More fool them if that’s what they think. You only have to look around to see the increase in air borne pathogens of all sorts e.g. tree diseases, to realise that their recent virulence is more likely enhanced by recent climate patterns. The same was true of the Irish Potato Famines, and the recorded weather at that time. And I don’t think their spokesperson should be quite so patronising towards allotment holders etc either – many of whom (without chemical back-up) know more about growing potatoes than some of the farmers.
