The Change in Winter Wheat Response to Deoxynivalenol and Fusarium Head Blight Through Technological and Agronomic Progress

Deoxynivalenol: An Overview on Occurrence, Chemistry, Biosynthesis, Health Effects and Its Detection, Management, and Control Strategies in Food and Feed

Mycotoxins are fungi-produced secondary metabolites that can contaminate many foods eaten by humans and animals. Deoxynivalenol (DON), which is formed by Fusarium, is one of the most common occurring predominantly in cereal grains and thus poses a significant health risk. When DON is ingested, it can cause both acute and chronic toxicity. Acute signs include abdominal pain, anorexia, diarrhea, increased salivation, vomiting, and malaise. The most common effects of chronic DON exposure include changes in dietary efficacy, weight loss, and anorexia. This review provides a succinct overview of various sources, biosynthetic mechanisms, and genes governing DON production, along with its consequences on human and animal health. It also covers the effect of environmental factors on its production with potential detection, management, and control strategies.

The research progress in and perspective of potential fungicides: Succinate dehydrogenase inhibitors

Succinate dehydrogenase inhibitors (SDHIs) have become one of the fastest growing classes of new fungicides since entering the market, and have attracted increasing attention as a result of their unique structure, high activity and broad fungicidal spectrum. The mechanism of SDHIs is to inhibit the activity of succinate dehydrogenase, thereby affecting mitochondrial respiration and ultimately killing pathogenic fungi. At present, they have become popular varieties researched and developed by major pesticide companies in the world. In the review, we focused on the mechanism, the history, the representative varieties, structure-activity relationship and resistance of SDHIs. Finally, the potential directions for the development of SDHIs were discussed. It is hoped that this review can strengthen the individuals' understanding of SDHIs and provide some inspiration for the development of new fungicides.

Effect of pydiflumetofen on Gibberella ear rot and Fusarium mycotoxin accumulation in maize grain

In Ontario, Canada, Fusarium graminearum Schwabe causes Gibberella ear rot (GER) in maize, resulting in the accumulation of mycotoxins, mainly deoxynivalenol (DON), DON-3-glucoside (DON-3G) and zearalenone (ZEN) in infected kernels. Fungicides can be an important tool for managing GER and DON and other Fusarium mycotoxins in maize. Until recently, all fungicides available to growers were triazoles, thus no resistance management strategy through fungicide use was possible. In this study, a novel carboxamide fungicide active ingredient (pydiflumetofen) was evaluated against conventional triazole fungicides and mixtures for: (1) effectiveness on mycotoxins (2) optimal application timing; and (3) efficacy of application, with and without an insecticide, under natural and inoculated-misted conditions. The best timing for fungicide application was at full silk, resulting in the highest reduction of GER symptoms and lowest accumulation of F. graminearum mycotoxins in harvested grain. DON and DON-3G concentrations were reduced by at least 50% with a fungicide application at full silk. Fungicide treatments did not affect fumonisin concentrations in grain. Pydiflumetofen (94 g active ingredients (AI)/ha) and fungicides containing pydiflumetofen (75-94 g AI/ha) were similar to standard triazole fungicides (prothioconazole at 200 g AI/ha and metconazole at 90 g AI/ha) for reducing GER and F. graminearum mycotoxins under misted-inoculated plots and commercial field conditions; as a result, we expect pydiflumetofen to be competitive with triazole-only chemistries in the marketplace, which should delay the onset of fungicide resistance.

Effectiveness of a novel fungicide pydiflumetofen against Fusarium head blight and mycotoxin accumulation in winter wheat

Fusarium head blight (FHB) causes yield loss, quality reduction, and grain mycotoxin accumulations. A novel pydiflumetofen-containing fungicide, Miravis Ace, was recently registered in North America. The main objective of this study was to assess the efficacies of Miravis Ace and the timing of application alongside industry standard triazole fungicides (Prosaro, Caramba, Proline and Folicur) on suppressing FHB, reducing mycotoxins and improving wheat agronomic performance. The assessment was conducted across six natural environments on commercial farm fields and in two artificially inoculated-misted environments. All environments included 5 fungicides (Miravis Ace and the four triazole fungicides) and 3 application timings (Zadoks GS 59, 65, 69-71). Additionally, for the ZGS 65 timing, the experiment in the natural environment included a quinone outside inhibitor (QoI) fungicide pyraclostrobin (Headline). In general, Miravis Ace tended to be more effective on FHB suppression than the triazole fungicides across all environments. However, any biological differences tended to be statistically non-significant, likely because of a lack of statistical power. Miravis Ace reduced total deoxynivalenol (DON) concentration by 52-73% compared to the non-treated control. If applied at ZGS 59-65, Miravis Ace was more effective in increasing yield and test weight than the triazoles tested. Across fungicides, applications made at ZGS 65 were most effective in FHB suppression compared to earlier or later application timings. There was no evidence that pyraclostrobin increased mycotoxin concentrations. Overall, compared to the triazole fungicides, the novel pydiflumetofen-containing fungicide tended to have lower FHB suppression and mycotoxins, higher grain yield and test weight, and higher harvest moisture, but differences were not always statistically significant. Because the main active ingredient in Miravis Ace has a different mode of action than the triazoles, we speculate that this fungicide will be competitive with industry standards, and benefit strategies for fungicide resistance management.