1. A process for predicting the phenotypic trait of yield in a plant of a progeny maize population through analysis of genotypes of a first and second single cross hybrid maize population, said process comprising the steps of: (a) quantitatively assessing the distribution of said phenotypic trait of yield in members of said first plant population; (b) genotyping members of both populations for an inherited genetic marker; (c) evaluating said phenotypic trait in conjunction with the genotype of said first plant population to define an association between said phenotypic trait and said inherited genetic marker; (d) predicting the value of the phenotypic trait of yield in progeny of said second plant population using said association, and (e) selecting progeny of said second population based on said association.