Field application methods of biological control agents and their impact on Fusarium verticillioides count and fumonisin B1 content in maize at harvest

PEREIRA, P.; NESCI, A.; CASTILLO, C.; ETCHEVERRY, M.

Tulln, Austria

Conferencia; ISM Conference 2009. Wordlwide Mycotoxin Reduction in Food and Feed Chains.; 2009

International Society for Mycotoxicology.

The effects of four bacterial biocontrol agents on Fusarium verticillioides infection and fumonisin accumulation in maize were evaluated in a two-year study performed at field scale. Antagonistic abilities of biocontrol agents were analyzed considering two different inoculation methods, coating of kernels prior to sowing and spraying of maize ears at flowering. Kernel treatment with F. verticillioides and co-treatments with this fungus and every different biocontrol agent were also evaluated. Maize performance was assessed through determination of the number of plants per hectare, kernels yield (Kg ha-1) and kernel-cob relations. Fusarium verticillioides count and fumonisin B1 content were determined in maize grains at harvest time. Regardless of the maintenance of maize yield, kernel treatment with F. verticillioides M7075 significantly increased FB1 content during 2006-2007 and 2007-2008 maize growing seasons. Treatment with Bacillus amyloliquefaciens and Enterobacter hormaechei reduced the levels of kernel infection by the fungus and FB1 content both years of the study. Biocontrol ability of analyzed agents varied greatly depending on factors such as the method used for inoculation and the nature of the biocontrol agent. Climatic conditions, mainly rainfall patterns, also constituted an influencing factor. Results indicated that in years conducive for F. verticillioides infection and fumonisin production, kernel treatment with Bacillus amyloliquefaciens and Enterobacter hormaechei may contribute to improve maize kernel quality.