Occurrence of mycotoxins in wheat grains exposed to fungicides on fusarium head blight control in southern Brazil

Abstract

Mycotoxins occurrence in wheat grains impose risks to human and animal health. The southern Brazil has favorable weather conditions for Fusarium graminearum infections and consequently for mycotoxins accumulation on grains. The goal of this study was to evaluate the behavior of new wheat commercial genotypes to Fusarium Head Blight (FHB), to control performance of new fungicide formulations and their relationship with mycotoxins concentration in grains. The manly mycotoxin occurrence on wheat grains in southern Brazil was deoxynivalenol (DON). Two cultivars showed high DON concentration above the tolerance limits (>3000 μg kg). Many other mycotoxins monitored presented concentrations below method detection limit. Satisfactory levels of fungicide effectiveness were achieved against F. graminearum. Some fungicides promoted a satisfactory decrease on DON accumulation in grains. The best results were obtained when prothioconazole was present. SDHI (Succinate dehydrogenase inhibitors) + QoI (Quinone outside inhibitors) fungicides showed benefic effects at FHB control at field, but it did not promote satisfactory reduction on DON contamination. Fungicides can be used satisfactory for FHB control and reduce DON contamination in grains in southern Brazil. The presence of prothioconazole should be recommended. Some genotypes showed high DON concentration and it was not directly related with FHB severity at field.

In Vitro and in Field Response of Different Fungicides against Aspergillus flavus and Fusarium Species Causing Ear Rot Disease of Maize

“…The efficacy of some molecules belonging to SDHIs against other Fusarium species has been demonstrated in China, where F. asiaticum (a member of F. graminearum species complex [47]) strains were sensitive to the novel SDHI pydiflumetofen [48]. Moreover, in Southern Brazil, SDHIs in mixture with quinone outside inhibitors fungicides (QoI) were able to reduce F. graminearum on wheat in field conditions [49].…”

Fungicides may have differential efficacies towards the main causal agents of Fusarium head blight of wheat

“…However, in the field, prothioconazole is usually applied in combination with other active ingredients to obtain a higher FHB control. In fact, the combination with tebuconazole is very frequent and it showed a high efficacy on FHB, 23,60 and in particular towards F. graminearum 61,62 …”

Integrated control of fusarium head blight and deoxynivalenol mycotoxin in wheat

“…A further, comprehensive study reported that tebuconazole + prothioconazole (TEBU+PROT; Prosaro) and metconazole (METC; Caramba) were the two most effective fungicides against FHB and DON if applied within a short period (up to 1 week) after anthesis (D'Angelo et al ., ). Under in vitro conditions, F. graminearum ascospore infection was most efficiently protected by prothioconazole (Marques et al ., ), followed by metconazole and tebuconazole (Klix et al ., ). According to Cromey et al .…”