Comparison of Open-Pollinated Maize Varieties and Hybrids for Preharvest Aflatoxin Contamination in the Southern United States

Abstract

Grain from 4 currently grown adapted maize (Z. mays) hybrids and 8 open-pollinated varieties that were widely grown in the southeastern USA before 1940 was examined for naturally occurring aflatoxin [produced by Aspergillus flavus] at 8 locations in 1979 and 1980. Determinations on mature dry grain showed average aflatoxin B1 levels among the 12 entries for all locations and years ranging from 37-772 ppb. Aflatoxin levels differed significantly among entries, with the open-pollinated cv. Huffman significantly higher in aflatoxin than the other 11 entries. The mean aflatoxin level for the 4 hybrids (63 ppb) was significantly lower than the mean of 8 open-pollinated varieties (214 ppb). Insect damage rating means varied significantly among locations, entries and the interaction of entries by locations. Mean insect damage ratings were significantly correlated (P = 0.01) with aflatoxin levels but the coefficient was low (r = 0.19). When insect damage ratings and aflatoxin levels for the 12 entries were averaged over locations and years and compared by Spearman''s rank correlation coefficient, they showed a significant correlation (r = 0.53). The open-pollinated ''Huffman'' also had the highest insect damage rating. Higher temperatures in 1980 apparently coincided with higher aflatoxin levels at all locations except South Carolina.