Use of biopesticides A safe solution Dr Chris

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 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 you c. knight@campden. co. uk