For varieties that are often listed as requiring cross-pollination, wouldn't it be more accurate to say "cross-pollination required to produce higher yields"? What sort of yield can be expected for a tree that isn't cross-pollinated? Yield will of course depend on the variety but in what magnitude? (e.g. a dozen vs. dozens?) For the non-commercial grower, would this lower yield still be enough to satisify the average grower and with the added benefit of fruits containing fewer seeds?