Pydiflumetofen Co-Formulated with Prothioconazole: A Novel Fungicide for Fusarium Head Blight and Deoxynivalenol Control

Abstract

Fusarium head blight (FHB) is an important disease of small grain cereals worldwide, resulting in reduced yield and quality as well as the contamination of harvested grains with mycotoxins. The key mycotoxin of concern is deoxynivalenol (DON), which has legislative and advisory limits in numerous countries. Cereal growers have a number of control options for FHB including rotation, cultivation, and varietal resistance; however, growers are still reliant on fungicides applied at flowering as part of an IPM program. Fungicides currently available to control FHB are largely restricted to triazole chemistry. This study conducted three field experiments to compare a new co-formulation of pydiflumetofen (a succinate dehydrogenase inhibitor (SDHI) with the tradename ADEPIDYN™) and prothioconazole (a triazole) against current standard fungicides at various timings (flag leaf fully emerged, mid-head emergence, early flowering, and late flowering) for the control of FHB and DON. Overall, the co-formulation showed greater efficacy compared to either pydiflumetofen alone or current fungicide chemistry. This greater activity was demonstrated over a wide range of spray timings (flag leaf fully emerged to late flowering). The availability of an SDHI with good activity against FHB and the resulting DON contamination of harvested grain will give growers an additional tool within an IPM program that will provide a greater flexibility of spray application windows and reduce fungicide resistance selection pressure.

Effects of wheat varieties, fungicides and application time onFusariumhead blight and deoxynivalenol contamination control in wheat

“…It is significant to study the optimal application time for efficient prevention and control of FHB, and considerable reduction of DON contamination during the wheat flowering stage to ensure high‐quality, safe and efficient wheat production. Edwards (2022) reported that the fungicide was applied at three stages of wheat GS55 (mid‐head emergence), GS61 (early flowering) and GS69 (late flowering), respectively 21 . The control efficacy of GS61 on FHB incidence and DON accumulation was the highest, reaching >90% 21 .…”

“…The critical measure to control FHB is to apply pesticides at the flowering stage of wheat in a timely and appropriate manner, as the control efficacy of the same pesticide at different times of the wheat flowering stage is significantly different. 21 Previous prevention and control measures can restore 60-70% of wheat production, but DON content is still excessive. 22,23 Therefore, it is significant to establish a safety prevention and control technology based on the synergistic effect of disease control and toxin reduction in the flowering stage, to reduce toxin contamination further and ensure food security.…”

“…Once continuous rainy weather occurs, it is highly conducive to the occurrence and spread of FHB. The critical measure to control FHB is to apply pesticides at the flowering stage of wheat in a timely and appropriate manner, as the control efficacy of the same pesticide at different times of the wheat flowering stage is significantly different 21 . Previous prevention and control measures can restore 60–70% of wheat production, but DON content is still excessive 22,23 .…”

Biological potential of Bacillus subtilis BS45 to inhibit the growth of Fusarium graminearum through oxidative damage and perturbing related protein synthesis

“…Its plants may be infected by F. graminearum at all stages, and the infections cause two epidemic diseases, wheat root rot and wheat head blight, which seriously affecting the yield and quality of grain worldwide ( Stephen et al, 2015 ; Wang and Gottwald, 2017 ). To effectively kill pathogenic microorganisms in crops, the commonly used control method is to spray chemical fungicides into the fields ( Cruppe et al, 2021 ; Edwards, 2022 ), but these synthetic fungicides may remain on grain, resulting in food safety issues ( Chen and Ying, 2015 ; Rjiba-Touati et al, 2022 ). In addition, chemical agents may affect the growth of other microorganisms in the field, which can be detrimental to the structure of soil species diversity ( Bacmaga et al, 2018 ).…”

Study on Mechanisms of Resistance to SDHI Fungicide Pydiflumetofen in Fusarium fujikuroi

“…Tricarboxylic acid (TCA) cycles and electron respiration chains are the main pathways of energy metabolism. The succinate dehydrogenase (SDH) complex is composed of four protein subunits (SdhA, SdhB, SdhC, and SdhD) involved in the regulation of the respiratory chain and TCA cycle. − The flavonoid proteins SdhA and iron–sulfur SdhB are exposed to the mitochondrial matrix, while two other hydrophobic proteins (SdhC and SdhD) bind to SdhAB dimers on the mitochondrial inner membrane to anchor complex II. − SDHI fungicides specifically interfere with respiration by blocking the SDH ubiquinone (UQ) binding site formed by the highly conserved SdhB, SdhC, and SdhD residues . Recently, amino acid alterations in SdhB, SdhC, and SdhD causing resistance to SDHI have been reported. ,− The Fungicide Resistance Action Committee (FRAC) considers SDHI at medium to high risk for resistance development () .…”