Acer macrophyllum powdery mildew

[cole morton]

Hello,

I have noticed over the past month a white fuzzy fungus develop on my acer macrophyllum leaves. I did some research and found this (https://pnwhandbooks.org/node/3069/print) which suggests the use of fungicide.
I have never used fungicide before, and was wondering if anyone had any suggestions on what would work well. Thanks!

 

[KiwiPlantGuy]

Hello,

I have noticed over the past month a white fuzzy fungus develop on my acer macrophyllum leaves. I did some research and found this (https://pnwhandbooks.org/node/3069/print) which suggests the use of fungicide.
I have never used fungicide before, and was wondering if anyone had any suggestions on what would work well. Thanks!

View attachment 163336

Hi Cole,
My 2 cents worth is -
I would be inclined to use a combination of different fungicides alternating 14 - 21 days apart. These fungicides work in the style of PROTECTANTS. Eg. They protect the leaves from infection and most don’t have an ERADICANT nature ( no kill). Next season worth investing in preventative sprays.

Unfortunately my opinion is that it is too late in your season ( Autumn ? ), for protecting the leaves as they are due to fall off soon. In other words don’t worry about it this season.

From my experience in the Nursery and Flower growing trades protecting your trees/shrubs from insects/fungi is unfortunately a ‘necessary evil’.
Of course there are many organic growers out there who can advise you in the use of Sulphur, Copper, and other naturally occurring materials to act as protectants.

Hope this helps, and I look forward to others opinions as this may be an interesting thread of the Chemical vs Organic type of grower.
Charles

 

[Yosemite Goat]

Looks like powdery mildew

 

[cole morton]

Hi Cole,
My 2 cents worth is -
I would be inclined to use a combination of different fungicides alternating 14 - 21 days apart. These fungicides work in the style of PROTECTANTS. Eg. They protect the leaves from infection and most don’t have an ERADICANT nature ( no kill). Next season worth investing in preventative sprays.

Unfortunately my opinion is that it is too late in your season ( Autumn ? ), for protecting the leaves as they are due to fall off soon. In other words don’t worry about it this season.

From my experience in the Nursery and Flower growing trades protecting your trees/shrubs from insects/fungi is unfortunately a ‘necessary evil’.
Of course there are many organic growers out there who can advise you in the use of Sulphur, Copper, and other naturally occurring materials to act as protectants.

Hope this helps, and I look forward to others opinions as this may be an interesting thread of the Chemical vs Organic type of grower.
Charles

Good to know. I will work on the preventative measures next season. I am organically inclined myself, but willing to use a chemical solution if needed. Thanks for the insight!

 

[KiwiPlantGuy]

Looks like powdery mildew

Hi Yosemite Goat,
Lol, I guess the title of the thread didn’t give enough information ( sarcasm sorry)
Charles

 

[Yosemite Goat]

I was trying to be subtle.... powdery mildew is often caused by prolonged humidity at a specific temperature.
Visit a hydroponics (marijuana) store!

 

[KiwiPlantGuy]

I was trying to be subtle.... powdery mildew is often caused by prolonged humidity at a specific temperature.
Visit a hydroponics (marijuana) store!

@Yosemite Goat -
Ok, I have taken the chill pill.

@cole morton, Sorry for hijacking your thread.
Charles.