Use of biopesticides – A safe solution Dr Chris Knight Campden BRI.
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Transcript of Use of biopesticides – A safe solution Dr Chris Knight Campden BRI.
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 [email protected]