Mycotoxin Alert Model

Infection trials with extended leaf wetness periods of Fusarium Head Blight lead to high contents in mycotoxin. Therefore an leaf wetness period of 48 hour or more during stage 61 and 69 is assumed to give a high risk of mycotoxins. Analyses of the DON content in commercial grown wheat showed, that leaf wetness periods long enough for infection, following an initial infection in stage 61 to 69 can increase the DON values too. In case of longer leaf wetness periods mycotoxins can increase up to stage 75. Later infections will only be possible in interaction with European Corn Borer.

Fieldclimate accumulates a risk figure proportional to the infection progress for every successful infection period over the period, which has been selected to be appropriate for these calculations. A risk of 100% is given, when six completed infection periods have been fullfiled . Normally the leaf wetness period leading to a Fusarium infection is longer than in minimum needed. Therefore most Fusarium infections will lead to an risk increase of more than 17%. The risk value pointing to a problematic mycotoxin situation is depending on the field history. Corn grown after non tillage corn can only carry a small risk if it is not sprayed at the optimum situation. In not sprayed corn we have to expect increased DON values already after 35% of risk. Tillage Corn after tillage corn can carry a higher risk of 70%. First year corn should be tested for DON if the risk exceeds 100%.

Fusarium bei Mais – ein ernstzunehmendes Problem, Kolbenfusariose, Fusarium, Mais, DON, Mykotoxine, Fumonisine, Höchstwerte, Landwirtschaftliches Technologiezentrum Augustenberg (LTZ), Neßlerstr. 23-31, 76227 Karlsruhe