Cherry black knot?

[DJP Arb]

Went to have a look at a job today 2 cherries and an apple to reduce and thin. One of the cherries has been pollarded at some point in the past and at every point where it's been pollarded there is the following disease / fungus.

 

Is it black knot and if so given the amount present in the canopy of the tree what's the best way to deal with it? The customer wants it thinned and reduced but what would the imitations of this be on the spread of the infection and more damage to the tree??

[agg221]

What you are showing in the picture doesn't look like a disease - it looks like adventitious roots appearing, which cherries sometimes do. They don't grow any bigger than this and are not a problem.

 

The usual problem with cherries is bacterial canker, which leaves areas of dead bark and oozing resin, plus a very thin canopy if it is near girdling the trunk. 'Shothole' in the leaves is another form. If twigs look like they have been scorched with the blossom on then you have cherry blossom wilt. Otherwise, the fairly self-descriptive silverleaf.

 

Cherries don't like being cut hard, and will generally bleed and develop canker, but they can be pruned when in growth but before August - light cuts being much better.

 

Alec

[DJP Arb]

That's just the small bit I could reach on the trunk but it has gone crazy on every previous pruning point. The customer said it didn't flower at all this year or last year

[treeseer]

What you are showing in the picture doesn't look like a disease - it looks like adventitious roots appearing, which cherries sometimes do. They don't grow any bigger than this and are not a problem.

 

Cherries don't like being cut hard, and will generally bleed and develop canker, but they can be pruned when in growth but before August - light cuts being much better.

 

Alec

 

Right; it's not clear that these growths are related to the lack of flowering.

[agg221]

That's just the small bit I could reach on the trunk but it has gone crazy on every previous pruning point. The customer said it didn't flower at all this year or last year

 

Gone crazy in what way? If it's really vigorous and calloused growth it suggests it is just responding to the pollarding. I wouldn't expect much blossom for a few years after pollarding - it kicks the tree into growth rather than fruiting mode. It will need to settle down a bit and develop a new spur system before it flowers well again.

 

Alec