Diseased Quince (and apple)

michael.br.thorne

Hi all, 

I’ve recently moved into a house with 2 mature trees, a quince and an apple. They are pretty close together such that their branches will mingle when breezy. Last year we got HUGE harvests of each but the quince in particular were not in a good state - they had lots of spots and ultimately we only ate probably about 20% (which was still 100+!). This year the quince tree has one quince and it’s leaves are getting brown spots, these then spread until the leaf is crispy then they drop off. The fresh shoots are green and unaffected. Some branches (particularly thinner ones) when cut have a black to grey colour running through them. I am going for a seriously hard prune ... can anyone make any other suggestions or knows what this is? It is now spreading onto the apple tree too! 

My descriptions are poor poor so I’m posting plenty of pictures. 



Fresh leaves are essentially free of the disease except a little misshapen. 



An an example of a typical leaf on the tree today. 




Most extreme case case of black in the branch



Underside of leaf



Another typical leaf 



Extent of tree after first part of hard prune. Apple tree in the back 



Effect on a fully pruned branch - total disaster basically!! 




Please help!!!

BobTheGardener

I think it is suffering from a number of problems, including drought and bacterial leaf spot.  The most worrying though is the staining of the heartwood in your 4th photo which could indicate verticillium wilt, which is soil-borne and fatal.  If you are seeing similar staining on other cuts, I would get a tree surgeon in to diagnose.

michael.br.thorne

Evening. Thanks very much for responding and giving your time - really appreciated. 

There aren't any other cuts as severe as that one but there are other branches with a slight black
hue running through. I’ve tried to ensure when pruning I go further down than these but I’ll be honest parts are looking a bit stumpy!! I’ve hard pruned one side to get it away from the apple tree as I am confident the problem is spreading. 

Is there anything I can do for bacterial leaf spot? Obviously with the drought I can water it 😂🤣 is it that simple? 

michael.br.thorne

This sort of sight is more common re: branches and possible verticillium wilt - again it’s not universal though 

BobTheGardener

There is enough staining there to warrant proper tests, I would say.  As far as the leaf spot goes, a healthy tree will normally just shrug-off an infection and grow new leaves but weakened trees will see more severe damage like this.  I think all you can do (assuming it isn't VW) is cut-out any badly affected growth, water it really well, feed it & cross your fingers.  Ideally, all trees should have a circle of soil, free of grass and other plants, at least  a metre diameter around the base of the trunk;  Grass always out-competes fruit trees and bushes.  If you mulch that cleared area with well-rotted manure once a year in autumn, the tree will get all of the nutrients it needs.  Unfortunately, there aren't really any treatments available for leaf-spot (or verticillium wilt for that matter.)

Good luck with any attempted rescue plan - trees in this family can go on for decades, even with fatal infections.