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Powdery mildew
Quercusrobur81
Posts: 231
Before I chop them all down, I would be really grateful if anyone can confirm this is powdery mildew:
Dont really want to lose them but I fear the worst...
Thanks
Last edited: 11 May 2017 12:46:44
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It looks like powdery mildew, particularly in the 1st pic. Does it rub off?
Powdery mildew seems particularly prevalent this year because it tolerates drier conitions than most fungal diseases. There are many spray treatments available that will help but the underlying issue is sometimes associated with lack of water. This Spring has been particularly dry (to say the least!).
If they're Cenrtaurea montana and treatment fails, I wouldn't be too concerned about cutting them down to the ground as they will grow back and flower again this year. Even if you wanted to get rid of them, they are a tough cookie due to their rhizomous roots that break off and regenerate within a few weeks.
Thanks Dave Hedgehog, yes it does rub off
.
Ah well, will give them the chop and a good water and fingers crossed they come back strong and unpowdery.
Cheers
Powdery mildew is not easy to deal with and causes farmers real grief. If you notice this on edible crops try a solution of 10% milk and water and spray the foliage. I use this on raspberries and grape vines and it knocks back the fungus in three days.
It works - but scientists are still researching WHY it works. It also deters aphids but does not treat an established aphid attack. It may be protein acids of sour milk make it hard for fungus and aphids to get a hold. Strange but true!
MLx
Oh wow-ok, might try that next time, especially if it can help deter aphids, they are all over everything in my greenhouse! Thanks for the tip ML.