Codling moth exclusion netting: an overview of French and Italian experiences Aude Alaphilippe1, Yvan Capowiez2, Guilhem Severac3, Sylvaine Simon1, Marc Saudreau4,5, Stefano Caruso6, Stefano Vergnani7 1 INRA, UE 0695 Recherches Intégrées, Domaine de Gotheron, 26500 Saint-Marcel-lèsValence, France ;
[email protected]. 2 INRA, UR1115 PSH Plantes et Systèmes de Culture Horticoles, Agroparc, 84914 Avignon Cédex 9, France 3 CA84, Chambre d'agriculture de Vaucluse, 84912 AVIGNON Cedex 9, France 4 INRA, UMR 547 PIAF, F-63000 Clermont-Ferrand, France 5 Université Blaise Pascal, UMR 547 PIAF, F-63000 Clermont-Ferrand, France 6 Consorzio Fitosanitario Provinciale. Via Santi 14, Modena, Italy 7 Centro Ricerche Produzioni Vegetali (CRPV) – Cesena, FC, Italy
Abstract: Exclusion netting has been designed by the French extension services in 2005 to control the codling moth. Since 2009, the French and Italian Alt'Carpo networks have compared and shared their experiences about the efficacy of nets and their effect on pests and fruit production in both the French apple orchard and Italian pear orchards. The results indicated that netting represents an efficient way to control the codling moth and enables a significant reduction in pesticide use without any major risk for fruit production, harvest and quality. Keywords: Orchard, exclusion netting, physical control, codling moth, agronomic performances
Introduction The Rhone valley region (Southern France) and Emilia-Romagna region (Northern Italy) are two important pomefruit orchard areas of Europe. Pomefruit orchards require the application of many pesticides, including a high proportion of insecticides specifically targeted towards the codling moth: 12 sprays on average in South-Eastern France apple orchards (Sauphanor et al., 2009) and 10-12 sprays including microbiological products in Emilia Romagna pear orchards (Boselli et al., 2013) are yearly applied. In this context, the French extension services designed in 2005 a non-copyrighted method named ‘Alt’Carpo nets’ to cover the entire tree canopy and protect fruits against codling moth; Alt’Carpo nets can be either single-row or whole-orchard white nets of mesh size 2.2 x 5.4 and/or 3 x 7.4 (Severac & Romet, 2008). Nowadays around 2000 ha are covered by the Alt’Carpo nets in Southern France and it was introduced in Italy on pear in 2008 (Caruso & Vergnani, 2010) with about 350 ha covered with nets. Nets deeply modify the agronomic context of orchards, including microclimate and biological aspects. In particular, as nets provide a high control of codling moth, most insecticides applied in orchards are therefore suppressed in netted orchards (Sauphanor et al., 2012) with possible effects on the arthropod pest complex and its natural control. Since 2009, the French and Italian Alt'Carpo networks have compared and shared their experiences about the effects of exclusion netting on pests and fruit production.
Material and methods Fruit damages, infestation and infection levels of pests and diseases were measured to evaluate the efficacy and possible side-effects of nets. Effects ffects of nets on the orchard microclimate,, as well as on the agronomic performances of netted orchards (tree growth, fruit production and quality) were also studied in both the French (apple orchard) and Italian (pear orchard) networks. French experiments On-farm farm experiments were conducted in an ‘Alt’Carpo’ network composed of 17 netted and 13 uncovered commercial apple orchards under either organic or IPM management. INRA carried out specific experiments exp with exclusion netting on the codling odling moth behavior to better understand the mode of action of this control method. method Climatic variables were also assessed to analyze potential effects of nets on tree physiology and arthropod dynamics. The pest complex (fruit damage and infestation levels), levels), including the rosy apple aphid (Dysaphis plantaginea), was studied under both organic and integrated management strategies. Italian experiments On-farm farm experiments were conducted in an ‘Alt’Carpo’ network composed of 6 netted and 6 uncovered commercial pear orchards under organic management.
Results Reduction in pesticide use and mode of action In both countries, a high level of efficacy of nets was observed against codling moth, especially for the ‘single-row’ row’ system. The use of nets permitted a significant decrease in insecticide use in orchards measured by the Treatment Frequency Index (TFI, sum across the season of the number of equivalent full-dose full dose applications of pesticide (Figure 1).
Figure 1. Treatment Frequency Index total and insecticides for orchards orchard with and without net. Left: French apple orchards and right: right Italian pear orchards.
