 The variance in yield from year to year was reduced, equivalent to a yield increase of 0.8–4.2 bushels per acre.Bushel per acre yield changes were +6.4 for European corn borer resistance, +5.76 for glufosinate tolerance, −5.98 for glyphosate tolerance and −12.22 for corn rootworm resistance.The study found interactions among the genes in multi-trait hybrid strains, such that the net effect varied from the sum of the individual effects.