Presentation

Characterization of the technique

Description of the technique :

Photo credit : INRA Gotheron

Information originally from the Guide for the design of fruit production systems sparing in phytopharmaceutical products (2014) / Technical sheet no.14. For more information: see link

Principle

This technique is a main lever to fight against the codling moth (Cydia pomonella) and the oriental fruit moth (Cydia molesta) on apple and pear, against the cherry fruit fly (Rhagoletis cerasi) and against Drosophila suzukii on cherry tree. It creates a physical barrier with a dual effect :

an exclusion effect of these insects laying eggs on the plant or in the fruits;
a disruption effect on the mating flight of adults under the net.

The single-row net technique consists of wrapping each row of trees with a net with mesh size adapted to the targeted pest (see example video from GIS Fruits).

Means implemented

Equipment:

“Alt’Carpo” net with mesh size adapted to control the codling moth : 2.2 x 5.4 mm (white or gray recommended)
“Alt’Mouche” net with mesh size to fight against D. suzukii of 1.3 mm x 1.3 mm, or by default against the cherry fruit fly 2.2 mm x 3.4 mm. White color recommended.

Net color :

The darker the net color, the longer its lifespan. This favors amortization of the investment.

However, darker nets intercept more light radiation, making them difficult to use, especially on apple trees: less fruit coloration, reduced yields, impaired fruit set ...

Technique :

Each row of trees is wrapped with an “Alt’Carpo” net or an “Alt’Mouche” net.

The required width of the net corresponds to about twice the tree height plus 1 m.

Technical support is essential to size the net system according to the orchards.

Details on the technique :

The mesh type and installation date are very determinant for the method’s effectiveness. When possible, the use of these nets should be planned from the orchard design stage (trellising, anchoring, etc.).

Codling moth: the net must be closed before the start of codling moth flight (but after flowering/pollination because the net reduces fruit set rates)
Oriental fruit moth: on pome fruits, no need to cover the start of G1 because no sensitive organs before petal fall.
Cherry fruit fly: installation before adult emergence. Folding up as soon as the end of the annual generation (period management with [[:Category:Decision support tools|Decision Support Tools]).
D. suzukii: installation approaching veraison and until the end of harvest of the protected row.

The net can be installed even when insect pressure is quite high (damage remains low) for codling moth. In general, very good effectiveness regardless of the pest pressure level.

With this single-row net technique, its effectiveness is superior to that of the single-block net for codling moth: no entry points due to poor joints.

Monitoring consists of performing regular visual checks and trapping under the net.

Implementation is difficult on trees with volume forms (example of goblet-shaped cherry trees).

It is interesting to combine the installation of a single-row net Alt'Carpo / Alt’Mouche with prophylactic measures such as : removing the picking bottom, thinning damaged fruits, avoiding wooden crates near plots, managing net lifting during thinning or harvest operations.

Implementation period On established crops. The compromise linked to the choice of net color conditions the amortization duration.
Spatial scale of implementation Plot. Possibility to manage, row by row, the opening/closing of nets (different flowering, veraison or harvest dates). No constraint related to orchard size, unlike mating disruption which requires a minimum area to be effective.

Application of the technique to...

All crops : Sometimes difficult generalization

The technique can be applied to several fruit species : on apple, pear and cherry confirmed effectiveness. Under experimentation on peach, clementine, olive, table grape. The tree shape must allow net installation (more problematic with volume forms without significant production penalties).

This technique is currently under experimentation against:

Oriental fruit moth on peach
Green leafhoppers, Metcalfa, ceratitis, citrus leafminer on clementine (Civam organic Corsica)
Olive fruit fly (olive) (Regis and Roubal, 2011) : very interesting effectiveness but difficult implementation (costly), trial of nets around trees (individual net).

The method has also been tested on table grapes (Reynaud, 2013) against Eudemis with meshes of 1.38 x 1.38 and 3.4 x 3.2. Results showed effective protection but a negative impact on cluster quality (lack of coloration) because nets delay or block fruit maturity due to shading.

Regulations

Used net management with specific collection network, without the net being considered hazardous industrial waste (less than 100 mg of phytosanitary products/kg of net) (MSA Alpes - Vaucluse communication, May 2017 – data 2014 to 2016).

The use of fine mesh nets around apple tree rows to create a physical barrier against codling moth is the subject of a CEPP sheet (action no.1 : Protect apple orchards against codling moth using insect-proof nets).

