With new single site chemistry en route to market, the industry needs to be mindful of product stewardship, Jonathan Blake told the BCPC Review audience.
He said: “Looking at SDHI mutants, what is noticeable is that if you increase dose, you find a higher level of more insensitive mutations.
“There is a clear message that the more we apply in a higher dose, the more we are selecting for insensitivity.”
It is a similar pattern with the number of applications, he said. Studies found when an SDHI fungicide was not applied, mutation frequency was around 40 per cent.
When one SDHI was applied at a 75 per cent dose, there was a 10 per cent increase in mutation frequency, and after two applications it rose to around 60 per cent frequency.
“Clearly the frequency in which we apply also accelerates the development of insensitivity,” Mr Blake said.
“The more we can just use these chemistries where we need them, the longer we will have them for use.”