Adaptability and stability of maize cultivars for silage in relation to the rumen degradable dry matter yield

A study was conducted in five locations to evaluate the silage potential of eight maize cultivars estimated by the rumen degradable dry matter yield (kg/ha). A significant interaction of genotype x environment was found for this characteristic, indicating a differential behavior of the varieties when environmental conditions changed. Although the variety BR HT2X had a high dry matter yield, it was the one which contributed most to the genotype x environment interaction. Nevertheless, it presented unpredictable behavior, thus it is recommended for situations of high levels of technology when effects of unfavorable conditions are minimized. The varieties BR 205 and AGM 2010 outyielded the others and are recommended as materials of wide adaptability and high predictability. The varieties BR CMS 473 and mainly BR 106 presented lower yields. However, they exhibited a predictable behavior, indicating invariant response to environmental improvement which characterizes rusticity.