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A framework for the practical use of semiochemicals in field crops - PS2107

Description
The main objective of this project is to develop a framework for the practical control of pests by means of newly available semiochemicals (chemicals that act as signals between organisms to cause natural behavioural or developmental changes) delivered by novel approaches suitable for use in field crops. The semiochemicals will principally be derived from plants and will provide either enhanced or reduced attractiveness, by non-host, masking or repellent effects. These effects will be combined to provide a push-pull strategy (directing pests away from crops to “trap” areas) for pest control, on a realistic agricultural scale for representative crop/pest interactions (colepterous pests of spring oilseed rape; cereal aphids; legume weevils/aphids). Delivery will not only be by direct application of the semiochemicals or release from plants, but also by use of natural plant activators to achieve the appropriate economy by causing crop plants themselves to release strategically required semiochemicals.

The project will also define and quantify the effects of the push-pull strategy on non-target species, with emphasis on natural enemies and other beneficial insects, some of which will also be exploited in the push-pull system by semiochemicals and habitat management. Thus, selected approaches for using enhanced attraction or repulsion will be employed, particularly using specific opportunities relating to the physiological properties of these crops and the system will consider the complete plant/pest/natural enemy complex.

The semiochemicals are identified and provided by PS2101, with delivery systems developed in PS2105. For the early milestones, such inputs to this project are from work in the previous Defra programme. The extent of the field trials will require further development as this project and the associated ones progress, particularly for natural plant activators and the approaches for their delivery. Depending on initial progress and naturally occurring pest levels, in later years supplementary farm trials would be needed to confirm ultimate practicality and cost.

This project will clearly demonstrate the circumstances under which semiochemicals can be deployed on a realistic agricultural scale as a component of integrated pest management. This will provide the first evidence of the opportunities for full scale push-pull based crop protection systems in the UK. The intrinsically benign nature of the semiochemicals selected, e.g. based on plant essential oils, and exploited in this work is highly relevant to the Government and Defra policies of minimising usage of conventional pesticides. This research is a necessary first step in encouraging further commercial development e.g. through LINK. The results will assist a wider move towards alternatives to broad-spectrum pesticides acting as toxicants and will inform the regulatory processes needed for semiochemical agents, particularly new plant activators.
Objective
Develop and demonstrate, on a realistic field scale, a push-pull strategy for the key combinable crops used in conventional arable rotation i.e. cereals and oilseed rape/legumes. Although the objective is to target the major crop/pest complex for each crop i.e. oilseed rape/Coleoptera, cereals/aphids and legumes, both aphids and Coleoptera, collateral effects of the strategy on other pests e.g. cereals/gout fly and the potential impact on non-target organisms, particularly beneficials, will also be investigated.
The overall objective will be divided into 2 sub-objectives as follows

1. Using plant derived and other semiochemicals that provide enhanced attractant and non-host/masking/repellent cues to devise and test on a realistic agricultural scale, a push-pull strategy for the pests of the representative brassica crop, spring oilseed rape (SOSR). Define and quantify the effects of the strategy on non-target species, particularly natural enemies and other beneficial insects. (Spring rape chosen to maximise natural occurrence of coleopterous pests)

2. Use plant derived and other semiochemical stimuli that provide enhanced attractant and non-host/masking/repellent cues under field conditions for target pests to formulate an integrated crop protection strategy for the other combinable crops used in conventional arable rotation i.e. cereals (winter wheat chosen to utilise best existing knowledge of predatory and parasitic insects) and legumes (chosen to target both coleopterous and aphid pests). Define and quantify the effects of the strategy on non-target species, particularly natural enemies and other beneficial insects.

Project Documents
• Final Report : A framework for the practical use of semiochemicals in field crops   (2407k)
Time-Scale and Cost
From: 2003

To: 2006

Cost: £307,500
Contractor / Funded Organisations
Rothamsted Research (BBSRC)
Keywords
Arable Farming              
Crop Pests              
Crops              
Farming              
Fields of Study
Pesticide Safety