Additive Genetic Variance
2 always outperforms Variety 1 over the complete
range of environmental conditions (e.g., nutrient-poor soil at
EQ index = 40, or with added fertilizer at EQ = 90). The relative
response is predictable from experiments in any environment. Variety 2 may be
described as "genetically
superior" to Variety 1.
Note however that there is
considerable scatter about the means, and that Variety 1 in a good environment
outperforms Variety 2 in a poor environment, if
the difference in EQ is 30 points or more.
Figure ©2002 by Griffiths et al.; all text material ©2014 by
Steven M. Carr