Optimizing the number of progenies and replications in plant breeding experiments
João Luís da Silva Filho
Abstract – A determination criterion was proposed for the number of replications, r, and of evaluated progenies, Nr, given P experimental plots, with Nr=P/r, and n progenies to be selected; its application was discussed in the selection of progenies of bulk populations, derived from two homozygous parents. For a known heritability at the plot level, h20, there is a critical n below which the gain is greater with selection evaluating P/(r+1) progenies in r+1 than P/r progenies in r replications. Different h20 scenarios were simulated in the F2 and F generations, assuming no dominance. It was demonstrated that at any h20 , if n > 18.5% of P, larger gains are obtained by assuming Nr = P, showing that the augmented block design could be used in the early stages of breeding programs. The higher h20, the higher must be the selection intensity to justify the use of additional replications.