GIBBERELLA EAR ROT DEVELOPMENT AND ZEARALENONE AND VOMITOXIN PRODUCTION AS AFFECTED BY MAIZE GENOTYPE AND Gibberella zeae STRAIN

Abstract

In 1980, six corn hybrids were inoculated with each of six strains of G. zeae in order to determine whether hybrid-strain interactions occur with respect to ear rot and mycotoxin accumulation. A statistically significant interaction was observed for mold damage, but no large-rank reversals occurred. All six strains identified the same hybrid as being the most resistant. In 1981, three of the original six hybrids were tested with three new strains. No interaction was observed. Hybrids common to the two seasons maintained their relative ranking over years. Analyses for zearalenone and vomitoxin content were performed for both years. Toxin level was significantly correlated with percent mold damage in both years (r = 0.69 to r = 0.83). When covariance adjustment for mold level was performed, hybrids were found not to differ significantly for toxin accumulation in either year. A strain and hybrid × strain effect was observed only for zearalenone in 1980. These data indicate that a single strain should be adequate for resistance screening, and confirm the importance of reducing mold levels through breeding as a solution to the mycotoxin problem.Key words: Corn, maize, Zea mays L., ear mold, mycotoxins