Genotype (G), Environment (E) and GE Components of Crop Yields

SUMMARY Genotype-environment ( GE ) interactions as a component of historically rising crop yields are reviewed. For various cereals (both temperate and tropical), past selection has seemingly evoked responsive varieties, and GE effects constitute about one third of the total estimated yield increase due to G + E + GE . In potatoes and sugarcanes, more stable (less responsive) varieties, less dependent upon good environments to do well, have been prominent. Historically, responses have been largely due to unconscious selection, but GE effects could be deliberately manipulated by breeding if it were desirable to do so, for example, to produce varieties adapted to low-input agriculture (already an object of breeding research in a few crops).