Biological alternatives to chemical pesticides

With increasing consumer pressure on both farmers and supermarkets to minimise the use of chemical pesticides in fruit and vegetables, a new study, funded by the Economic and Social Research Council (ESRC), looks at why there is currently little use of biological alternatives in the UK.

Biological products, known as biopesticides, can play a significant role in a more sustainable food chain as chemical pesticides are withdrawn due to resistance problems or because they are no longer commercially viable, according to the research. Chemicals also endanger workers' health and can contaminate groundwater.

"It is evident that biopesticides have a potentially important contribution to make to a competitive agriculture industry," said lead researcher, Professor Wyn Grant, at the University of Warwick. "They have the potential to increase consumer confidence in fruit and vegetables whilst moving away from a polarised and over-simplified choice between conventional and organic modes of production."

The research suggests that consumer concerns about toxic residues could undermine the recommended 'five a day' target for the consumption of fresh fruit and vegetables. Supermarkets have responded to consumer pressure by banning some approved pesticides, but have been slow to embrace biopesticides.

Biological control agents such as naturally occurring fungi, bacteria or viruses are applied in much the same way as chemical pesticides to fight insect pests, but have obvious benefits as they have little impact on other organisms, are compatible with other natural enemies, do not leave toxic residues and are relatively cheap to develop. These far outweigh the disadvantages of lower effectiveness and a shorter shelf life. So why has there been poor uptake in Britain?

The study says that because the regulatory system in the UK was developed with chemical pesticides in mind, it does not encourage the development of biopesticides. In recognition of this, the regulator - the Pesticides Safety Directorate (PSD) - lowered registration fees and created a Biopesticides Champion in 2006. This has led to a modest increase in the number of biological products being registered, with others in the pipeline.

The researchers pinpointed a lack of mutual recognition between EU member states as a key reason why the US has a much higher rate of biopesticide use. This makes it hard for the small companies – often start-ups – that usually develop biopesticides to obtain economies of scale.

New chemical formulations could be used to solve problems with biopesticide storage and efficacy and this might lead to greater interest from large businesses, the study says. Biopesticides need to be fitted into current environmental stewardship schemes to provide incentives for their use. Moreover, consumers need to be educated about biopesticides – and they should be given a different name with less negative connotations. The researchers also suggested providing an ethical marque for products.

Importantly, risks, costs and benefits need to be shared out between the manufacturer, regulator, government and consumers. The researchers also propose a framework to promote innovation within the regulator, including pressure from central government, the appointment of key individuals to drive through change, the need for regulators to develop their expertise and commercial or financial pressure.

"The absence of a Europe-wide market for biopesticides is a significant obstacle to their wider commercial availability," the researchers said, though moves are underway to remedy this. They also pointed to "patchy" interaction between the regulator and retailers, and a lack of involvement of environmental groups, which they put down to indifference rather than hostility.

Source : Economic & Social Research Council