Biopesticide regulation and performance for cereals and oilseeds

Biopesticides are regulated as plant protection products. However, they have specific usage requirements to maximise their efficacy.

There’s a growing interest in alternatives to conventional synthetic chemistry in all cropping systems.

For example, this is due to:

• Regulatory changes, with active substances and products restricted or withdrawn
• Pesticide efficacy changes, due to resistance in target organisms
• Increased interest in lower-impact crop protection, as part of integrated pest management (IPM)

Products used to control pests, diseases or weeds in crops usually fall under pesticide legislation and are subject to safety and efficacy assessments.

This is true whether active ingredients are synthetic or come from a biological source.

Great Britain (GB) follows retained EC regulation 107/2009 (legislation.gov.uk) and Northern Ireland follows the EU plant protection product regulatory system.

The Health and Safety Executive (HSE) divides biopesticides into four product categories:

• Pheromone and other semiochemical
• Microbial, such as those based on a bacterium, a fungus or a virus
• Plant extracts, which includes botanicals
• Other novel alternative products

Although biopesticides must meet the same standards as conventional products, the data requirements and risk assessments may be adapted to reflect the biological nature of the active substances.

For example, microbial products require the assessment of specific factors, such as pathogenicity, infectivity, toxin production, persistence and potential multiplication in the environment.

When an active substance is deemed to have a minimal impact on human and animal health and the environment, it is classified as ‘low risk’.

Such substances may receive a longer initial approval period, compared to standard active substance approvals.

There are very few low-risk products authorised for use in cereal or oilseed crops, but those available tend have a natural origin.

But ‘natural’ does not automatically mean safer or more effective.

Some authorised products with a natural origin do not meet low-risk criteria.

Products based on living invertebrate biological control agents, such as beneficial insects, nematodes and mites, are not regulated as plant protection products.

Basic substances also do not go through the full active substance approval process.

Often of natural origin, such substances may have value for plant protection, but they are not placed on the market primarily as a plant protection product.

There are over 20 basic substances on the GB approvals register, which include chemical compounds, such as sodium chloride, and food-grade substances, such as mustard seed powder.

Such substances are not considered to be of concern, in terms of health and environmental impacts.

Biopesticides are marketed for a range of crop protection uses, with a small number now available for use in cereals and oilseeds.

Their performance depends on the interaction between the crop, the pathogen or pest and the wider farming system.

Compared to conventional chemistry, biopesticide products may be relatively sensitive to changes in:

• Temperature
• Moisture and humidity
• UV levels
• Crop growth stage
• Pest or disease pressure

The horticultural sector has led most biopesticide innovation.

In UK arable crops, there is greater uncertainty about how biopesticides may perform.

However, plant protection product labels can only make control claims if the authorisation holder/marketing company submitted sufficient evidence to back them up.

It means you can have confidence in any product authorised to target specific pests in particular cropping situations, providing you follow the usage information on the label.

Labels include guidance on how to maximise product performance.

As microbial products are based on living organisms, they often need particular care.

Because of their sensitivity, biopesticides are often most effective when used as part of a wider IPM strategy.

A combined approach, based on biological and conventional options, may be greater than the sum of its parts and contribute to resilient crop protection programmes.