interesting piece on contributory factors to this summer’s wet weather on the BBC Weather website (http://www.bbc.co.uk/news/science-environment-19848112) and sure enough they’re pointing at meanders in the jet stream as the reason, but the cause seems to be linked to warming of the Atlantic, less Arctic Sea Ice and for me, the low level of U.V radiation from the sun, due to the intensity (or lack of it) in the current sun cycle. Either way the trough pattern remains in place, so more of the same I’m afraid for now. Critically the last week of October and 1st week of November have for the past 4 years been unseasonably warm, so we’ll see if this pattern repeats itself.
General Weather Situation
Currently we have a band of heavy rain from The Midlands down that will be slow to clear, but the good news is we have a dry interlude before another deep depression pushes down for the end of the week, so Tuesday looks a better day for most areas, with mild temperatures and some sunshine, however a band of rain will make its way into south-west Munster and the south-west of England early doors and move slowly north to affect South Wales, Bristol and the south coast of England, pretty much up to Eastbourne. The rest of the U.K and Ireland will be dry. For Wednesday, we pretty much have a repeat as that rain fizzles out during the day, but it may be reluctant to do so from South Wales and south west Munster (Kerry).Winds will be light and southerly for most, so mild air and good for spraying. For Thursday we have a change on the way, as a cool band of air is pushed down and pressure begins to drop. This brings with it moist air and rain in a vertical line, intially for west Munster and Connacht, but this will quickly move east to affect the western side of the U.K, before moving inland to affect central areas of England and Scotland later in the day, so potentially a wet end to the day for many. Unfortunately there’s more as the saying goes with that rain intensifying over central England during Friday morning giving appreciable rainfall. West of this should be drier and brighter with only a weak band of rain pushing across Ireland during the day. That rain pushes eastwards during the day and finally clears around late evening, so we may get an inch or more in the process in some areas. The outlook for the weekend doesn’t look great for Ireland and England at least with some potentially heavy rain on the cards for Sunday, though Saturday may be ok for most areas (except south west Munster and the south west of England).
The low pressure system that is set to bring a wet end to the week is projected to intensify for the early part of next week, so strong southerly winds will push in heavy rain for many areas of the U.K. I therefore expect a wet start to next week and for most of the week, the outlook is unsettled and wet, so not great I’m afraid, particularly with the ground already saturated.
The wet weather has certainly kicked off the worm activity as mentioned last week, so if you’re able to do so, Tuesday and Wednesday offer good spraying opportunities for this application, thereafter I think it’ll be difficult to get out and apply to be honest for the next week or so.
The mild temperatures, with the odd cold night thrown in, have resulted in some heavy dews and with a moist soil, we can expect disease pressure to remain moderate to high from a Fusarium perspective. At this stage I can’t see any sign of those high teen, night temperatures we often get at this time of year, that really ramp up the disease pressure, so at least that’s some consolation.
Nutrition-wise, it depends on your perspective and how much growth you need to generate at the moment. Some people still need recovery from aeration and / or Anthracnose damage and the choice here is a high input foliar or a light rate, autumn / winter granular. If your sward is good, with nice density and health, I’d just be tickling it along at this stage with plant hardeners and elicitors, inputting around 4-5 kg / N / Hectare and balanced nicely with potassium and calcium, so any growth is hard in nature. Obviously iron plays a part in maintaining colour particularly as temperatures drop so that’s a given in my books.
It’s worth bearing in mind when you look back on this year and review your greens performance, that loss of nutrient through leaching will definitely have played a part in fertiliser efficacy and particularly longevity (and therefore greens health). This is because the summer was cooler and the rainfall events were more concentrated / extreme, and this provides ideal conditions for nutrient loss by leaching. Some work I did on leaching from USGA-spec rootzones showed that the most-readily leached nutrients were nitrogen,(both nitrate and ammoniacal), calcium, potassium and sulphur, phosphorus and magnesium, less-so. Ask yourself this question “Bearing in mind the high level of rainfall in summer 2012, did you change your nutritional input level and / or frequency to compensate? “
Another factor you should consider is the low light levels that come with unseasonably wet summers and again this really has had a pronounced effect on grass growth. Of course the tricky thing in our industry is you can’t measure it easliy because of the number of variables, but in other market sectors, like agriculture, it’s a fact that low light levels in summer 2012 have contributed to poor yields and in particular, poor quality.
I’d expect to see more moss ingression if this wet spell of weather continues, particularly on areas that may have thinned over September’s dry period (for the south). Iron is really the only recourse at this stage of the year to keep populations in check along with trying to maintain low surface moisture levels, easier said than done with the current weather though.
All the best.