Do certain trees bother berry plants?
The black walnut will kill blueberry plants, but will not bother blackberry or raspberry plants (the brambles). Shade can be good in hot climates (zones 5-8), but make sure it is afternoon shade for raspberries (blueberries do fine with either). As for blackberries, full sun=full sweetness. Even the slightest bit of shade seems to make them sour.