Independent consultant Dr Roma Gwynn told the Tomato Growers Association conference: "If they don't have a MAPP (ministerially approved pesticide product) number or haven't been approved by the CRD (Chemicals Regulation Directorate), they are illegal. I'm surprised growers are using them. It's an accident waiting to happen."
Properly approved biological controls "are not necessarily easy to work with", she said. "An IPM (integrated pest management) programme will have multiple modes of action. You are managing populations rather than trying to kill everything."
She continued: "It costs a lot less to bring a biopesticide forward, but it's still a lot of money. New products are coming forward in the wake of acquisitions by the big agrochemical firms. The US alone has nearly 350 biological products while the UK has 27. How do we make this market attractive for those suppliers?"
AHDB Horticulture crop-protection team leader Joe Martin pointed out that developing IPM solutions for major pests and diseases is a "strategic priority" for the levy body, alongside the development of diagnostic tests and precision management tools. "Under the Impress programme, we are looking at these problems as a whole," he said.
In tomatoes, an AHDB "gap analysis" showed the control of numerous pests and diseases needs to be addressed, including Botrytis, Verticillium wilt, powdery mildew, Pythium root rot, glasshouse whitefly, tomato russet mite, aphids and western flowers thrips.
Mutual recognition of product approvals between the UK and the Netherlands would help address these challenges, he added. But consultant and Tomato Growers Association technical committee member Derek Hargreaves said: "You aren't going to get these. I spent a long time trying to get (fungicide) Luna Privilege approved in the UK, without success. The CRD takes hazard analysis to the nth degree."