North American Fruit Explorers mailing list at ibiblio

["Alan Haigh" <alandhaigh@gmail.com>]

In the last two years I've been seeing quite a bit of "shoot blight" at a couple of sites I manage- that is fire blight that doesn't seem to start with an infection of the blossoms.  The only visible signs are blighted water sprouts, mostly in the interior of the trees.  In one site where it is apples that are infected there are a lot of cankers on big scaffolds that started from these infected water sprouts.  The trees are mostly Empire, Macoun and Northern Spy with the first two having most of the strikes.  The trees are on seedling rootstock and are about 20 years old.

 

When I asked the key Cornell commercial fruit-grower advisor about it he insisted (after a brief consultation with their pathologist) that the infections must have started on the blossoms then moved on to the water sprouts leaving no visible damage at the infections origin.  He was confident of this because there were no serious hail storms coinciding with damage and so bees must have been the vector.

 

I'm curious if others out there have seen similar infections where symptoms don't appear for about a month after pedal-fall and no damage is visible around fruiting shoots.  If so, did the blight keep coming back?  So far the damage isn't life threatening but I'm wondering where it's going.  I have so many orchards to manage so spread out that this is a very difficult disease for me to deal with.  I'm also seeking a second (third or fourth hopefully) on the diagnosis I received.