pear scab ?'s
I have a Harrow sweet that fruited this year for the first time.
I lost all the fruit to what I believe is pear scab. The fruit looked normal early in the season...perhaps a bit russeted by early summer and definitely undersized. Now all the fruit are cracked and corky (in appearance)on the surface.
This is the same tree that I had concerns in spring about a possible fireblight infection. I had a number of lesions on the leader and some small branches that were corky, sunken, and showed cambium stained brownish red when scratched. All effected wood got cut out.
At the time I was surprised to see it. Fireblight is pretty uncommon here in northern VT and harrow sweet is reputed to be fairly resistant (none of my other pears or apples showed symptoms)
I now read that pear scab can infect twigs, and that has me wondering if that wasn't the problem all along.
Is the pear scab limited to new twigs only? I was seeing damage to twigs as well as growth several years old.
Are the lesions present for a single season or can they become a perennial problem like a canker? Could this wood have become infected when young and maintained the scab lesion as it grew?
Is harrow sweet particularly sensitive to pear scab? Again none of the other pear varieties I have (even those on the same tree) show symptoms.
I spray the apples in spring with sulfur to control scab, but always skipped the pears. Hopefully including them in the sulfur sprays will eliminate this issue.
Any advice appreciated. I am not 100% on this being scab, No leaf damage was readily apparent nor did the fruit show the early signs of infection that I have read about and seen in a quick google search.