In both the French and Italian on-farm network, the ‘single-row’ row’ netting system enabled enab a significant reduction ction in pesticide use without any major risks for the production. In France, insecticide nsecticide use was reduced from 13.7 TFI down to 4.1 with net, while fungicide use remained similar (13.4 and 14.8 TFI without and with net, respectively). ). In Italy, Italy insecticide use was reduced from 18 TFI down to 5 with net, while fungicide use remained similar (24 and 25 treatments,, respectively). respectively The mode of action of netting was proved to be twofold, first as a physical barrier preventing codling moth from reaching the tree and then, as a behavioural constraint limiting reproduction under the nets, above all under single-row single row nets (studied in France only, see Sauphanor et al., 2012). Side-effects on pests Netting did not ot favour the development of other pests and diseases, with the exception in France, of the rosy and woolly apple aphids as well as Grapholita molesta and Adoxophyes orana and, in Italy, of Metcalfa pruinosa and Tingidae, but requiring the application of specific insecticides in some cases only. Netting also protected fruits from sunburn, wind and hail, as well as from birds and, in Italy, from mirids (misshaped fruits), as presented in Figure 2.
Figure 2. Percentage of fruit damage on Italian pear orchard with and without net at harvest (six orchards per modality). Agronomic performances and climatic conditions Climate under the net was little but significantly modified with an average increase in temperature (+0.7°C) and a decrease in the Photosynthesis Photosynthesis Active Radiation (-10% ( and 15%, respectively in Southern France and Northern Italy), as well as a decrease in relative humidity (-2.3%) in Italy (Figure 3).
Figure 3. Effect of net on the Photosynthesis Active Radiation (PAR) in France, on the daily d temperature and on the relative humidity (%) in Italy (data 2011).
This could explain a delay of a few days (less than 5 days) for the harvest date of covered apple trees compared to control (in France only).. No significant modification of the tree architecture, neither of the fruit quality and orchard yield was observed provided trees were trained and shaped to be covered by nets, especially for single-row single row nets; nets planning the installation of nets at planting is the best option. option Inn the Italian pear orchards, the vegetative growth was slightly decreased.
Conclusion Netting etting represents an efficient way to control codling moth and enables a significant reduction in pesticide use without any major risks for the production. However, we we recommend using the ‘single-row’ row’ version of netting, as it is, up to now, more efficient and more durable than the ‘whole-orchard’ version. Due to the cost and constraints of netting, this method is to be privileged in areas where codling moth is difficult ult to control and/or where a double aim of antianti hail protection and codling moth control is targeted. Further improvements of the method to reduce the handling time of nets (including at hand-thinning hand thinning and harvest) and therefore to reduce the costs are in progress. Other trials on nets for the control of other important pests such as Cydia funebrana on plum orchards and Drosophila suzukii on cherry and soft fruit orchards, have recently started.
Acknowledgment The French study wass partly supported by the European Commission through the Seventh Framework Programme under grant agreement number: FP7-265865 FP7 (PURE PURE project). project We also thank the French office for Water (ONEMA) for funding this work within the frame of the
research call 2009 of the program "Risk evaluation and reduction of pesticides use", axis 3 of the French “Ecophyto 2018” plan, with the collaboration of P. Franck, C. Lavigne, D. Plénet, M. Siegwart, JF Toubon, JL Sagnes, C. Gros, L. Parisi, F. Angevin, C.Mazzia, M. Rault. The Italian study was supported by Emilia-Romagna Region with the project “Innovazione tecnica nella difesa del pero attraverso l'adozione di opportune reti anti insetto. Year 20112013”. Lead partner Cooperative “Ortofrutticola Valle del Reno”. Corporeno, Ferrara (Italy) with the collaboration of Consorzio Fitosanitario di Modena, Centro Ricerche Produzioni Vegetali, “ASTRA Innovazione e Sviluppo” and ErgoConsulting.
References Boselli, M., Caruso, S., Barbari, G., Vergnani, S., Scannavini, M., Tommasini, M. G. 2013: New strategies of IPM to control codling moth in pear orchards. Meeting “Future IPM in Europe” Riva del Garda, Italy Caruso S., Vergnani S. 2010. Reti protettive anti-carpocapsa:facciamo il punto. Rivista di Frutticoltura 3/2010: 62-64. Sauphanor, B., Dirwimmer, C. et al. 2009: Analyse comparative de différents systèmes en arboriculture fruitière. In: INRA (ed.) Ecophyto R&D : vers des systèmes de culture économes en produits phytosanitaires. Rapport d'Expertise Collective Inra, Tome IV, 68 p. Sauphanor, B., Severac, G., Maugin, S., Toubon, J. F., Capowiez, Y. 2012: Exclusion netting may alter reproduction of the codling moth (Cydia pomonella) and prevent associated fruit damage to apple orchards. Entomol Exp App. 145(2): 134-142. Severac, G. & Romet, L. 2008 : Alt’carpo, une alternative efficace. Phytoma 612 : 18-20.