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 : Variable

fossil energy consumption : VARIABLE

Additional details or comments :

Effect on air and water quality : No direct effect in the orchard, the net is not a source of air, water or soil pollution at the cropping system scale. Important indirect effect at a broader scale because the reduction in insecticide use enabled by Alt’Carpo and Alt'Mouche nets reduces negative environmental impacts linked to emissions of these products.
Effect on fossil resource consumption : Variable. Reduced use of phytopharmaceutical products (insecticides in this case) reduces fossil resource consumption related to manufacturing and transport of these products. Environmental impacts linked to net manufacturing (use of petroleum products), transport and recycling (recycling chain poorly developed depending on regions but being established with Adi.valor). For more information link to site

“Agronomic” criteria

Productivity : Variable

Production quality : Increasing

Improvement of fruit skin quality (reduction of russeting, sunburn, roughness…).

On cherry trees, protection allows harvesting fully ripe, shiny and homogeneous fruits, with increased picking speed (less waste).

Soil fertility : No effect (neutral)

Water stress : Decreasing

Functional Biodiversity : Variable

Reduced insecticide use favors the establishment of beneficials. However, the net can partially exclude some groups of beneficials.

“Economic” criteria

Operating costs : Increasing

Indicative cost 2012 : €6,000 to €10,000/ha (excluding labor)

However, durability about 10 years depending on maintenance, quality and color of the net (gray more resistant than white)

Mechanization costs : Increasing

Margin : Variable

Positive effect on turnover (less damage from hail, rubbing...). However, margin will also depend on the effectiveness of the technique on the targeted pest(s).

“Social” criteria

Working time : Increasing

Installation working time : 120 h/ha the first year.

Peak period : Increasing

Working time after installation: 70 to 100 h/ha/year to fold and unfold nets during manual operations (thinning, harvest...)

Observation time : Increasing

No direct access to the plant. Visual observations more difficult especially if annual shoots press against the net.

Favored or disadvantaged organisms

Disadvantaged pests

Organism	Type	Details
Codling moth (Cydia pomonella)	pest, predator or parasite	Nets are a main lever against this pest. More effective than single-block nets.
Drosophila (Drosophila suzukii)	pest, predator or parasite
Eudemis	pest, predator or parasite	Under experimentation on table grapes. Results show effective protection but negative impact on cluster quality (lack of coloration) because nets delay or block fruit maturity due to shading.
Citrus leafminer (Phyllocnistis citrella)	pest, predator or parasite	Under experimentation on clementine by Civam organic Corsica
Olive fruit fly (Bactrocera oleae)	pest, predator or parasite	Very interesting effectiveness but difficult implementation (costly), trial of nets around trees (individual net).
Cherry fruit fly (Rhagoletis cerasi)	pest, predator or parasite	Nets are a main lever against this pest
Bird (pest)	pest, predator or parasite	Nets limit bird damage
Oriental fruit moth (Cydia molesta)	pest, predator or parasite	Nets are a main lever to control this pest on apple and pear. Technique under experimentation on peach.
Leopard moth (Zeuzera pyrina)	pest, predator or parasite	Nets limit development of leopard moths

Disadvantaged climatic and physiological accidents

Organism	Impact of the technique	Details
Hail
Wind

For more information

(Some) effects of Alt’Carpo nets on natural regulation and some generalist predators.
-Capowiez et al.2014. Alt’Carpo Conference, 02/04/2014, Avignon. Link to presentation

Alt’Carpo
-Vaucluse Chamber of Agriculture - Filpack. Website Link to site

Contrasting effects of codling moth exclusion netting on the natural control of the rosy apple aphid. IOBC/WPRS Bulletin, 91, 81-85.
-Marliac G., Simon S., Fleury A., Alaphilippe A., Dib H., Capowiez Y. IOBC/WPRS, Peer-reviewed article, 2013. Link to article

Alt’Carpo nets.
-Séverac G. Vaucluse Chamber of Agriculture, La Pugère Experimental Station., Technical brochure, 2012. Resources, Collection 1 : Alternative techniques, document 1 C. Link to brochure

The Eudemis hits the nets. Réussir Fruits et Légumes, 326, 36-37.
-Reynaud C.2013

Protection of apple orchards against lepidopterans mechanical control with nets.
-CTIFL, Technical brochure, 2011. Infos Ctifl, April 2011, No. 270. Link to brochure

Use of mechanical protection to fight against olive fruit fly in southern France : results and perspectives.
-Regis S., Roubal C.2011. AFPP-4th International Conference on Alternative Methods in Crop Protection, Lille, 8-10 March 2011.

Keywords

Pest control method : Physical control
Mode of action : Action on initial stock Barrier
Type of strategy regarding pesticide use : Substitution

Appendices

S'applique aux cultures suivantes

Défavorise les bioagresseurs suivants

Défavorise les accidents climatiques

Hail
Wind

Installer des Filets monorang :Alt'Carpo / Alt'Mouche in orchard

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