Use of biopesticides – A safe solution

Dr Chris Knight

Campden BRI

Biopesticides - Introduction

• Insects, plant disease and weeds are major constraints to food crop production

• Becoming more difficult to control by conventional methods– Pesticide resistance, product withdrawals

• Need to control emerging threats

Biopesticides - Introduction

• Pressure to reduce residue levels from conventional chemical pesticides– Regulations: changes in MRLs– Retailers: minimise detectable residues

• Pressure to develop sustainable ‘pest’ control systems– Environmental welfare– Maintain crop quality, productivity and

profitability

Biopesticides - Introduction

• Integrated Crop Management (ICM) seen as the way forward (cf IPM)– Framework for reduced chemical pesticide

use and residue levels

• Combines complementary ‘pest’ control methods– Include chemical, biological, cultural and

physical controls, plant resistance and decision support systems

Biopesticides in ICM

• Make an important contribution to ICM– Help reduce reliance on chemical

pesticides

• Major role to play in sustainable farming– Conventional and organic systems– Reduce artificial chemical inputs

What is a biopesticide?

• Range of definitions and terminologies– Can be confusing– Essentially a broad group of agents

• Defined as– Mass produced– Biologically based agents– Used to control plant pests, diseases and

weeds

What is a biopesticide?

• ‘Biopesticide’ covers a wide spectrum of ‘products’– Subject to regulation as pesticides– Approved uses and conditions of use

• Living organisms as control agents– e.g. predatory insects– Not necessarily regulated as pesticide

products

• Three basic categories

Categories of biopesticides (1)• Products based on pheromone and

other semiochemicals– e.g. insect pheromones for trapping or

mating disruption

• Semiochemicals– Chemicals emitted by plants, animals and

other organisms (or synthetic analogues)– Evoke a behavioural or physiological

response in the same or similar species

Categories of biopesticides (2)• Products containing microorganisms

(microbials)– e.g. bacterium, fungus, virus

• Natural enemies– Includes invertebrates (e.g. predatory

insects) and nematodes– Not necessarily regulated as a pesticide

product

Categories of biopesticides (3)• Products based on plant extracts

– Unprocessed extracts representing a cluster of substances

– Highly refined containing one active substance

Categories of biopesticides (Other)• Genetically modified plants

– Express introduced genes that confer protection against pests and disease

• Not universally accepted as ‘biopesticides’

How many biopesticide products?• Wide variation in countries

– Over a 1000 products in USA– Significantly fewer in EU

• Microbial products– 200 in USA– 60 comparable products available in EU

Examples of biopesticides (UK)• Fungicide

– Bacillus subtilis (specific strain)– Coniothyrium minitans (specific strain)

• Insecticide– B. thuringiensis var. kurstaki– Cydia pomella granulosis virus– Verticillium lecanii– Spinosad– Fatty acids

Examples of biopesticides (UK)• Herbicide

– Citronella oil (plant extract)– Fatty acids

• Other– Candida oleophila (biological control)– Peniophora gigantea (tree stumps)– Pepper (vertebrate control)– Zucchini yellow mosaic virus weak strain

(immunisation)

Biopesticides - Benefits

• Usually inherently less toxic than conventional pesticides– Environmental and worker welfare

• Produce little if any residue– Food safety

• Generally have a narrow spectrum of activity– Low direct impact on non targets,

including humans and wildlife

Biopesticides - Benefits

• Use often compatible with other control agents

• May aid chemical pesticide performance when used together– Enhanced control– Help prevent/delay chemical pesticide

resistance

• Mode of action not specific– Reduced risk of developing resistance

Biopesticides - Benefits

• Used as a component of ICM may decrease use of chemical pesticides– Crop quality and yields remain high

• Flexible approach to ‘pest’ management– Natural enemies can reproduce in the pest

population and respond to changes

• Help meet market demands/expecations for– Environmentally friendly agriculture– Reduced chemical pesticide residues

Biopesticide - Concerns

• Commercialisation is affected strongly by the regulatory system– Governs their authorisation and use– Disincentive for manufacturers

• Industry is relatively small– Many SMEs– Policy resources limited– Undergoing organisational development

Biopesticide - Concerns

• Higher unit prices compared to chemical pesticides

• In general, biopesticides are not as effective as chemicals– Chemicals easier to predict what will do

• Biopesticides may not work immediately– Ecological background may have to

change first

Biopesticide - Concerns

• Shelf life may be shorter than chemicals

• Technical knowledge– Have to be used in relatively complex

knowledge intensive management systems

– To be used effectively users need to know a great deal about managing ‘pests’

– May act as a disincentive or influence efficacy

Biopesticides - Summary

• Comparisons between chemical and biopesticides are over simplistic– May detract from from beneficial

properties

• Becoming part of mainstream agriculture– agrochemical industry– Good Agricultural Practice

Biopesticides - Summary

• Make an important contribution to– Development of sustainable agriculture– ICM/IPM systems– Reducing reliance on chemical pesticides– Reducing pesticide residue levels in food– Meeting market demands and expecations

• Provide positive public benefits related to policy goals

Biopesticides - Summary

• Positive benefits– Environmental welfare– Food safety

• Wider commercial uptake requires collaboration between– Governments and regulators– Agrochemical industry– Farmers

Thank youc.knight@campden.co.uk