DIFFERENTIAL FUMONISIN PRODUCTION IN MAIZE HYBRIDS

Fifteen commercially available maize (Zea mays) hybrids were planted at 17 locations in 1990, and grain was analyzed for fumonisin by immunoassay. Mean fumonisin of all hybrids at the different locations varied from 0.5 to 48.5 mug/g. In general, fumonisin increased as latitude of the location decreased. Kernel characteristics such as protein, oil, starch, and total fiber of the hybrids were not correlated with fumonisin production. Over all locations, there were highly significant location and hybrid effects, and a significant hybrid X location interaction. When a subset of 11 locations, including those within the adapted range of the hybrids and excluding those with poor-quality samples or fumonisin levels outside the limits of detection, was analyzed, no hybrid X location interaction was detected and hybrid means of fumonisin ranged from 5. 8 to 30.5 mug/g. Correlation coefficients of mean fumonisin at the 11 locations with mean monthly temperature, mean monthly precipitation, and cooling degree days were not significant, except for a highly significant negative correlation between June precipitation and mean fumonisin. The range of fumonisin in commercial hybrids suggests that hybrids can be selected for areas where fumonisin is a problem.