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Use of biopesticides – A safe solution
Dr Chris KnightCampden 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 [email protected]