Effect of permanent ground cover on agronomic properties and soil fertility in an organic peach orchard

In conventional orchards, weeds on the raw are mainly controlled with chemical herbicides because of their efficiency, their low cost and ease of use. The most common method in organic orchard to eliminate weeds on the raw consists of tillage operations. However, some drawbacks of these mechanical methods have been demonstrated: (1) the energetic cost (non-renewable energy) is high, (2) this method is time-consuming, (3) tillage interferes with the development of superficial roots and can hurt the trunk, (4) the physical, chemical and biological properties of the soil can be disturb and (5) erosion and runoff potentially increase. Cover crops are interesting alternatives to manage ground cover but the effect on the agronomic properties and the soil fertility of these methods should be assessed. This study is included in the national program “Casdar SolAB” supported by the French Ministry of Agriculture. The effect of a White Clover crop versus tillage practice on the tree raw was assessed in an irrigated organic Peach orchard. White Clover was sowed in 2004. Soil parameters (water and nutrients availability, soil porosity, root density, earthworms density, soil profile) and agronomic parameters (yield, fruit quality, pests and diseases damages) were recorded since 2004. A 50% decrease of the organic fertilizer supply in the White Clover treatment has not affected yield and fruit quality from 2005 to 2009. It suggests this cover crop is well adapted to our pedoclimatic conditions without exerting a significant competitive effect. Root density is higher in the superficial layers of the soil in the White Clover treatment. Simplified Beerkan test used to assess soil porosity has also shown that soil porosity is higher in this treatment. No vole damage was observed in the plot

Effect of White clover (Trifolium repens cv. Huia) cover crop on agronomic properties and soil biology in an organic peach orchard

In orchards, cover crops are interesting alternative strategies to tillage or chemical herbicides for managing weeds in the tree row. However, little is known about the effect of cover crops on agronomic properties and soil biology in organic orchards. To fill this gap, the effects of two weed managements, a White clover cover crop (CC) versus classical tillage practice (T) on the tree row, were assessed in an irrigated organic Peach orchard. White clover was sown in 2004, 2006 and 2009 in the tree row and ploughed in 2006 and 2008. Root density, earthworm density, water infiltration rate, nitrogen content and water availability were measured in the soil, in the tree row. In 2009, peach root density observed in the superficial layers was higher in CC treatment. Sampling dates and treatment have a significant effect on total earthworm density with higher abundance observed in CC. However, no difference was observed between CC and T anecic earthworm groups known to make large and vertical burrows. Infiltration rate measured with the simplified Beerkan method was higher in CC treatment. This could be explained by the thick superficial root mat which was associated to a significant higher epigeic earthworm density in CC. Whereas nitrogen supplies were twice lower in CC treatment since 2005, soil nitrogen availability was equivalent in both treatments. These results demonstrate the agronomic interest of nitrogen-fixing plants used as a cover crop in organic peach orchards

Quelles alternatives au cuivre ? Bilan du projet européen CO-FREE

The project CO-FREE (2012-2016) aimed to develop strategies to replace/reduce copper use in organic, integrated and conventional farming. CO-FREE alternative test products (CTPs) were tested and integrated together with decision support systems, disease-tolerant varieties, and innovative breeding goals (ideotypes) into improved management strategies. CO-FREE focused on apple/apple scab (Venturia inaequalis), grape/downy mildew (Plasmopara viticola), and tomato and potato/late blight (Phytophthora infestans)

Apricots cultivars suited for organic production in the Mediterranean region (BIOFRUITNET Practice Abstract)

Adapted varieties make orchard management easier, less reliant on plant protection, and less risky from an economic point of view. Practical recommendation • The Mediterranean region covers a very large area in Europe. The list of cultivars presented below synthesises observations realised in the south of France (mild winter, hot and dry summer, average annual rainfall of about 800 mm). • In the context of climate change, some cultivars that were once well adapted could be someday less rec-ommendable. For example, for reasons of unsatisfied chilling needs. We recommend getting information on the chilling requirements of the variety before planting (e.g., from the nursery, other farmers or exper-imental stations). For specific information on blossom brown rot susceptibility. • The diversity of varieties planted on a farm improves the farm’s economic resilience

Propriétés radiatives des couronnes de Noyers (Juglans nigra x J. regia) et croissance des pousses annuelles - Influence de la géométrie du feuillage, de la position des pousses et de leur climat radiatif

