|Munkvold, Gary - IA STATE UNIV, AMES, IA|
Submitted to: Corn Dry Milling Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: June 4, 1999
Publication Date: N/A
Technical Abstract: In 7 consecutive years in central Illinois, there was a high correlation between numbers of insect-damaged kernels and numbers of visibly molded kernels. Correlations between insect-damaged kernels and fumonisin levels were more variable, but generally significant when fumonisin levels did not exceed 5 ppm (5 of 7 years). Overall, fumonisin ranged from over 10 ppm to less than 0.01 ppm. State wide, fumonisin levels ranged from zero to more than 20 ppm recorded in some regions in 1998 (data courtesy of the Illinois Department of Agriculture). In some cases, insect control with adherent malathion granules or conventional sprays significantly reduced Fusarium and fumonisin levels. The most dramatic reductions (up to 30-40 fold, 1.1 vs. 0.028 and 1.4 vs. 0.049 ppm) have occurred with Bt hybrids that express the protein throughout the plant, as indicated by data from 1- to 2-acre fields in 1997 and 1998. Small plot tests run in Iowa from 1995 to 1998 with 1 to 5 Bt/nonBt pairs indicate the same utility of the Bt hybrids that express the protein throughout the plant, with reductions of up to 93% (18.9 ppm vs. 1.3 ppm). The availability of the large data set from Illinois has permitted the development of a computer program that predicts potential levels of fumonisins (and aflatoxins) using inputs such as hybrid type, insect damage, rainfall, temperature, and soil type. The program provides information to growers so they can make decisions on whether to apply insecticides/fungicides near pollination to prevent potential mycotoxin occurrence and whether to undertake early harvesting and drying in order to prevent further buildup.