Defining the Weed Control Campaign Strategy Based on Risk
Develop a weed control program (chemical or mechanical) based on several factors: observed or expected infestation (predominant weeds species in the plot), crop succession and the place of plowing in the rotation, sowing date. This method allows choosing the number of treatments (or possible skip), products, doses or mechanical weeding tools.
Example of implementation:
Example for a sunflower followed by a wheat, knowing that thistle is a problem in the plot. The herbicides available for this weed in sunflower are expensive, not very effective and have a poor environmental profile, whereas in wheat, they are cheaper, effective and have a better environmental profile. It is therefore advised not to treat in the sunflower.
Technical details:
The DECID'Herb software largely inspired this sheet. There is currently a Web version accessible on request for testing purposes (databases need updating, which limits its operationality). Contact members of the former Biology and Management Unit of Weeds at INRA (https://www6.dijon.inra.fr/umragroecologie/).
Implementation period On established crop
Spatial scale of implementation Plot
Application of the technique to...
All crops: Easily generalizable
All soil types: Easily generalizable
All climatic contexts: Easily generalizable
Regulation
2. Services provided by the technique
3. Effects on the sustainability of the cropping system
"Environmental" criteria
Effect on air quality: Variable
phytosanitary emissions: DECREASE
GHG emissions: VARIABLE
Effect on water quality: Increasing
pesticides: DECREASE
Effect on fossil resource consumption: Variable
fossil energy consumption: VARIABLE
Other: No effect (neutral)
Pollutant transfer to water (N, P, phytosanitary ...): Decrease
Reduction by reducing the number of treatments and doses and lower toxicity of molecules, except if the cropping system causes a high infestation risk.
Pollutant transfer to air (N, P, phytosanitary ...): Decrease
Reduction by reducing the number of treatments and doses and lower toxicity of molecules, except if the cropping system causes a high infestation risk.
Fossil energy consumption: variable
Possible reduction if fewer passes.
GHG emissions: variable
Possible reduction if fewer passes.
Biodiversity: Increase
Increase in animal and plant biodiversity linked to reduced herbicide use.
"Agronomic" criteria
Productivity: No effect (neutral)
No effect on yields.
Soil fertility: Increasing
Pressure is reduced on macrofauna as well as on fungi and bacteria in the soil, so improvements in ecosystem services provided, notably soil fertility, can be expected.
Water stress: No effect (neutral)
Functional biodiversity: Increasing
The increase in biodiversity is linked to reduced herbicide use and also concerns functional biodiversity.
Other agronomic criteria: Variable
Active substance durability: Increase
The annual strategy can take into account the active substances (or their modes of action) used in previous years to vary them to limit the development of weed resistance.
"Economic" criteria
Operational costs: Variable
Variable depending on strategies implemented and particularly on the variation in weed control strategy cost (cost of products and volumes used, number of passes).
Mechanization costs: Decreasing
Possible reduction if fewer passes.
Margin: Increasing
Likely improvement since the approach allows to best reconcile cost and effectiveness of the weed control strategy, while considering its environmental impact.
Other economic criteria: Variable
Fuel consumption: Decrease
Possible reduction if fewer passes.
Long-term weed control cost: Decrease
Reduction of long-term weed control cost via reduced risk of herbicide resistance development (which may require expensive molecules). Moreover, optimized effectiveness of annual weed control strategies will likely limit the soil seed bank.
"Social" criteria
Working time: Variable
Possible reduction if fewer passes.
Observation time: Variable
Slight possible increase. Need to know the weed flora of different plots.
4. Organisms favored or disadvantaged
Favored Bioagressors
| Organism | Impact of the technique | Type | Details |
|---|
Disadvantaged bioagressors
| Organism | Impact of the technique | Type | Details |
|---|
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. To learn more
- DECID'Herb: a decision support software for choosing a control method for environmentally friendly agriculture.
- -Munier-Jolain N. (INRA)
Seminar "Modeling for reasoned protection" RMT Modeling - INRA PIC/PI Network, May 21, 2008, Conference proceedings, 2008
link to the slideshow. The DECID'Herb software inspired this sheet. Unfortunately, it is not available due to lack of updates.
6. Keywords
Bioagressor control method: Chemical control
Mode of action: Rescue
Type of strategy regarding pesticide use: Efficiency
Annexes
La version initiale de cet article a été rédigée par Laurence Guichard, Julien Halska et Sébastien Minette.
| Laurence Guichard | INRA | laurence.guichard(at)grignon.inra.fr | Grignon (78) |
|---|---|---|---|
| Julien Halska | INRA | julien.halska(at)grignon.inra.fr | Epoisses (21) |
| Sébastien Minette | CRA Poitou-Charentes | sebastien.minette(at)poitou-charentes.chambagri.fr | Lusignan (86) |
