Submitted to: Plant Health Progress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 15, 2005
Publication Date: July 20, 2006
Citation: Abbas, H.K., Bruns, H.A., Abel, C.A. 2006. Influence of Messenger on Corn and Mycotoxins in Mississippi. Plant Health Progress. doi:10.1094/PHP-2006-1016-03-RS. Interpretive Summary: Corn in the midsouthern USA is often infected by fungi (molds) that produce toxic compounds called aflatoxin and fumonisin that contaminate corn. This leads to economic losses for corn farmers. Harpin, a bacterial protein, is reported to increase yield in certain crops and improve their resistance to plant diseases. We evaluate harpin on corn to see if it would protect against ear rots caused by the fungi Aspergillus and Fusarium which produce the cancer-causing toxins aflatoxin and fumonisin. We found that harpin has no effect on aflatoxin or fumonisin contamination or on the growth of the fungi that produce them. Therefore, harpin is not a cost-effective treatment for this condition, and this information will save farmers the expense and time of using this compound.
Technical Abstract: Harpin, a bacterial protein that elicits systemic acquired resistance in plants, can be isolated from Erwinia amylovora and Pseudomonas syringae. It is reported to enhance yield and quality of crops such as corn (Zea may L.), rice(Oryza sativa L.), cotton (Gossypium hirsutum L.), tomatoes(Lycopersicon esculentum Mill.), and strawberry(Fragaria virginiana Duchesne). Harpin is also reported to increase plant disease resistance. We evaluated Harpin to determine if it would protect corn against Aspergillus and Fusarium ear rots and decrease the accumulation of aflatoxins and fumonisins. The experiment was conducted in 2002 and 2003 at two locations in Stoneville, Mississippi. Plants were inoculated with A. flavus, strain F3W4, formulated on autoclaved wheat (Triticum aestivum L)kernels and applied to the soil surface of corn at growth stages V5 – V6. Fusarium verticillioides infected the corn naturally. Messenger at a rate of 2.25 OZ/A was sprayed over the top of corn plants at growth stages V1 – V2 and again at V5 – V6. Six treatments were used for the application of Messenger. No differences in yield were noted. Harpin had no effect on aflatoxin or fumonisin contamination or their respective fungi.