Avaliação dos parâmetros genéticos em progênies de meio-irmãos de uma sub-população de milho composto Flint para resistência à lagarta-da-espiga Helicoverpa zea (Bod.)

One hundred of half-sib families of a subpopulation of maize (Zea mays L.)Flint Composite were evaluated in the field, to verify the genotype resistance to the corn earworm Helicoverpa zea (Bod.). For this subpopulation, the obtained value of corn earworm damage mean was 1.14 cm of length in the ear determined by the Widstrom scale and the experimental variance coefficient (CVE) was 23.4 %. Of the evaluated genetic parameters the estimates of heritability was 6%, genetic variance was 0,0015 cm2 and phenotypic variance was 0.025 cm2 for H. zea damage. However the length of the husk top and husk compactation the obtained values of the heritability was 75% and 72% respectively. Therefore, this subpopulation of the maize present genetic variability sufficient for utility in the breeding programs, though the resistance to the corn earworm can be increased, through the breeding of morphologic characters directly related to the insect, such as the husk compactation and length.