Installing Single-Plot Nets - Alt'Carpo in Orchard
1. Presentation
Characterization of the technique
Description of the technique:
Photo credit: J-M.Montagnon – La Pugère
Information initially sourced from the Guide for designing fruit production systems that are economical in phytosanitary products (2014) / Technical sheet no. 15. For more information: See link
Principle
This technique is a main lever to fight against the codling moth (Cydia pomonella) on apple and pear. It creates a physical barrier with a dual effect:
- an exclusion effect preventing codling moths from laying eggs on the plant,
- a disruption effect on the mating flight of adults under the net (mating disruption is less than with the single-row net).
The Alt'Carpo single-plot net technique consists of enclosing the entire orchard with a net (see GIS Fruits video example).
Means implemented
Equipment:
- Net with mesh size adapted to Alt’Carpo at least around the plot perimeter: 2.2 x 5.4 mm
- Trellising adapted for a hail protection structure
- Hermetic junction of nets from one row to another and on the edges. The crossed elastic system offers a good compromise.
Net color:
The darker the color (white/crystal, gray or black), the longer the lifespan. This favors amortization of the investment.
Conversely, the darker the color, the more the maturity is delayed due to shading: up to 8 days with black net.
Technique:
The technique consists of enclosing the entire orchard with a net with mesh adapted to the concerned pest (mesh 2.2 mm x 5.4 mm for the codling moth).
However, if a hail net is already installed, it is generally kept on the ridge and the plot perimeter is equipped with a net of Alt’Carpo mesh type. An access door and space to maneuver at the end of the row for agricultural machinery must be planned to avoid hindrance and allow normal work under the net.
Technical support is essential to size the net system according to the orchards.
Example of implementation:
Several implementation examples, as well as experiments and results, are available on the website www.alt-carpo.com
Details on the technique:
- The net must be closed before the flight of the pest (but after flowering/pollination because the net significantly reduces fruit set rates).
- It is interesting to combine the installation of an Alt'Carpo single-plot net with prophylactic measures such as: keeping access closed, including during harvest periods, removing fruit bottoms, fruits affected during thinning, avoiding wooden crates near plots and the presence of light sources.
- Monitoring consists of regular visual checks and trapping under the net.
Implementation period On established crop
Once installed, the Alt'Carpo net has a lifespan linked to the net color and the plant growth dynamics: from 5 to over 15 years. The ridge part of the net must be folded and unfolded at least once a year (fold at the end of codling moth flights and unfold just before the start of the 1st codling moth flight, after the pollination period and anti-frost spraying on foliage).
Spatial scale of implementation Plot
The orchard is fully enclosed
Application of the technique to...
All crops: Not generalizable
This technique cannot be generalized to all fruit species nor to all plots.
Indeed, the ideal plot must have a square or rectangular shape (no setback) to allow the installation of nets. At the same time, there must be enough space at the turning areas to install anchors and to be able to turn under the net with agricultural machinery.
For a plot with a crossed elastic system, a ridge height below 3.50 m is recommended. Thus, tree height also conditions the installation of this technique.
The technique has been tested on:
- Pome fruits: not effective on oriental fruit moth of peach (Grapholita molesta), a potential secondary pest in southern regions.
- Plum: against psylla (Cacopsylla pruni) (hail net on ridge and fine mesh 4 x 4 mm to close sides) but nets must be closed early, which poses pollination problems.
All soil types: Easily generalizable
Easily generalizable
No major constraints. However, since this technique requires a hail protection infrastructure, the soil must be suitable for anchors. Be careful with very light soils.
All climatic contexts: Easily generalizable
Easily generalizable
No major constraints. However, in windy conditions, plan a windbreak.
Regulation
The use of fine mesh nets around apple plots to create a physical barrier against codling moth is subject to a CEPP sheet (action no. 1: Protect apple orchards against codling moth using insect-proof nets).
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
Effect on water quality: Increasing
Pesticides: DECREASE
Effect on fossil resource consumption: Increasing
Fossil energy consumption: INCREASE
Other: No effect (neutral)
Environmental impacts related to net manufacturing (use of petroleum products), their transport and recycling (recycling channels poorly developed depending on regions but being established with Adi.valor). For more information see link
Other comments
Obvious effects on drift reduction. Decrease in negative impacts on air and water quality (less insecticides: 1 to 3 IFT vs orchard in mating disruption in the southeast, 12 IFT vs chemical cover; windbreak effect of the system)
Climatic effect of nets: can reduce irrigation water quantities (maintaining humidity and soil moisture)
"Agronomic" criteria
Productivity: Variable
Variable
This technique has no direct effect on productivity. But in some conditions, indirect effects of the technique (protection against hail, reduction of negative effects related to wind, reduction of sunburn on fruits, limitation of bird damage, etc.), combined with good efficiency in controlling codling moth, can allow an increase in marketable yield compared to plots not covered by nets.
However, if shading related to the hail net is significant (example of black net), varieties sensitive to this phenomenon (case of Granny Smith and clones) have difficulties setting fruit, or even suffer flowering return deficits.
