North American Fruit Explorers mailing list at ibiblio

["Lon J. Rombough" <lonrom@hevanet.com>]

That description sounds like a delayed rejection of the graft, very similar to blackline in English walnuts.  In that case, the English walnut is grafted on black walnut.  There is a cherry virus (forget which one) that can infect walnuts through the flowers.  In black walnuts, the tree reacts by immediately dropping the flowers before the virus can get into the tree.  In English walnuts, the virus just goes ahead and enters the tree.  When English is grafted on black walnut, the virus gets as far as the graft union, where the black walnut rootstock reacts by producing a layer of dead tissue to block the virus.  That causes the graft union to fail, so the top dies and the rootstock sprouts.
-Lon Rombough
Grapes, writing, consulting, my book, The Grape Grower, at http://www.bunchgrapes.com  Winner of the Garden Writers Association "Best Talent in Writing" award for 2003.
On May 30, 2005, at 7:13 AM, athagan@atlantic.net wrote:


Second in a series of woe.

Actually, it's not as bad as that.  It's been a pretty good year
fruitwise but I've run into a couple of problems that have me
stumped.  In this caee literally.

I've got a Moreland pecan that I planted three years ago.  The first
year it grew very little, establishing a good root system I suppose. 
Last year it grew more and seemed healthy enough.  I fertilized it
along with my other three pecans in early March just before bud
break.  It leafed out well in late March after the Desirable and
after that I got caught up in the vegetable garden and didn't pay
close attention.  

The next time I checked on the trees was the fifteenth of this month. 
The other three are doing well, but the top graft of the Moreland was
dead as a wedge.  There was no obvious sign of injury or disease. 
Whatever killed it worked so fast that it didn't even shed its
leaves, they're still on the dead wood right now.  There was a big
sprout coming off the roostock which is something that it hadn't done
the two previous years.  I'm not sure if the roostock sprout caused
the top graft to die or if the death of the top graft caused the
roostock to sprout out.  

Anyone have any suggestions as to what may have happened?