title: Dynamics of mycotoxin and Aspergillus flavus levels in aging Bt and non-Bt corn residues under Mississippi no-till conditions.
abstract: Mycotoxin and Aspergillus flavus levels in soil-surface corn debris left by no-till agriculture methods (stover, cobs, and cobs with grain) were determined during the December-March fallow period for near-isogenic Bt and non-Bt hybrid corn. By December, average mycotoxin levels in non-Bt corn were many times higher in cobs with grain than in grain harvested in September (total aflatoxins, 774 vs 211 ng/g; total fumonisins, 216 vs 3.5 microg/g; cyclopiazonic acid, 4102 vs 72.2 microg/g; zearalenone, 0.2 vs < 0.1 microg/g). No trichothecenes were detected. Levels of mycotoxins and A. flavus propagules were approximately 10- to 50-fold lower in cobs without grain and stover, respectively, for all mycotoxins except zearalenone. Mycotoxin levels in corn debris fractions decreased during winter but began to rise in March. Levels of all mycotoxins and A. flavus propagules were lower in harvested grain and debris from Bt than non-Bt corn, but differences were significant (p < 0.05) only for aflatoxins.
authors.affiliation: USDA-ARS, Crop Genetics and Production Research Unit, Stoneville, Mississippi 38776, USA. Hamed.Abbas@ars.usda.gov
authors.forename: Hamed K
authors.initials: HK
authors.lastname: Abbas
authors.forename: Cesare
authors.initials: C
authors.lastname: Accinelli
authors.forename: Robert M
authors.initials: RM
authors.lastname: Zablotowicz
authors.forename: Craig A
authors.initials: CA
authors.lastname: Abel
authors.forename: H Arnold
authors.initials: HA
authors.lastname: Bruns
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Dong
authors.forename: W Thomas
authors.initials: WT
authors.lastname: Shier
mesh_terms: D000348:Aflatoxins / Q000032:analysis; D000383:Agriculture / Q000379:methods*; D001231:Aspergillus flavus; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics; D004731:Endotoxins / Q000235:genetics; D037341:Fumonisins / Q000032:analysis; D015870:Gene Expression; D006460:Hemolysin Proteins / Q000235:genetics; D008922:Mississippi; D009183:Mycotoxins / Q000032:analysis*; D030821:Plants, Genetically Modified / Q000737:chemistry / Q000382:microbiology*; D012621:Seasons; D012639:Seeds / Q000737:chemistry / Q000382:microbiology; D013997:Time Factors; D003313:Zea mays / Q000737:chemistry / Q000235:genetics / Q000382:microbiology*
chemical_list: D000348:Aflatoxins; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D037341:Fumonisins; D006460:Hemolysin Proteins; D009183:Mycotoxins; C030956:insecticidal crystal protein, Bacillus Thuringiensis