Dear Mike
Because, the tree is so high it is almost impossible to spray the whole tree and you would have to repeat the exercise every two weeks, a thankless task and to be honest, bordeaux mixture will have little effect on bacterial canker. The best thing to do is to feed the tree so that it is fit and healthy to fight the disease in the first place. Diseases are a sign that it is growing in a soil which is deficient in nutrients it needs to help fight infection. If possible, get your soil tested at www.thefertileearthconsultancy.co.uk and give your tree the best conditions to grow in.
from
Alistair Olver @ The Fertile Earth Consultancy
Replied: Monday 9th of August 2010 02:08 PM