Production quality: Variable
Variable
Improves fruit skin quality because Alt’Carpo nets protect against sunburn, woodiness, roughness.
Beware of reduced light, especially with certain net colors (gray and black), which can reduce fruit coloration and sugar content, especially in more northern regions. Lack of light can thus impact fruit maturity and shift harvest date, reducing market value (reduction in first-choice rate at packing station).
Soil fertility: No effect (neutral)
No effect (neutral)
Water stress: No knowledge on impact
No knowledge on impact
Functional Biodiversity: Variable
Variable
Reduction in insecticides favors development of beneficials.
On the other hand, the net reduces predation of voles by foxes and birds of prey. The net can also reduce the ability of some microhymenoptera such as (Aphelinus mali) to develop.
"Economic" criteria
Operating costs: Variable
Variable
In 2012, installation cost was around €9000 to €12000. The initial investment seems high but the net lifespan of 10 to 15 years plus benefits associated with crop protection against codling moth, some climatic accidents, bird damage and reduced insecticide expenses contribute to faster amortization of the high initial cost.
Mechanization costs: Variable
Variable
Mechanization related to installation of infrastructure and nets, as well as operations to fold and unfold nets: except for installation of the fixed plot perimeter (fixed), it is identical to managing a hail net. However, fewer interventions for chemical treatment of the plot.
Margin: Variable
Variable
This will mainly depend on:
On one hand, codling moth pressure and damage such as sunburn, hail, birds, etc. in the concerned orchard.
On the other hand, net longevity (reduction or extension of amortization period).
"Social" criteria
Working time: Variable
Variable
If a hail net already exists on the plot, mechanization time will not change significantly. In this case, there will be a slight increase in time related to installation of the plot perimeter.
However, both the hail net and the Alt'Carpo net require manual work time investment to fold, unfold and possibly repair the net each year.
This technique requires opening and closing the access door to the netted orchard at each cultural intervention. Possibility of an automatic door type fridge door strips.
Peak period: Increasing
Increasing
Unfolding nets in spring corresponds to a fairly critical period for work time management on pome fruit farms. This increase occurs after flowering.
Observation time: No effect (neutral)
No effect (neutral)
A slight increase due to system integrity checks. However, this increase is not very significant compared to monitoring recommended in all cases.
4. Organisms favored or disfavored
Favored Pests
| Organism | Impact of the technique | Type | Details |
|---|---|---|---|
| common vole (Microtus arvalis) | pest, predator or parasite | Reduced predation of voles due to exclusion of foxes and birds of prey by the net. | |
| Mediterranean pine vole (Microtus duodecimcostatus) | pest, predator or parasite | Reduced predation of voles due to exclusion of foxes and birds of prey by the net. | |
| water vole (Arvicola terrestris) | pest, predator or parasite | Reduced predation of voles due to exclusion of foxes and birds of prey by the net. |
Disfavored pests
| Organism | Impact of the technique | Type | Details |
|---|---|---|---|
| Codling moth (Cydia pomonella) | STRONG | pest, predator or parasite | |
| Bird (pest) | pest, predator or parasite | This technique limits bird damage on fruits | |
| Leopard moth (Zeuzera pyrina) | pest, predator or parasite | The Alt'Carpo net limits development of leopard moths |
Favored Beneficials
| Organism | Impact of the technique | Type | Details |
|---|---|---|---|
| Spiders | Natural enemies of pests | Generalist predator | |
| Ladybugs | Natural enemies of pests | Predator of aphids |
Disfavored beneficials
| Organism | Impact of the technique | Type | Details |
|---|---|---|---|
| Birds of prey | Natural enemies of pests | Predator of voles | |
| Foxes | Natural enemies of pests | Predator of voles |
Favored climatic and physiological accidents
| Organism | Impact of the technique | Details |
|---|
Disfavored climatic and physiological accidents
| Organism | Impact of the technique | Details |
|---|---|---|
| Sunburn | ||
| Hail | ||
| Wind |
5. For more information
- Alt'Carpo - An alternative that says "stop" to codling moth
- -Vaucluse Chamber of Agriculture - Filpack, Website
- Alt'Carpo nets
- -Séverac G.
Vaucluse Chamber of Agriculture, La Pugère Experimental Station, Technical brochure, 2012
- Protection of apple orchards against lepidoptera
- -Koké E., Biargues M-E., Sagnes J-L., Loquet B., Westercamp P.
CTIFL Infos, no. 270, Technical brochure, 2011
6. Keywords
Pest control method: Physical control
Mode of action: Action on initial stock Barrier
Type of strategy regarding pesticide use: Substitution
Annexes
S'applique aux cultures suivantes
Favorise les bioagresseurs suivants
- Common vole (Microtus arvalis)
- Mediterranean pine vole (Microtus duodecimcostatus)
- Water vole (Arvicola terrestris)
Favorise les auxiliaires
Défavorise les bioagresseurs suivants
Défavorise les auxiliaires
Défavorise les accidents climatiques
