crab apple

[clairissa]

I have a seven foot crab apple that's looking a bit sick.... there are only 3 apples on it and that's odd as normally there are loads, its covered in white cotton wool stuff which as im not sure what it is iv just tried to wash it off, I thought it may be spiders (oooh yuk)...... The bark at the bottom looks as if its ...well going and the whole plant is tatty... iv sprayed it with the usual stuff to no avail... help!!

[srodders]

Hmmm, that'll be woolly aphid. difficult to get rid of without lots af chemicals. Control it by using soapy water in the evening (washes of teh waxy subsatnce and the bugs don't like the soap. Also try to attract lots of little birds (blue tits are good) to eat up what's left. You'll never get rid of them completely, just keep on top of them.

[fran]

It sounds a bit like scale insect infestation, which I get regularly on my potted acers, and most recently on a dogwood, also in a pot. They produce lots of cotton wool like stuff, and the insects themselves are quite hard to see. They are like very flattened, legless, grey woodlice stuck on to the trunk and branches. You can scrape them off with your nails (very messy) and that takes ages. You couldn't do it on a big tree. The plant starts to look sickly and eventually kills the attacked branches. They climb up the trunk from the soil. Sorry, but I don't know of any way of removing them other than by hand.

Fran

[starloc]

It could be wooly aphid, scale insect or mealy bugs, the grey woodlouse description makes me think mealybugs, all are hard to get rid of, bayer ultimate bug killer works, but kills everything else as well, spraying with horticultural oil dilute in water or neem oil dilute in water is best, or go round the tree with a cotton bud soaked in alcohol touching them, they will die instantly,

If not wanting to kill bees with insecticide, i would go for spraying with neem oil , 1 teaspoon in a litre of water with 1 drop of dishwash liquid

[clairissa]

have to give the birds a miss, I have 6 cats. Il start with fairy liquid tonight... thanks

[clairissa]

Have washed tree in fairy Liquid solution (green of course) and it may be me but it looks better....... covered in bubbles but definitely less droopy....If it doesnt work ..well at least its clean!!!

[FB.]

Your problem is Woolly Apple Aphid (WAA).
It can be a serious pest in warm, dry years. It attacks stems and roots, but you can't to much to defend the deep roots, so the tree has to struggle on.
Normally predators will eat most of the aphids eventually, but the aphids cause knobbly wounds which can become infected with canker.

Squash or rub off the worst of the aphids on the branches if it troubles you. The only real defence is using a rootstock with WAA resistance - those prefixed with MM were bred for WAA resistance. MM106 is common. MM111 is hard to find. Other MM rootstocks are virtually impossible to find.

I'm surprised that your crab wasn't grafted onto MM106, since it's a very popular rootstock.
If you have MM106 than you might have one of the particularly nasty strains of WAA that are resistant to the rootstock defences. It is also possible that the WAA are still deterred from attacking the roots, or perhaps they have no other trees nearby, so they have to feed on your tree.

My defence is to use MM rootstocks on most of my apples, plus encourage predators. I also keep a few M prefix rootstock apples, to draw the WAA away from my others.

I posted a topic showing pictures of common apple diseases. I'm a bit disappointed that evidently not many people have taken a glance since the answer was in there.
http://www.growfruitandveg.co.uk/gra...waa_33838.html