Granny May Need Sunscreen

What the heck is going on with the Granny Smith tree?!  The little darling has only been in the garden since 2009.  As a bare root, it was planted as directed with fertile, well draining soil.  The young, flexible stems were patiently and gently bent to form the desired espalier form.  Granny is dormant sprayed each winter with at least 2 or 3 applications of cooper and pyrethrum.  The bed is kept clean.  She’s fed regularly.  Fruit was produced in both 2009 and 2010.  So what gives?

The problem is at the lowest lateral and at the graft joint.  The bark is split and there are signs of insect “leavin’s”.  This could be the result of sun scald.  The effected area is on the south side of the tree.  If this is a result of sun damage, I wonder if painting the trunk helps or should I consider shading these trees.  Being that they are espalier, they are wide open to the sun.  Sun scald may explain damage to the peach and nectarine trees as well.

Note:  All trees in the garden had a 3rd application of pyrethrum (no copper) except for the Santa Rosa Plum because it is blooming.  The Blenheim Apricot buds broke late this afternoon.