The optimal quantity of food discarded on a farm should be close to 0 I think. Obviously things rot, but that's not the situation here. For staples it can make sense to systematically overproduce so that we dont starve when things go badly, but ideally you find some other use for the excess like we do with ethanol. But I dont think that thought process plays much of a role with nectarines.
true. but there is a difference between discarding food that has gone bad because you could not sell it, and discarding it without even trying to sell it because some exclusive contract prevents you from selling, or because you want to keep the price artificially high.