An integrated approach to the evaluation of the efficacy of fungicides against Fusarium culmorum, the cause of head blight of wheat

All the registered Strobilurin-containing chemicals and one Azole known for its higher efficacy to control the pathogen were compared in a fungicide trial in 2001 on wheat inoculated with Fusarium culmorum. Two application times (BBCH 39 and BBCH 51) were used for the Strobilurin fungicides, whereas the Azole was applied at BBCH 65. Visual disease assessment, enzyme-linked immunosorbent assay (ELISA), a mycotoxin test, 1000-grain weight and yield assessment were used for evaluation, and all the techniques in different ways revealed differences in the efficacy of the chemicals. Whereas visual disease assessment showed the effect of the chemicals on symptom development, ELISA and the mycotoxin test indicated differences in the treatments on grain contamination by the pathogen and its mycotoxin, respectively. Assessment on 1000-grain weight and yield also showed the impact of the treatments in reducing the effect of the pathogen on grain production. Correlation coefficients calculated for the different parameters were significantly higher, indicating that a strong relationship existed among the various parameters used for evaluation. It was thus assumed that any of the techniques can be used to make general recommendations about the effect of chemicals on plant pathogenic fungi such as F. culmorum.