Powdery Mildew on Courgettes

[Paulottie]

As a rule I sow curcubits sucessionally to beat this. I am on first batch-still in greenhouse-and courgettes showing powdery mildew 3-4 of 8 leaves and i'm slightly suspect about a couple of Japanese cucumbers. I planted out 1 of each variety of courgette 10 days ago at lottie but couldn't go today and check them to see. (annoying but I could reasonably discard others and replant if those are ok.) The cukes were expensive seed though. Hessayon suggests carbendazim-no longer available to me.

I dropped in at the garden centre to be told I could use Bayer's systemic 'fungus fighter' containing myclobuteril. the mix your own bottle said you could use on some fruit but I plumped for the ready mix -same ingredient (against all my anti-chemical instincts). I got this stuff home and it says 'do not use on foodcrops.'

Actually 'dropped in' belies the inconveinence -plus the expense. I'm pretty fed up- can I use this stuff? or is there something else I could try? or a green and groovy alternative?

[Paulottie]

Thank you very much LJ. and you even spelt it right...i was even looking at the bottle

[Protea]

I have looked it up in my 2007 UK Pesticide Guide - it is a systemic protectant and curative conazole fungicide.

It IS approved on some edible crops (mainly fruit) but not for cucumbers or courgettes. Although i have just found an 'off label' approval for it on protected and outdoor courgette, and protected cucumber. The harvest interval on this is 3 days. Bear in mind this is a professional product approval so the quantity of active ingredient will be different to your ready to spray bottle. Yours is likely to be much weaker in soultion.

details here: https://secure.pesticides.gov.uk/off...t.asp?pageno=2

I'm sure it will be fine.

As an alternative for the future - powdery mildew requires hot and dry conditions, so keep the plants moist, mist young plants if possible and increase ventilation. You can also try a garlic spray, or anything that is citrus based.

[Protea]

Regulations are changing all the time. My RHS book was published in 2002 so it is fairly new but just how are we supposed to keep up with the changes?

I know - its a nightmare keeping up with whats still approved!

The PSD website has databases of all registered, approved products, and SOLA database (specific off label approvals). look here: http://www.pesticides.gov.uk/psd_databases.asp but do bear in mind these are mostly professional products. There is a garden pesticides database specifically for amateur products (its on the list on that link) which is probably more use for GYO's

[Paulottie]

Thanks Protea.
Again you tell me of garlic spray. Can I make this myself?
I did spray but i cut the 2" mini cougettes off first i enjoyed them flowers and all. Then planted it out in the rain next day. The cukes did have it but not anywhere near flowering yet.
If a plant has the problem is damping down enoughto cure it or is it just a preventative measure?
No sign of Pmild on those planted at the allotment.
Will be sowing follow on batch soon.
I do have friends with spray licences but it is not really my ethos as you know.

[Protea]

Thanks Protea.
Again you tell me of garlic spray. Can I make this myself?
I did spray but i cut the 2" mini cougettes off first i enjoyed them flowers and all. Then planted it out in the rain next day. The cukes did have it but not anywhere near flowering yet.
If a plant has the problem is damping down enoughto cure it or is it just a preventative measure?
No sign of Pmild on those planted at the allotment.
Will be sowing follow on batch soon.
I do have friends with spray licences but it is not really my ethos as you know.

damping down is a preventative measure - but make sure you don't keep them wet as then you'll encourage other diseases (like downy mildew and blight - both water spread!). its never ending!!

The garlic spray you might be able to make yourself, but you can buy it off the shelf more easily. Its a garlic extract, rather than crushed garlic, if that makes sense?

The brand i know of is called New Horizon garlic barrier, google it and you should find a supplier. I've also seen it in a few garden centres.