Th-0602Modelling tree architectural development according to environmental factors is an emerging field ofresearch thanks to the development of adequate computational methods. However, modelling virtualplants is greatly constrained by the difficulty in collecting the architectural and geometric data of woodyarchitecture and foliage. Moreover, partial understanding of functional processes that drive shoot growthlimits the analysis and the modelling of the processes involved. Cross-fertilization of insights intoarchitectural and morphological variability of Walnut tree on the one hand, and into growth physiology onthe other hand, enables to better understand crown development. Thanks to 3-dimensional measurementsof topology and geometry made on 7 to 9 years-old Walnut trees, we have analysed the impact on lightinterception of variables required for virtual plant modelling that are tedious to measure and that renderextrapolation methods necessary. Secondly, we quantified the part of variance of growth variables whichcan be explained by radiation intercepted by comparison with other factors such as topological position.Our results point out the limitations of using allometric relationships and statistical laws for thereconstruction of 3D canopies. Leaf clumping inside the crown, including the clumping of leaflets at leafscale, strongly determines the radiative properties of reconstructed crowns. Thanks to an approach basedon correlations and statistics, an effect of light intercepted by mother shoots on the growth of daughtershoots was established. Strong correlations between shoot vigour (quantified by an index) and the lengthof the pathway between the collar and shoots on the one hand and shoot growth on the other handsuggest an effect of hydraulic architecture.La modélisation du développement architectural des arbres en réponse aux facteurs environnementaux est un thème de recherche en plein essor grâce au développement récent de méthodes informatiques adéquates. Cependant, l'utilisation de couronnes 3D est fortement contrainte par la difficulté à collecter les données architecturales et géométriques nécessaires à leur reconstruction. Par ailleurs, la compréhension partielle des processus fonctionnels contrôlant la croissance des pousses au sein des couronnes limite actuellement l'analyse et la modélisation des processus impliqués. La confrontation des connaissances acquises sur la variabilité architecturale et morphologique du Noyer d'une part, et celles acquises sur la physiologie de sa croissance d'autre part offre la possibilité de mieux comprendre le développement de la couronne. A partir de mesures et d'échantillonnage de la topologie et de la géométrie de Noyers hybrides âgés de 7 à 9 ans, nous avons analysé l'impact sur l'interception de la lumière de variables nécessaires à la reconstruction de plantes virtuelles mais dont la mesure nécessite un travail long et difficile qui rend indispensable l'utilisation de méthodes d'extrapolation. Puis, nous avons quantifié la part de variance des variables de croissance qui peut être attribuée à la lumière interceptée vis-à-vis d'autres facteurs tels que la position topologique. Nos résultats quantifient les biais introduit par l'utilisation de relations allométriques et de lois statistiques pour reconstruire des couronnes tridimensionnelles de différentes tailles. Nous avons montré que l'agrégation du feuillage au sein de la couronne, y compris à l'échelle des feuilles (composées de folioles), détermine fortement les propriétés radiatives des couronnes reconstruites. Grâce à une approche corrélative et statistique, un effet de la lumière interceptée par les pousses mères sur la croissance des pousses filles a été mis en évidence. Les fortes corrélations observées entre d'une part la vigueur des pousses (quantifiée par un indice) et la longueur du chemin entre le collet et les pousses et d'autre part leur croissance suggèrent un rôle de l'architecture hydrauliqu

Cover crops (living mulches) in the tree row of organic orchards: why and how? (BIOFRUITNET Practice Abstract)

After establishing living mulch, tree row maintenance is cheaper and, depending on the species, can provide different ecosystem services (e.g., nitrogen fixation), functional biodiversity (e.g., nectar source for pollinators, habitat for beneficials), soil conservation, etc... The cultivation of secondary cash crops as living mulch can be a source of additional income. Practical recommendation • Prepare the establishment of the living mulch with summer tillage, then prepare the seedbed in early autumn. • Prefer short, low-lying perennial species with high capacity of soil coverage in irrigated orchards. • For perennial species, sow or plant living mulches in autumn to favour their establishment. During the first season, one or two mowings and possibly manual weed control may be necessary. After establishment, if necessary, mow once a year to maintain a moderate plant height. • Among the perennial living mulching species adapted to orchards in different pedo-climatic conditions: yarrow (Achillea millefolium, Picture 1), wild strawberries (Fragaria vesca), peppermint (Mentha piperita), lady’s mantle (Alchemilla vulgaris, Picture 2), crawling thymes (Thymus spp.), mouse-ear hawkweed (Pilosella officinarum), caucasian crosswort (Phuopsis stylosa, Picture 3), creeping cinquefoil (Potentilla reptans) and white bedstraw (Galium album). • For rainfed orchards or those with a high risk of vole damage, favour the sandwich system (Tschabold, 2009) or the cultivation of annual species (vegetables, annual clover, etc.). • When selecting the species, favour local ecotypes better adapted to pedo-climatic conditions

