Identifying inbred lines capable of improving ear and stover yield and quality of superior silage maize hybrids

Maize (Zea mays L.) is an excellent feed, whether fresh, chopped, or ensiled. Silage maize hybrids have been developed for temperate-cold regions of Europe and North America, but limited research has been done to develop silage hybrids for temperate and warm-temperate regions. This study was conducted to identify inbred lines that could be used to enhance the stover and ear fractions of existing hybrids for warm-temperate areas. Forty-five single-cross hybrids were developed from 10 inbred lines and evaluated in six environments. Ten inbred lines were evaluated for potential to improve the best hybrids by Dudley's and Metz's methodologies. Hybrids differed significantly (P < 0.01) for ear (EY), stover (SY), and whole-plant dry matter yield (WY), in vitro digestibility of whole-plant dry matter (iDW), and whole-plant digestible dry matter yield (WDY), differences among hybrids were not significant for in vitro digestibility of ear (iDE) and stover (iDS). Four outstanding hybrids were selected as target hybrids for improvement on the basis of YSi (Kang's Yield-Stability Statistic) of mean WDY and their stability across environments. Inbred lines that were able to increase SY were not the same ones that would increase EY. Inbred PR4 had outstanding potential to improve the SY of any hybrid. Inbred B84 had greatest potential to enhance EY. Inbred lines showed differential capacity to generate improvement according to the fractions that were evaluated. Finally, inbred lines from the North American Corn Belt did not demonstrate potential for enhancing SY when they were compared with local flint inbred lines.