Resistensundersøgelser i meldug
Konklusion
Meldug opsamlet fra 9 lokaliteter i 2022 er testet for forekomst af strobilurinresistens. Meldug fra en dansk og tre svenske lokaliteter viser tegn på strobilurinresistens i væksthusforsøg. Disse resultater og tidligere undersøgelser (Heick et al. 2019) viser at strobilurin resistens i bedemeldug findes i Danmark og Sverige. Indtil videre er der ikke set en nedsat effekt af strobiluriner i marken pga. resistens. Til bekæmpelse af meldug anbefales det at blande flere virkemekanismer for dermed at forsinke spredning af resistens.
Conclusion
Powdery mildew samples from Denmark and Sweden were tested for strobilurin resistance in 2022. One samples from Denmark and three samples from Sweden were tested positive for strobilurin resistance in a greenhouse test. These results and previous studies (Heick et al. 2019) show that strobilurin resistance in powdery mildew is found in Denmark and Sweden. So far, no reduced effect of strobilurins has been seen in the field due to resistance. To control powdery mildew, it is recommended to mix several modes of actions of fungicides in order to delay the spread of resistance.