Alternatives to copper-based treatments for the control of grapevine downy mildew (Plasmopara viticola): 5-year synthesis of trials in France and Italy

The objective of the UE-funded program REPCO (FP6) was to identify new alternatives to copper fungicides in organic farming. Two pathogens have been considered: grapevine downy mildew (Plasmopara viticola) and apple scab (Venturia inaequalis). Research on grapevine was carried out by GRAB (Avignon, France) and FEM-IASMA (San Michele all’Adige, Italy). Trials were carried out under natural conditions in order to test reduced doses of copper and copper-free alternatives. Five-year trials proved that copper is the best fungicide. However, the use of new low copper rate formulations and the association of copper-free alternatives with reduced doses of copper or with reduced number of copper applications (limited to the most susceptible grapevine growth stages) were able to control of downy mildew with a concomitant reduced impact to the environment. Among the tested products, Trichodex (Trichoderma harzianum T39), Mycosin (clay), Chitoplant (chitosan), Saponin (Yucca extract), and an experimental sage extract (Salvia officinalis) gave the best results. The level of plant protection was similar to copper (standard), but not significantly different from the untreated control. Efficacy was good under low or medium disease pressure, but decreased when the pressure increased. The trials carried out after REPCO project confirmed that blossom stage is the most risky period for downy mildew infection and that a reduction of the number of treatments, with consequent reduction of the yearly total amount of copper, is possible by applying treatments during this period. These results show that more research efforts are needed to substitute copper in organic grape growing, and at present the practical approach must focus on combining strategies (alternative products and reduced copper, understanding the most susceptible stages of the plant, applying disease forecasting models, etc.)

Quels besoins techniques en arboriculture biologique en Europe ? Exemple des ravageurs du pommier

Le projet européen BIOFRUITNET (2019-2022) a pour objectif d'identifier les réseaux de producteurs de fruits biologiques, rassembler les connaissances pratiques existantes et recenser les difficultés dans la production biologique de fruits à pépins, de fruits à noyau et d'agrumes en Europe. Afin de mieux connaître les besoins techniques et les pratiques concernant la production de pomme, poire, abricot, pêche, prune, cerise et orange en agriculture biologique, une enquête a été réalisé auprès de 149 agriculteurs et 100 conseillers techniques dans 26 pays. Le poster présente des résultats concernant la pomme

Fiche technique : Hoplocampe du pommier en AB

Le contrôle des ravageurs dits secondaires pré-occupe de plus en plus les arboriculteurs. La plus grande sélectivité des méthodes de protection phytosanitaire utilisées explique en partie l’augmentation de leur présence. Dans le contexte phytosanitaire actuel, il est primordial de caractériser les risques et d’identifier les solutions disponibles pour contrôler ces ravageurs. L’hoplocampe du pommier est un ravageur largement répandu en Europe et en Amérique du Nord. En verger de pommier conduit en AB, il peut entrainer de très fortes pertes de rende-ment préjudiciables économiquement. D’autres espèces d’hoplocampes s’attaquent à la poire (H. brevis) et à la prune (H. minuta et H. flava), elles ne sont pas traitées dans cette fiche

IS LEAF LITTER REMOVAL MORE EFFICIENT THAN LEAF LITTER SHREDDING TO CONTROL APPLE SCAB? A FIRST ANSWER IN A COMMERCIAL ORGANIC ORCHARD

In organic apple orchards, sanitation practices are a keystone of a sustainable scab management. Because the suppression of the inoculum by leaf litter removal could be a promising practice, we carried out an experiment to assess the interest of leaf removal versus leaf shredding on disease development and fruit damages. For one of the two cultivars studied, we showed that leaf litter removal can significantly decrease scab damages on fruit and leaf in comparison to leaf shredding