Regulating for safe biocontrol

Countries that export horticultural produce must satisfy increasingly selective consumers. Purchasers demand produce that is not only blemish-free but free of pesticide residues. Traders are also under increasing international pressure to comply with ever tighter monitoring and control procedures on pesticide use. However, the challenge is to grow quality crops that meet environmental standards. Biopesticides, naturally occurring substances that control pests (including plant extracts and microbials) offer a promising alternative, as reported elsewhere in Focus on. Encouraging progress has been made in Kenya and most recently in Ghana, in achieving legislation for registration of biocontrol agents.

Over recent years biocontrol has proved to be a promising alternative to chemical pesticides. Agreement on protocols for testing and using biopesticides has, however, initially delayed their rapid development and more widespread use.

Proving safety

The testing procedures for ensuring safe use of chemical pesticides have been refined over the 50 years since their introduction. It has become an exacting but also very expensive process, affordable only by the largest manufacturers. Their costs have been recouped by sales of materials for use on large crop acreages, and often against more than one target pest or pathogen. Biocontrol products (BCPs) using naturally occurring agents such as botanical products (neem and pyrethrum extracts) and beneficial organisms, however, are frequently specific to a single pest or disease. They also tend to be used on horticultural crops grown on much smaller acreages, with less opportunity to recoup costs. Subjecting them to the same rigorous and costly testing procedures is not realistic, especially as BCPs are often developed by small companies or research teams that do not have the financial resources to pay for such work.

This point was stressed by David Grzywacz of the Natural Resources Institute, UK, when, at a workshop on registration for biocontrol agents in Kenya in 2003, he said, "The registration of biopesticides poses a particular challenge and inappropriate regulation can seriously impede the adoption of biopesticides, denying farmers access to a potentially valuable natural resource. India and Thailand have allowed candidate products to be developed to an advanced stage where their technical validity can be judged before any registration procedure is involved."

Indian and Thai authorities also generally exclude indigenous beneficial organisms from pesticide registration, as they are considered a safe part of the natural ecosystem. However, introduction of exotic organisms is subject to the protocols for regulatory testing developed by the UN Food and Agriculture Organisation (FAO). In both countries, biopesticides have been developed as local solutions to serious pest problems, along with parasitoids and pheromones, thereby increasing IPM options for growers.

Drawing on expert opinion and advice provided by partner institutions at the 2003 workshop, Kenya was able to develop a groundbreaking legislative framework for the use of natural pest control agents. This has proved more advanced than is currently in place in the UK and has enabled Kenyan companies to start mass production of biocontrol agents for major horticultural pests, (see A 'mitey' good approach to biocontrol). It has also allowed Kenyan growers to import biocontrol agents from elsewhere, particularly from South Africa. A further consultative workshop held in Arusha brought together participants from Kenya, Tanzania, Uganda, Ethiopia and Senegal and many showed an interest in adopting a similar framework.

In Ghana, where NRI* has been promoting IPM in peri-urban food crops and proposing refinements to the regulation of biopesticides, there is potential for the use of the baculoviruses of pests such as Helicoverpa armigera, Plutella xylostella and the Spodoptera species. Led by Kenya's success, the Ghana Environmental Protection Agency's product registration guidelines have been modified and will now be adopted for the registration of biopesticides. Ivory Coast and Togo have also been involved in the Ghanaian process and it is hoped that they too will be encouraged to adopt such guidelines.

Treating like with like

Different classes of biopesticides (botanicals, baculoviruses) require different approaches for testing but all materials or organisms within each group (eg all botanicals) can and should be treated equally. Rules applied to different classes should obviously include FAO and WHO classifications. International agreement on protocols would not only provide a 'level playing field' thereby reducing disagreements and delays. It would also build confidence in products that appear to offer a new way forward for pest management.

The registration of biopesticides often poses a particular challenge to regulatory authorities, as their evaluation requires different expertise to that needed for chemical pesticides. "Registration authorities are typically staffed by scientists whose primary expertise is in chemistry and chemical toxicology," says David Grzywacz, "whereas for biopesticides, some expertise is required in microbial ecology as well as bacteriology, virology and protozoology in order to understand their biology and assess their possible impact on the environment."

The primary role of regulation and registration is the protection of humans, domestic and wild animals, and the environment. In addition, registration aims to protect lawful trade and commerce. It is therefore necessary to balance the need for safety with the need to promote new safer technologies. The experiences of countries such as Ghana, Kenya, India and Thailand, as well as the US and EU, offer a basis from which to move forward. To quote David Grzywacz again, "The challenge is to put in place a registration system that will allow the rapid and efficient registration of useful effective biopesticide products while protecting farmers from ineffective ones."

* project led by Andy Cherry