Yield performance of white maize (Zea mays L.) hybrids for late sowing

BIASUTTI CARLOS ALBERTO; BONGIANINO NICOLÁS FRANCISCO; DE LA TORRE MARÍA VIRGINIA; CONRERO JUAN MARCELO

Córdoba

Simposio; 2° Simposio Mejoramiento Genético; 2023

Objective: This study aimed to identify inbreeds and promising hybrids of white maize for grain yield in late sowing environments.Materials and Methods: Six white-maize inbreeds were crossed in a diallel in 2020. Lines L22, L06 and L05 (Flint type) were developed from local germplasm and lines L58 L46 and L60. (Dent type) were obtained from Cimmyt germplasm. The 15 hybrids were evaluated in 2021 and 2022 at the School Farm of de Facultad de Ciencias Agropecuarias (31° 29’ LS; 64° 00’ LO, 425 msm above sea level). The field arrangement was a randomized complete block design with two replications planted in the second week of December in each year. Common agricultural practices were followed, and the final plant density was approximately 60,000 plants ha–1. Individual and combined analyses of variance were calculated for grain yield using SAS. General and specific combining abilities (GCA and SCA, respectively), their standard errors, and the differences among them were estimated according to method 4, Model I (fixed effects). The hybrids’ sums of squares were partitioned into GCA and SCA sums of squares.Results: Poor climatic conditions were prevalent during the two years of evaluation. The combined analysis of variance showed significant year, hybrid and hybrid x year interaction effects for yield. Grain yield varied from 23.50 q/ha (L06 x L60) to 68.79 q/ha (L06 x L58). Higher mean grain yields were shown among flint x dent hybrids, in spite of no significant differences were found among hybrids groups. For the flint x dent hybrids, the highest yield was recorded for hybrid L22 x L58, which was significantly superior to all other crosses. Hybrids L58 x L46, L22 x L06, L06 x L46 and L06 x L58 were among the best producers with no significant differences among them. The highest and significant positive GCA effects were observed for lines L58 and L49, whereas L60 showed the highest negative GCA effect. The top four performing crosses having high positive and significant SCA effects were L05 x L60, L22 x L58, L22 x L30 and L05 x L46.Conclusions: Inbred lines L58, L46. L06 and L22 were identified as suitable for use in breeding programs for line and hybrid development because of good GCA effects and their performance in hybrids combinations.Acknowledgments: This research was supported by grants from Secretaría de Ciencia y Tecnología de la Universidad Nacional de Cordoba