A grower brought up the fact that mercury levels in any fish fertilizer might be of concern. I'm a big proponent of unpasteurized liquid fish as part of the "four holistic sprays of spring" that I've been recommending as a means of supporting beneficial biology through the primary infection period. The fatty oils in a good fish product are fungal food extraordinaire. Does anyone have anything specific to make a case that mercury levels should indeed negate the use of fish in the orchard?