May FAQs 2021

Should I apply a fungicide or let it grow out?

It's been so cold and wet this May! I guess it makes a change from the cold and dry that April threw at us! What that has led too is an unexpected amount of Fusarium, or at least Fusarium that just won't go away. I got asked regularly at the beginning of the month the old question Fungicide or grow it out? My answer to this question generally falls like this:

  • Spring - let it grow out - we have good growing conditions ahead
  • Autumn - Fungicide - we don't have good growing conditions ahead

But this is no ordinary Spring! I put a blog together about the challenges May has thrown at us here...... If I'd known what May was going to be like I think I'd have offered a different answer and advised the use of FR321 which is a one box solution for weather conditions like this.

Read the blog for more, but for my area of the country the May temperature was closer to November than October and the agronomic odds of it being that cold are 18:1. So my advice is based on the odds - but I guess we all wish we could put our money on a horse after the race is run!

When should I next apply my PrimoMaxxII?

With May being so cold it is an obvious question, turf isn't growing - is that a PGR response or mother nature putting on the handbrake? I put a blog together about it here.... but the short version is simple stick to the below:

  • Cool but just growing: Apply every 4 weeks
  • In between: Apply every 3 weeks
  • Peak summer: Apply every 2 weeks
  • and remember, adjusting the rate will alter the levels of suppression not the period it lasts.


It's been a hectic month for LeatherJackets and I see many of you have been sheeting on a regular basis to help you deal with this challenge. I'm sure you'll all be aware that BIGGA put together a webinar and asked me to get involved. That has led to a whole host of questions that are BIGGA are putting together as a document as I write. But I promise I will share all the answers on here when I get time to put them together.

I have seen a different species of cranefly laying in greens this year - a Spotted Cranefly and to my mind it throws open the question - How do we know we only get 2 species of cranefly laying in our greens? There's hundreds of different types, do only 2 species lay their eggs there? Read my thoughts here.....

I've also been surprised this month at the lack of a peak in the hatch pattern, I suspect again that's temperature related but we'll only know if people add there data to PestTracker read my thoughts on temperatures and Spring hatch here....

Hopefully we are at the end of this difficult journey for 2021 and to help us understand it better we really need to log where we are now - I talk about how you can gather this data in this blog....

This May has been a particularly bad one for this challenge and I suspect it's simply because its been so cold and growth just hasn't taken off this year. These really cold Springs are exactly when we'd like to reach for the "curative" type products that we used to have but no longer have access too. I really believe and stand by all the registration process and believe it's all for the right reason but I really struggle knowing how much anxiety these cold Springs, high leatherjacket pressure and lack of control tools on the shelf causes Course Managers.

Dry April lack of growth, thin bunker banks and a big event that could get some TV coverage – will Ryder help?

Yes, absolutely but theres a few caveats

  • Don’t get it in the sand, whilst it will stain the sand a bit of blue pigment will easily rake out and can be redistributed easily it’s not a job we want to create for ourselves.
  • Don’t go too high a rate – In all the work we’ve done, we’ve never seen a benefit of going higher that 2 litres / Ha. It’s not something we’d recommend either so if you want to max out your Ryder application – 2L/Ha is your top end, don’t waste your time on a higher rate.
  • Add some Qualibra – in fact we’ve found simply adding some qualibra to the ryder will increase the intensity of the colour greater than increasing the rate and you’ll get the added benefit of a great wetting agent on your bunker banks.

Can you help me with rates of Primo Maxx II on bunker banks?

3.2L/Ha is the highest rate you are permitted to apply Primo Maxx II at and that may give you a little yellowing, which is nothing to worry about abut something you should be aware of. That can be easily negated by using a small amount of Nitrogen (2Kg N/ha) or Ryder depending on what you’re trying to achieve. Generally on bunker banks it’s simply a case you slowing growth to reduce labour inputs. If you can tolerate the yellowing then just use the Primo, if you want green banks then look to Nitrogen or Ryder – Nitrogen will encourage the sward to thicken as the additional energy will be invested in growth but Ryder will not encourage any extra growth and help to maintain colour.

Before you choose your combination it’s worth thinking about your objective.

From an application point of view, If you can achieve 300l/ha of water in your knapsack then I would go with that, but from experience 250L/ha of water is more achievable.


Henry from ICL and myself are now putting together a monthly Podcast covering these types of things and rather than looking back (like I do here), it's our chance to look forward.

Have a listen and let us know what you think in this feedback form...... all feedback helps us shape how this sounds in the future.

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