1. A multivariate mixed model method for genetic evaluation of an inbred maize plant and a hybrid maize plant, the multivariate mixed model method comprising the steps of: a) quantitatively assessing the distribution of two or more traits of interest in a population of inbred maize plants, wherein the traits of interest comprise a plurality of correlated attributes comprising grain yield and moisture content; b) constructing a relationship matrix for each inbred maize plant parent for the two or more traits of interest; c) applying the relationship matrix in a multivariate mixed model analysis for the population of inbred maize plants; d) generating field trial data for hybrid progeny of the population of inbred maize plants, wherein the field trial data for the hybrid progeny are analyzed with the multivariate mixed model analysis; and e) obtaining a predicted genetic value for said inbred maize plant, wherein the predicted genetic value includes a general combining ability (GCA) value, a specific combining ability (SCA) value, or both the GCA value and the SCA value for the population of inbred maize plants.