Effect of husk characters on resistance to corn earworm (Lepidoptera: Noctuidae) in high-maysin maize populations

Two maize (Zea may L.) breeding populations with very high concentrations of maysin, a silk-expressed flavone glycoside. were tested for their ability to resist ear damage by the corn earworm, Helicoverpa zea Boddie. under field conditions. Tests were conducted in 2000 and 2001 at multiple locations in Georgia. The high maysin populations, EPM6 and SIM6, as well as resistant and susceptible checks. were scored for silk-may sill content. H. zea damage. and husk characters. In 2000, there was a negative correlation between husk tightness and earworm damage at three of five locations, while there was no significant correlation between damage and may sill content at any location. In 2001. EPM6 and SIM6 had approximately tell times the may sill content of the low-maysin control genotypes: nevertheless, earworm damage to EPM6 and SIM6 was either greater than or not significantly different from the low-maysin genotypes at all locations. The resistant control genotype. Zapalote Chico, had significantly less earworm damage than EPM6 and SIM6 for both wears at all locations. The results of this study highlight the importance of identifying and quantifying husk and ear traits that are essential to H. zea resistance in maize.