October FAQs 2021

October has been a mild month to date with plenty of disease pressure and as always there has been plenty of questions about which fungicide to use.

These milder periods inspired me to put this blog together looking at how the temperatures look when you break them down into hourly chunks. I put this together on the 25th October, so it's not a full months data but looking at the forecast it's only looking like we'll see more of the warmer hours and less of the cooler ones. I may well take another look at this blog once the months up to show how things compared?


Fungicide choice for October

My Fungicide of choice for most people has been FR321 and Instrata Elite through this October. As we move forward into November, some of the more northern parts of the country may well start looking towards Medallion but for now I'd stick to these two products in rotation.

We have some trials going on at STRI currently and have had the opportunity to share the data as soon as it's been reported to support our recommendation on the value of FR321 at this time.

The latest on that trial can be found here

How rainfast is FR321?

As FR321 is a fairly new solution to the industry and we've had lots of rain I guess the rainfastness question was bound to crop up. FR321 consists of 3 products, Heritage, Medallion and Ryder

  • Medallion is rainfast in 1 hour
  • But will do a good job of spore population the the lower areas of the leaf tissue / thatch
  • Heritage is rainfast in 2 hours
  • Heritage is also root uptake so would still be utilised if the plant is actively growing

We don't have any rainfastness data on the FR321 one-box solution yet so I'd stick to 1-2 hours as a minimum but the way these products work would suggest that if you were to have any wahsed off the leaf then a good amount of it would still be utilised.

I would however stick the concept of when spraying fungicides, the longer it has to dry on the leaf the better.

But I completely understand for some, a prolonged period of dry leaf is not a luxury they have!

How long will my Fungicide last?

There are lots of things that will influence the longevity of a fungicide but in simple terms the higher the pressure the shorter the amount of control you'll get. During October and particularly mild Octobers like this one 14 days of control is a realistic amount of time for a fungicide to last.

I'm not suggesting you apply every 14 days but understanding how long it will last at this time of year puts you in good position to ensure you use all the ITM tools available to you to help keep your surfaces clean.

Once your 14 days are up you decide whether the pressure is high enough to apply another one, or if using other tools can keep the pressure down enough to delay your next fungicide application.

As the temperature cools, the longevity will increase and the pressure should also reduce. If you convince yourself that you'll get 30 days control at this time of year it's highly likely you will to run into trouble. Below is a blog all about it.


Dollar spot

Yes, I'm still getting reports of Dollar spot rumbling on.


I still haven't pulled together all the weather data for the modelling for all of those people who told me they'd seen more of it.

This is a problem that is really creeping up on us as an industry and everytime I go to look at it I realise how much we have to learn about this one in the UK Climate. So watch this space and I will do some work on this one.

Acelepryn timings

Lots of questions on this one but all nicely summarised by apply somewhere between 2nd week of October and 2nd week of November.

Don't worry too much about exact dates, just get it out in that period on a day when we're seeing a good steady rainfall to wash it in, We don't want to see flooding or risk of run off just steady rain.


On the Horizon

October was the month Henry and myself through the On the Horizon Podcast reached the milestone of delivering over 2500 hours of education via this platform.

Thanks for listening.

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