Entomological and functional role of floral strips in an organic apple orchard: Hymenopteran parasitoids as a case study

Habitat manipulation techniques improve the availability of resources required by natural enemies to increase their effectiveness. This study focused on the effects of floral strips on Hymenopteran parasitoid presence. The experiments were conducted during spring 2007 in one organic low-input apple orchard located in south-eastern France. The density and the diversity of parasitic wasps collected from sown floral strips were higher than those from mown plants. The family of parasitic wasps of Braconidae was strongly dominant, followed by Mymaridae and Pteromalidae. By studying 26 flowering species, the greatest diversity and density of parasitic wasps were collected from Potentilla reptans, Achillea millefolium, Trifolium repens and Torilis arvensis. In terms of the early flowering plants, the most important results were observed in Euphorbia helioscopia, Senecio vulgaris and Veronica persica. To give an idea of the functional role of these plants, we studied the parasitic wasps of the diapausing larvae (cocoon) of codling moth Cydia pomonella. We recorded three emerged species: Ascogaster quadridentata, Pristomerus vulnerator and the hyperparasite Perilampus fulvicornis. However, none of these species have been observed on the 26 studied plants. Hence, this result may be suggesting that the studied plants do not have a functional role concerning these parasitoids. These studies may be advantageous for biological control programs in order to select flowering plant species attracting parasitic wasps specific to fruit pests

Differentes Strategies de Maitrise de la Tavelure du Pommier

Apple scab remains one of the main disease, responsible for significant economic losses. Selection of tolerant varieties is a promising way to follow, but is not yet giving satisfying results. Thus, different strategies have to be developed and enhanced: the screening of alternative control inputs, with lower copper dosage or without any copper is essential for short term answers to growers. This research give interesting results and potential new ingredients, however not as efficient as copper sulphate. Simultaneously, biology of the fungus permits a more preventive strategy, by destroying leaves at fall season, and thus highly decreasing the scab infection potential. Results of four trials led by CTIFL (copper alternatives) and GRAB (leaves reduction) are resented and discussed

Agroforestry Market Gardening: A Strategic Choice ToImprove Sustainability In Agroecological Transition?

Agroforestry mixing fruit trees and organic diversified vegetable is currently experiencing strong growth in France. The SMART project aimed to (i) explore the sustainability of these systems, (ii) assess the effects of synergies and competitions generated by agroforestry, as perceived by the farmers. Surveys and observations carried out among farmers showed that these systems were implemented by farms involved in short food supply chains. Diversification of products was therefore a central justification for the intercropping of fruit trees and shrubs with vegetables. The majority of farmers considered that intercropping fruit trees and vegetables did not create a problem for workload organisation or competition. Their certainty in this respect was rather limited, given the generally short duration of their experience. A global assessment of their satisfaction integrating technical, agronomic, environmental or socio-economical dimensions (see results) led most of them to consider that the choice of agroforestry was fully justified and could be recommended to other market gardeners. These results showed the need, when evaluating such systems, to adopt dynamic and holistic viewpoint on the different performance levels, allowing to consider the evolution of the trade-offs between pros/cons of such systems on the long-term basis

Un nouveau ravageur menaçant pour les cultures fruitières biologiques : Drosophila suzukii

A new pest has been officially described in France in 2010. Drosophila suzukii (also called Spotted-wing Drosophila) attacks many species of fruits, before ripening, and economic consequences are very important. Because of a very high fecundity and a great lack of knowledge on this invasive pest, there is a high need of applied research to provide efficient techniques to conventional and also organic farmers. Indeed, organic cherry or strawberry production is directly threatened by this new pest. The poster presents different control strategies and state of art for each of them

Assessment of the susceptibility to pests and diseases of 36 apple cultivars in four low-input organic orchards in France

One of the keystones of the organic orchard is the cultivar choice as one element of pest and disease control. However, few exhaustive data sets concerning the cultivar susceptibility to pests and diseases are available for growers. In order to identify cultivars adapted to organic production methods, the susceptibility to scab, aphids and powdery mildew and the agronomic properties of 36 cultivars were assessed in four French sites under different pedo-climatic conditions. Different levels of susceptibility to scab were observed for 23 scab Vf-resistant and 13 other cultivars. In the North of France where Vf resistance is overcome, the Vf cultivars displayed different levels of scab severity. A high variability in the susceptibility to aphids was observed whereas susceptibility to powdery mildew varied less. The analysis of susceptibility properties, yield and fruit quality, fruit storability and tree behaviour permitted to identify a set of interesting cultivars according to the site

