Selection efficiency in Brachiaria hybrids using a posteriori blocking

Abstract

This paper compares the efficiency of Brachiaria hybrid clone selection by either traditional analysis or aposteriori blocking, to adequately consider the effect of lower competition in the border rows of the experimental plots (bordereffect). Results demonstrated that a posteriori blocking improved selection and the reliability of the genotypic evaluation. Ofthe ten best clones, four did not coincide in the two approaches. The ranking was altered as well, which demonstrated that theindication of the five best clones, selected to proceed to pasture trials based on the traditional evaluation, was misleading.This paper confirms the usefulness of a posteriori blocking. Furthermore, the results revealed the need to impose moreeffective competition on plants in the border rows to avoid erroneous selection when conducting evaluations for agronomicperformance in Brachiaria trials.

Keywords

• competition
• forage breeding
• genetic parameters
• REML-BLUP
• repeatability.