Fusarium verticillioides is commonly reported as the causal agent of maize pink ear rot. It produces fumonisins, compounds contaminating the kernels, toxic on animals and humans. It can infect maize kernels through silks, lesions caused by insects in the ears, and via internal, systemic infection of the corn plant. The objective of this study was to evaluate the relative importance of such pathways for maize kernel infection by F. verticillioides and fumonisin contamination. In 2007-08 in North-west Italy, in a full factorial field experiment, the effects of seed-inoculation, fungicide protection of the silks at flowering, and physical ear protection against European corn borer (ECB) were compared. The experiments were a repeated measures design with 8 replicate blocks. Fusarium species were isolated from the plants and maize seeds at different phenological stages, until grain physiological maturity. Fumonisin contamination was quantified by HPLC. The infection rate of epicotyl and crown was increased by F. verticillioides seed inoculation (+55%). Stem colonization decreased dramatically after the 2nd node, until 0-3% at the 7th node. Maize silks resulted Fusarium-free until they turn brown. The kernels were healthy during growth; infections started at the milk stage and increased during ripening. Seed inoculation and fungicide application at flowering did not show any significant effect, whereas the physical protection of the hears against ECB injuries reduced F. verticillioides infection by 49% and fumonisins by 56%. These results emphasize the epidemiological role of both F. verticillioides air borne inoculum and ECB larvae in maize Fusarium pink ear rot.
The effect of different infection pathways on fusarium maize kernel infection and fumonisin contamination
VISENTIN, IVAN;VALENTINO, Danila;VANARA, Francesca;BLANDINO, Massimo;TAMIETTI, Giacomo
2009-01-01
Abstract
Fusarium verticillioides is commonly reported as the causal agent of maize pink ear rot. It produces fumonisins, compounds contaminating the kernels, toxic on animals and humans. It can infect maize kernels through silks, lesions caused by insects in the ears, and via internal, systemic infection of the corn plant. The objective of this study was to evaluate the relative importance of such pathways for maize kernel infection by F. verticillioides and fumonisin contamination. In 2007-08 in North-west Italy, in a full factorial field experiment, the effects of seed-inoculation, fungicide protection of the silks at flowering, and physical ear protection against European corn borer (ECB) were compared. The experiments were a repeated measures design with 8 replicate blocks. Fusarium species were isolated from the plants and maize seeds at different phenological stages, until grain physiological maturity. Fumonisin contamination was quantified by HPLC. The infection rate of epicotyl and crown was increased by F. verticillioides seed inoculation (+55%). Stem colonization decreased dramatically after the 2nd node, until 0-3% at the 7th node. Maize silks resulted Fusarium-free until they turn brown. The kernels were healthy during growth; infections started at the milk stage and increased during ripening. Seed inoculation and fungicide application at flowering did not show any significant effect, whereas the physical protection of the hears against ECB injuries reduced F. verticillioides infection by 49% and fumonisins by 56%. These results emphasize the epidemiological role of both F. verticillioides air borne inoculum and ECB larvae in maize Fusarium pink ear rot.
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