Plum Tree disease

[RobArb]

Hey guys, me dads plum tree i think has got a disease.. Symptoms include brown/purple patches (like its wet but not) on the bark, sticky sap leaking from the tree branches, dark nobbles and a whitish/silvery leaf..

 

My first thoughts are either silverleaf or a bacterial canker, but would just thought i'd ask to see if anyone else knew what it could be and if so how best to treat it.

 

The pictures i've attached are of the leaking "sap" the others pics haven't come out well as it was going dark last night when i looked at it..!!

 

Any ideas?

[Amelanchier]

The photos you've attached are of a common defence reaction in flowering Prunus spp. called gummosis. On its own in small quantities, its a sign of good vigour. Any pics of the other symptoms????

[RobArb]

not come out unfortunately i will get some more this week in good light conditions...

 

 

The tree had a very high amount of fruit a couple years back and has since suffered with very little fruit at all... half of the foliage at the moment is of a silvery colour, i have also asked my dad to sacrifice one of the "infected branches" to check the heartwood for staining, again another symptom of silverleaf

[Arob]

Have you been feeding the tree?

(Good feeding in addition to good pruning can restore annual bearing where fruits have tended to overcrop one year then not fruit the following year.)

[janey]

Dr Janey says it looks like classic Silver leaf or Canker symtoms, like everyone else has said. Hard to say for definate with just the two piccies.

[ScottF]

I'm with Tony on the exudate. I've seen fruit trees do this one year and then seem none the worse for wear the next- even older, more senescent trees.

 

Always be wary of getting too worried about foliar disease, too. Quite often, provided the tree is otherwise healthy, it can shrug off a foliar attack. It really may be something of nothing, particularly this ealry in spring where the tree could make a second flush even if it was heaviliy defoliated. Also, early mildew attack can give leaves a silvery sheen, and I've had to advise against felling a nice fruit tree with "Silverleaf" before now as it just had a bit of mildew which a light thin helped relieve.

 

If it is silverleaf, there's very little to be done with it unless it's a very localised attack (ie you can track back a branch or a couple of branches which are affected), and cut those branches out back to the stem. Now's a good time to prune anyway as the good sap pressure will form an antibacterial layer on the wound. Please do not do what the all-knowing RHS advises and slap loads of wound paint on (yes, this is current RHS guidance).

 

Good luck!

 

S