Differential response of maize hybrids to field infection with Aspergillus flavus and aflatoxin accumulation in the Chaco Semi-arid region of Argentina

JAVIER MIGUEL BARONTINI; MARÍA SILVINA ALANIZ ZANON; MARCELO ALBERTO DRUETTA; AGUSTINA MARÍA RUIZ POSSE ; ADA KARINA TORRICO; MARÍA DEL PILAR MONGE; RAÚL ESTEBAN CANDELA; SOFÍA NOEMÍ CHULZE; MARÍA DE LA PAZ GIM´ENEZ PECCI

CROP PROTECTION

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2022

0261-2194

Maize is affected by Aspergillus flavus and by the contamination of its kernels with aflatoxins, of which AFB1 is themost important. The Chaco Semi-arid is a region of Argentina in which the climate conditions increase thisproblem and due to the use of resistant cultivars is the best available tactic to reduce aflatoxin accumulation, weanalyzed six hybrids against artificial inoculation with native aflatoxin-producing isolates of A. flavus. Amultifactorial experiment was conducted in three complete randomized blocks, under Inoculated and Non-Inoculated treatment, in two locations and during two growing seasons, in which yield, kernel infection, andAFB1 accumulation (using HPLC) were evaluated. P2089VYHR was outstanding during 2018/19 with 11,089 kgha􀀀 1, coinciding with the growing season with the highest rainfall and 4% decrease in yield (395 kg ha􀀀 1) wasobserved between treatments. No yield differences were observed in the hybrids between localities, or in thehybrid × treatment interaction. The level of infection by A. flavus showed differences between localities andgrowing seasons but not between hybrids. The Inoculated treatment registered kernel infections above 50%,while natural infection was 35% during 2019/20, associated with rainfall below crop requirements during theflowering period. The AFB1 accumulation analysis identified P2089VYHR and P1366VYHR without AFB1accumulation. Yield correlated negatively with the percentage of kernel infection, but not with AFB1 accumulation,while a positive correlation was observed between these last two parameters. The pathogen causes adecrease in yield in the region and there are hybrids that are resistant to AFB1.