Help with old cantankerous apples

[Mitchell]

I would appreciate any thoughts on pruning out very decadent apples with serious anthracnose.
http://www.agf.gov.bc.ca/cropprot/tfipm/anthracnose.htm

The trees are splitting on the main trunks from old wounds cavities and rot. I suspect a hard pruning might do them in. I also do not want to cut every branch out with a canker as there would be few if any left on these trees. Can apple trees be slowly over a few years be swapped out with new branches for the old infected ones? Or will the new shoots be doomed to infection.

The owners like them and say they still produce very high quality fruit.

Thanks Scott

 

[BC WetCoast]

I'm sure you've looked at some other web sites for control recommendations as I have. But I will give you my suggestions to help others.

It also depends on how much the people are willing to spend. Recommendations would vary if it was my tree vs being hired to work on someone else's (due to time/$ limitation).

Cable/bolt the splitting portions of the trees (unsure from you description which is the most appropriate).

Do a standard crown clean and watersprout removal. Only remove the cankers where it makes sense to do so as part of the overall crown clean. That is, don't target them. I'm defining a standard crown clean as crossing branches, deadwood, branches growing toward the centre of the tree, broken branches.

I would look at removing cankers over a period of several years.

There seems to be several different strategies for spraying. The literature seems to indicate that the sprays won't eliminate the canker but will reduce its' spread. There is no registered chemical for this, however a spray Bordeaux Mix (copper oxychloride and hydrated lime) appears to slow the spread. Bordeaux is registered for use to prevent some of the leaf diseases and can be sprayed in those municipalities where there are pesticide use restrictions. Another web site talked about using copper sulphate sprays. Again, you could get away with it as the copper sulphate can also be used as a foliage spray.

If you were to use something like manzate, and the Ministry of Environment caught you, probably through a audit of your pesticide use records, you could lose your applicator licence.

My apples have these cankers. Where they are small, I cut them out. On the major limbs, I just leave them.