Growing Relay Species to Promote Biological Control
1. Presentation
Characterization of the technique
Description of the technique:
Cornflowers in a wheat field
| Céline Géneau | Fibl (Switzerland) | celine.geneau(at)fibl.org | Frick, Switzerland |
|---|---|---|---|
| Jean-Pierre | ENSAT | sarthou(at)ensat.fr | Castanet-Tolosan (31) |
| Régis Wartelle | Regional Chamber of Agriculture of Picardy | r.wartelle(at)picardie.chambagri.fr | Amiens (80) |
| Julien Halska | INRA | julien.halska(at)grignon.inra.fr | Dijon (21) |
Sowing (or planting) attractive species in plots with the aim of attracting auxiliaries, either sporadically within the plot or in regularly spaced rows. These are mostly flowering plants for the majority of auxiliaries, but also herbaceous plants for predatory beetles. This technique was initially practiced in market gardening under greenhouse conditions. These relay plants can sometimes also favor the targeted pest or other species. This undesirable effect can be limited by a judicious choice of the relay species, notably their ability to attract and feed auxiliaries (nectar accessibility) and their low competitive ability.
Example of implementation: Examples of reservoir plants: fava bean, phacelia, dill, coriander, buckwheat, vetch, great ammi, cornflower, rue. Some, like the cornflower, produce nectar on the outer side of the flower (external face of the sepals at the floral bud stage). This resource is therefore available over a longer period and is more accessible, which is much more effective for promoting biological control.
Implementation period On established crop
Spatial scale of implementation Plot
Application of the technique to...
All crops: Not generalizable
So far, the only recorded example is the introduction of cornflowers in cabbage fields. There seem to be examples in cereals.
All soil types: Easily generalizable
Provided that the relay species are adapted to the pedological context.
All climatic contexts: Easily generalizable
Provided that the relay species are adapted to the climatic context.
Regulation
2. Services provided by the technique
3. Effects on the sustainability of the cropping system
"Environmental" criteria
Effect on air quality: Increasing
Phytosanitary emissions: DECREASE
GHG emissions: NEUTRAL
Effect on water quality: Increasing
Pesticides: DECREASE
Other: No effect (neutral)
There is an improvement in air and water quality as there is a reduction in pesticide use linked to increased pest regulation by auxiliaries, and these pesticides are likely to be transferred into air and water.
There is no effect on fossil energy consumption and CO2 emissions, except in case of specific passes for the establishment of relay plants.
Biodiversity:
Relay plants are food sources for auxiliaries that we want to attract into the plot, but also for other insects. Birds that feed on insects or seeds may also be favored.
"Agronomic" criteria
Productivity: No knowledge on impact
An effect on productivity can be assumed in some cases, depending on the relay plant chosen. In FIBL trials (Swiss research center for organic farming, see bibliography), cabbage yields were higher with relay plants.
Soil fertility: No knowledge on impact
The effects of the root system and residue return depend on the species used as relay plants (notably whether they are legumes or not), their density, and the structure of their stand.
Water stress: No knowledge on impact
The effect depends on the density of relay plants.
Functional biodiversity: Increasing
An improvement in functional biodiversity is the goal of the technique, to amplify the biological control service. Effects on other potential services of functional diversity remain to be studied.
"Economic" criteria
Operating costs: Increasing
Cost of seeds or plants of service plants and cost of implementation (sowing, planting).
Mechanization costs: Variable
Depends on the mode of establishment of relay plants.
Margin: Variable
The effect on margin depends on the balance between the costs induced by the establishment of relay plants and the savings on treatments. In the absence of treatment against the concerned pest (for example in organic farming), an increase in margins can be expected. Marketing of relay plants can be considered (cornflower, buckwheat).
"Social" criteria
Working time: Increasing
Mechanization time depends on the mode of establishment of relay plants. In all cases, additional work is necessary for specific planting or for mixing seeds before sowing.
Observation time: No effect (neutral)
4. Favored or disadvantaged organisms
Favored Pests
| Organism | Impact of the technique | Type | Details |
|---|
Disadvantaged pests
| Organism | Impact of the technique | Type | Details |
|---|---|---|---|
| cabbage moth | MEDIUM | pest, predator or parasite | |
| black bean aphid | pest, predator or parasite | ||
| pea aphid | pest, predator or parasite |
Favored auxiliaries
| Organism | Impact of the technique | Type | Details |
|---|
Disadvantaged auxiliaries
| Organism | Impact of the technique | Type | Details |
|---|
Favored climatic and physiological accidents
| Organism | Impact of the technique | Details |
|---|
Disadvantaged climatic and physiological accidents
| Organism | Impact of the technique | Details |
|---|
5. For further information
- Promoting auxiliaries in cabbage fields
- -Balmer O.
FIBL, Professional report, 2010
- Improved fitness of aphid parasitoids receiving resource subsidies
- -Tylianakis J.M. (University of Canterbury, Lincoln University, New Zealand); Didham R.K. (University of Canterbury, New Zealand); Wratten S.D. (Lincoln University, New Zealand)
Ecology, Vol. 85, no. 3, pp. 658-666, Peer-reviewed article, 2004
Case studies with buckwheat in wheat
- Natural regulation at the farm level. Enhancing biological control - Habitat management to promote natural enemies of agricultural pests
- -Häni, F. J., E. F. Boller, et al.
University of California Press: 161-210, Peer-reviewed article, 1998
Case of sowing sunflower in maize (p. 188)
- Selective flowers to enhance biological control of cabbage pests by parasitoids
- -Géneau C. E. (FiBL, Lancaster University); Wäckers F. L. (Lancaster University, Biobest); Luka H. (FiBL, University of Basel); Daniel C. (FiBL); Balmer O. (FiBL, Swiss Tropical and Public Health Institute, University of Basel)
Elsevier, Peer-reviewed article, 2011
On laboratory screening of relay plants in the case of cabbage
6. Keywords
Pest control method: Cultural control
Mode of action: Action on initial stock
Type of strategy regarding pesticide use: Redesign
Annexes
S'applique aux cultures suivantes
Défavorise les bioagresseurs suivants
