On fumonisin incidence in monoculture maize under no-till, conventional tillage and two nitrogen fertilization levels

BACKGROUND: Fusarium ear rot and fumonisin contamination are serious problems for maize growers. The lack of maize genotypes highly resistant to fumonisin contamination emphasises the need for management strategies to prevent contamination by this mycotoxin. There are conflicting reports regarding no-till and nitrogen (N) fertilisation practices in relation to the incidence of fumonisins. In this study the effect of no-till compared with conventional tillage and of N fertilisation rates on fumonisin occurrence was investigated over three years in Northern Italy. RESULTS: The average contamination of grain by fumonisins B1 and B2 over the three years was significantly different, with a lower value in 2000 (516 μg kg−1) than in the other years (5846 and 3269 μg kg−1 in 2001 and 2002 respectively). Conventional tillage and no-till treatments had no significant effect on the incidence of fumonisins. This finding suggests that above-ground residues infected by Fusarium would not lead to an increase in fumonisin incidence. However, N fertilisation significantly increased fumonisin levels, by 99 and 70% in 2000 and 2001 respectively. CONCLUSION: Maize monoculture does not show a cumulative effect on the occurrence of fumonisins, while high rates of N fertiliser consistently result in elevated fumonisin levels. Both these effects can be influenced by annual meteorological fluctuations.