Powder on crabapple leaves

[LucaSt]

Hi all,
I tried to look for other posts but I couldn't understand!
Can you guys have a look at this photos and tell me what that powder is?
If I pass my finger over it, some will go some will stay...can you please help me?

I also noticed that the tips of the leaves are getting yellowish!!? I think you can see that from the photos!!

Thanks in advance
LucaSt

 

[NOZZLE HEAD]

Malus are succeptable to spider mites, and powdery mildew.

From your photos I can’t tell which it is. Potassium Bicarbonate has a really good knockdown for Powdery mildew, and there are a lot of good products out there for spider mites on Malus.

 

[SeanS]

As @NOZZLE HEAD said it looks like powdery mildew. I’v been treating some roses in my garden for it. They were staying too damp and weren’t getting enough sun. Roses are very susceptible to mildew.

Looks the same as my roses did/still do. Try the bicarb suggestion and if it doesn’t work get a powdery mildew treatment.

 

[LucaSt]

Cool!

Thank you very much for your reply guys! I’ll give a go at bicarbonate and see how it goes!

 

[LucaSt]

Do you think something like this would do?

 

[SeanS]

That should work. Google “powdery mildew bicarbonate” for the way to use it, I think you just mix with water and spray/brush it on the leaves

 

[LucaSt]

Yeah I read to mix a tablespoon in a gallon of water! Thanks for the advice though!

 

[Paulpash]

Milk works too as a prophylactic

 

[LucaSt]

Good to know! Thanks!

 

[Orion_metalhead]

Are you watering the leaves when watering the tree? If so, try to just water the soil... it should help prevent in future.

 

[Forsoothe!]

You need to state where you are so others experienced in your local weather can better advise you. Mildew, and every other disease is endemic to Malus. Soap Shield is good for what ails them. Some newer varieties are more resistant and you'll get tired of spraying after a few years.

 

[LucaSt]

Hey, I thought I did, instead was in another post! Sorry, I live in the UK, in London.

 

[TomB]

Hint: when the Roseclear Ultra you've ordered arrives, look at the label.

 

[LucaSt]

Yes indeed I will!
Anyway, I was advised to use the RoseClear on the oak, but being still stressed (probably) not to use it yet, and see if it will get better, otherwise go with chemicals.

Instead for the Crabapple, being under stress as well, but infected by mildew, I was planning to use Potassium Bicarbonate that I think is less "invasive" than RoseClear ultra?!

Thanks again guys!

 

[sorce]

Welcome to Crazy!

Sorce

 

[TN_Jim]

@LucaSt, @SeanS raises a good point. Crabapple is in the rose family. Everything in the rose family seems susceptible to pathogens etc., and many hate wet leaves.

One consideration regarding anything in Roseaceae is morning sun. For example, all of my trees are on the western side of my home. While they get adequate sun, dew and any moisture will remain on the leaves much longer than ideal as the sun has to go over my home before hitting foliage. Because of this, deciduous trees more vulnerable to leaf issues I've placed much farther from the house in order to get the earliest morning light possible.

 

[LucaSt]

Cool.
I will keep them in the best position as possible where they can get better sun in the morning!

thanks Jim

 

[Forsoothe!]

If you click on your Icon on the upper right corner of the screen and fill in the location, it will help others in future discussions.

 

[Lazylightningny]

I have a problem with powdery mildew (if that is indeed what you have) in my yard, especially with crabs and maples, though mine typically hits in August and Sept. Once it's on the leaf, it's nearly impossible to get rid of. Prevention is the only way to control it, with a diligent fungicide program. The good news is, it rarely kills your tree. It can weaken it though, and leave the plant open to other diseases like leaf spot.

 

[Wires_Guy_wires]

Milk works too as a prophylactic

This is a hardcore myth in the cannabis world and it's been busted more than once. Out of the 120 cases we documented, and the 10+ years I've seen people try it, it didn't work a single time. I've tried looking for scientific research, maybe there are some sugars that mildew can't process, maybe it's the bacteria, maybe the inhibitors that milk contains, maybe the steroids, the pH.. But I've never found a single document, paper or review that mentioned anything useful if it even was described at all.

Best to get that sky cleared up before it takes hold in the bonsai world as well. It's a waste of good milk, and ants as well as multiple fungi do love the sugars that milk contains.

I'm a firm believer in household science and I'm a great fan of DIY solutions, but milk vs mildew just isn't one of them.