Combining ability in maize hybrid for yield-related traits and silage production

Maize cultivars developed for silage production are desirable because ensiling enables the production of high-quality feed and, increases farmers profit. Diallel cross is an efficient and advantageous mating technique that allows the selection of the best parents and crossings. The objective of this study was to estimate the general combining ability (GCA) and specific combining ability (SCA) of hybrids and their parents and to evaluate promising hybrid crosses that can be used in breeding programs. Six genotypes were crossed in a complete diallel system. Fifteen hybrid combinations, six parents, and three commercial controls were evaluated in the 2017/2018 growing season in the north and northwest regions of Rio de Janeiro state, Brazil. Nine agronomic traits were analyzed at the silage stage: plant and ear height, stem diameter, stand, husk covering, number of cobs, husked ear weight, unhusked ear weight, and fresh mass yield. The study employed a completely randomized block design with four repetitions. The parents UENF 2210, Piranão 12, and UENF 2208 presented higher GCA values for fresh matter yield and were indicated for the generation of single cross (F1) hybrids. The parental combinations of UENF 2208  Piranão 12, UENF 2208  UENF 2205, and UENF 2209  UENF 2205 had high SCA for most of the evaluated traits and were promising for the use in breeding programs. The crosses with higher average yield were UENF 2208  Piranão 12, UENF 2210  Piranão 12, and UENF 2208  UENF 2205