Plum Tree with green blisters on leaves

[lizzyf]

I have a Victoria Plum tree and this morning have noticed that many many leaves have like litte green blisters on the undersides predominantly around the edges. These blisters or what ever they are, are not so much on the newest leaves and many of these bumps appear to be close to the end of a vein.

Don't know if its fungal or a pest or what.

Any help would be appreciated

Lizzy

[Linnea]

Hi Lizzy

What are your current soil conditons? is is wet/waterlogged?
Could you post a piccie? as it may be easier to identify from it

Sounds a bit like oedema (although that's not usual for plums) oedmea occurs when the plant takes up more water than it can transpire which causes the cells to blister and split. much more common on vines.

[lizzyf]

Developments

What a difference a day makes as the song goes. From the leaves looking as though they had blisters on, during the course of the day the underside blisters looked more like warts and the uppersides on the leaf tuned a lighter green over those bumps. By evening those lighter grean areas on most affected leaves turned a reddy brown colour. I now suspect some sort of fly or mite or some other little devil so removed as many of the affected leaves as I could see and tried to burn them (more smoke them to death I think). Anyway I have attempted to take some piccies.

Ground wet but not too wet.

Hope I have managed to add 2 pics

Best regards

Lizzy

[rustylady]

Sounds like this http://www.kenmuir.co.uk/image/data/...ITE%20_53_.pdf

I think you've done the right thing by picking off the affected leaves.

[Nicos]

You know- your last description was exactly what I had on my pear tree back in the UK.
I never found out what it was cos we moved off the plot the same year.

Let us know how it goes

[Linnea]

pictures make all the difference. looks like leaf blister mites to me, pears very susceptible so Nicos that's what I think yours probably was. there are other species of mites that affect other trees. removing small numbers of infested leaves may affect some control but removing large amounts of leaves is likely to do more harm than good. apparently there is no noticeable affect on cropping

[lizzyf]

I am hoping to have nipped this problem in the bud (as it were). I picked off half a bucket of leaves and have hopefully destroyed them. This is on the small plum tree.

Lizzy

[Harrod Horticultural]

Hello Lizzy,
Looks to me (great pictures by the way!) like your tree has 'Plum Leaf Gall Mite'. There are a few species that cause this type of gall or similar on species of Prunus.
Its only cosmetic damage and shouldn't dramatically affect the health of the tree or its fruit yield, which is good news as currently there are no real methods of control for these mites.
You can remove the worst areas early in the summer (or at the first signs late spring) which won't prevent attack but will help with the severity of future infestations.

Good Luck
Gavin Hatt
Pest Expert
Harrod Horticultural

[lizzyf]

Thanks Gavin

Are these the things that crawl up the tree from the ground - should I paint that stuff around the trunk - not sure what it is, I half caught info about it on a gardening programme - should have been recording it.

Lizzy