Field Studies on the Relationship betweenFusarium verticillioidesand Maize (Zea maysL.): Effect of Biocontrol Agents on Fungal Infection and Toxin Content of Grains at Harvest

Maize (Zea maysL.) is a staple food for the majority of the world's population.Fusarium verticillioides(Sacc.) Nirenberg (Teleomorph:Gibberella moniliformisWineland; synonym:F. moniliformis) is both a saprophyte and a parasite of maize and can also be found as an endophyte. The presence of this fungus in maize constitutes an imminent risk due to its ability to produce fumonisins, mycotoxins with proven carcinogenic effects. The present work investigated biocontrol activity ofBacillus amyloliquefaciensandMicrobacterium oleovoransagainstF. verticillioidesinfection and fumonisin B1production in field-grown maize during four consecutive growing seasons. Treatment withB. amyloliquefaciensconsistently reducedF. verticillioidesinoculum and fumonisin content of harvested grains.F. verticillioidescount and fumonisin levels correlated negatively with rainfall regimes; however, none of these parameters showed significant correlation with yields. Treatment with these biocontrol agents may improve phytosanitary quality of the grains and reduce toxicological risk in the maize agroecosystem.