Influence of Messenger on Corn Yield and Mycotoxin Contamination in Mississippi

Harpin, a bacterial protein that elicits systemic acquired resistance increasing plant disease resistance in several species, is reported to enhance yield and quality of several crops including corn (Zea may L.). This experiment examined the effect of Harpin on corn yield, suppression of aflatoxin and fumonisin contamination, and Aspergillus colonization in corn grain. The experiment was conducted in 2002 and 2003 on two different soils at Stoneville, MS. Plots of a commercial corn hybrid were inoculated with Aspergillus flavus strain F3W4, formulated on autoclaved wheat (Triticum aestivum L) kernels, and applied to the soil surface at growth stages V5-V6 of the corn. Fusarium verticillioides was allowed to infect the grain naturally. Harpin was applied at a rate of 160 g/ha as a spray over the top of corn plants at growth stages V1 to V2 and again at V5 to V6. No differences in yield were observed nor did harpin have any effect on aflatoxin or fumonisin contamination. Aspergillus colonization was unaffected by harpin at one site and was lower than the untreated controls when applied at growth stages V1 to V2 at the other.