Biodiversity and pest management

Maintaining biodiversity and the associated ecosystem services is an objective of the European Union, implemented through agri-environmental programmes. Biodiversity decline is occurring at a worldwide scale and has twofold implications. From a conservation point of view, the number of extinct and endangered species increases, and this impoverishment of natural ecosystems reduces their resilience. From an agronomical point of view, reduction of biodiversity affects processes that hamper crop productivity, such as pollination or pest management, being the consequence of this biodiversity decline a reduction in agroecosystem sustainability. But both, ecosystem resilience and agro ecosystem sustainability are not isolated. In the case of pest control, in many cases it is assumed that it depends on biodiversity. However, a positive relationship between biodiversity of natural enemies and pest suppression is not always the case. In fact, in some cases this relationship does not occur (Fig.1), and the success of biological control depends not on biodiversity, but on the presence of one or only few species of natural enemies. As an example, in the case of olive trees, a single species such as Anthocoris nemoralis or relatively simple predator assemblagesare associated with better biological control than complex assemblages (Paredes et al., 2015). However, it seems that the general rule in different agroecosystems is that biodiversity rather than abundance of natural enemies is linked to pest control, although this has been proven mainly in annual crops and in non-mediterranean environmental conditions (Dainese et al., 2019)

Quelle sélection fruitière pour une production durable, à faible niveau d’intrants ? Méthodologie pour un réseau de sélection variétale décentralisée

In France Fruit production is cultivated on 140 thousand hectares, mainly conducted on intensive training system. Very few elements are available on low input training systems while they have to integrate the Global rule under the frame of Ecophyto 2018. In order to evaluate if another system of cultivation will be possible, a project has been developed to highlight the main factors to be integrated in low input training system. A low input multilocal experimental design has thus been investigated on apricot in two main regions of production: Rhone valley and Roussillon. A set of 9 common cultivars with 20 replications each, planted in a complete single-tree randomization design has been established. As already observed in apple orchard, a larger set of disease has been observed in our experimental plots by comparison with conventional training orchards. A large genetic variability has been set-up among the observed cultivars, but if some of them expressed components of resistance against the observed diseases no one appeared widely resistant to all the diseases. Taking in consideration the longevity of the orchard, a huge concern exists with the tested germplasm because the observed dieback was in between 10 and 80% of the trees according to the cultivars after only 6 years of observation. On the methodological point of view, a clear optimization of the experimental design is expected on the base of the observed results

Assessment of diseases susceptibility of peach cultivars in experimental plots and on-farm for organic and low-input systems. Baseline of French case studies

Despite a high turn-over of new peach cultivars, their suitability for organic and low-input systems remains unknown for most of them. Diseases susceptibility is an important criteria to consider since diseases control is a bottleneck to peach production in theses systems. Since 2001, 81 peach cultivars were assessed in 2 experimental sites and 7 on-farm plots

Monitoring methods adapted to different perceptions and uses of functional biodiversity: Insights from a European qualitative study

The role of functional biodiversity for favouring natural regulation and reducing pesticide use in fruit production is generally acknowledged. Although a number of farmers attempt to favour biodiversity through different strategies (e.g. diversified hedges, nesting boxes), they often lack means to evaluate how their actions contribute in practice to functional biodiversity. We assumed here that to create useful and appropriate monitoring methods, it is necessary to take into account the variety of knowledge, perceptions and interests about functional biodiversity. To test our hypothesis, we adopted a comprehensive and participative approach based on interviews and workshops with farmers, advisors and field agronomists involved in apple orchard management. Our objective was to understand their different perceptions and uses of functional biodiversity and then, to design monitoring methods adapted to those perceptions and pre-existing uses. Our findings revealed both a plurality of perceptions of functional biodiversity along with a diversity of objectives and uses of monitoring methods. Based on these results, we identified four main attitudes towards the management of functional biodiversity: the wait-and-see attitude, the naturalist attitude, the regulation attitude and the multifunctional attitude. These attitudes do not correspond to person's profiles, since one person can adopt different attitudes in regard to different biodiversity components or in regard to the different practices supporting biodiversity. In addition, attitudes can vary over time. The identification of these attitudes allowed us to design, with the workshops' participants, a guiding framework to create monitoring programs (i.e. combinations of monitoring methods) adapted to a variety of uses and targeted services

ÉVALUATION DE LA SENSIBILITÉ AUX BIOAGRESSEURS DE 36 VARIÉTÉS DE POMMIERS DANS UN RÉSEAU DE PARCELLES BIOLOGIQUES À FAIBLES INTRANTS

Les bioagresseurs sont une des principales limites à la production de pomme dans les systèmes conduits en AB et à faibles niveaux d’intrants. Une des clefs du contrôle des bioagresseurs dans ces vergers est le choix des variétés (Trapman et Jansonius, 2008). La variabilité de l’expression de la sensibilité variétale peut être appréhendée grâce à un réseau multi-site pluri-annuel. Quatre parcelles de pommier biologique conduites de manière semi-extensive ont été plantées en 2002 afin d’identifier des variétés d’intérêts pour les systèmes à faible intrants. 36 variétés ont été suivies afin d’évaluer conjointement leur sensibilité à la tavelure, aux pucerons et à l’oïdium.La thématique de cette étude initiée en 2002 se trouve être au coeur des questionnements récents sur la réduction des intrants en arboriculture (programme ECOPHYTO 2018). Cette étude souligne (1) la spécificité des variétés intéressantes pour un site donné, (2) l’apparation dans certains cas de maladies considérées comme anecdoctiques, (3) l’intérêt de dispositifs multi-sites et d’observations pluriannuelles pour évaluer avec fiabilité la sensibilité aux bioagresseurs, (4) la méthodologie adaptée à cette problématique (méthode de notation, type de dispositif, etc)