Competition-based Model of Pruning: Applications to Apple Trees

International audienceno abstrac

Effects of pruning on the apple tree: from tree architecture to modeling

International audienceArboricultural practices such as pruning, artificial bending or fruit thinning are crucial interventions in orchard management and are used for controlling tree size, penetration of light into the canopy and the equilibrium between vegetative and reproductive growth. The aim of this project is to explore the possibility of integrating such practices in a model of apple tree development. To this end we designed field experiments to study the effects of pruning (thinning or heading cuts) on two apple cultivars with contrasted architecture, ?Fuji? and ?Braeburn?. The results of these first experiments showed that the studied cultivars had significantly different reactions to pruning: ?Braeburn? trees were penalized more than ?Fuji? trees in terms of the total number of internodes despite the fact that a greater number of internodes had developed. Thinning cuts of laterals tended to be compensated by an increase in lateral branching. Results also indicated that trees which had been pruned tended to develop trunks with similar number of internodes than control trees (which were not pruned). These experiments constitute a first step for assessing the rules underlying tree responses to pruning, which will be further integrated in a model of growth

Delayed grape ripening by intermittent shading to counter global warming depends on carry-over effects and water deficit conditions

Grapevine phenology is continuously advancing due to global warming, exposing berry ripening to increasingly drier and hotter episodes that can dramatically affect yield and berry quality. This study aimed to analyse whether intermittent shading produced by panels placed over the plants can delay berry ripening to counter the impact of global warning on phenology. A two-year outdoor trial repeated on two batches of young potted grapevine (cv. Syrah) was conducted in Montpellier (South of France). Shading was created in a row using 2 m-wide horizontal panels placed 2.4 m above the ground. A moderate water deficit was also applied at the start of veraison to half the plants in both full sun (without panels) and shaded conditions to mimic usual field conditions. Variables related to budburst, flowering, veraison and sugar at harvest were analysed in all treatments. Although intermittent shading did not significantly modify air temperature within the canopy when cumulated over the growing season, the panels substantially delayed veraison by up to more than 30 days under well-watered conditions. The most marked phenological shifts were noted in the second year of treatment between flowering and veraison when carbon demand sharply increased during berry formation, suggesting there was a carry-over effect likely due to limited carbon assimilation. This was accompanied by sharp decreases in berry diameter and sugar content per berry at harvest. Higher berry growth and sugar loading were maintained when shading was combined with water deficit. However, the trigger effect of water deficit on veraison almost halved the phenological delay caused by the panels. Overall, a cooler period for ripening could be achieved with panels over the vines but at the expense of berry size and sugar amount in berries. It can be concluded that shading intensity and duration should be adapted to evaporative and soil water conditions to benefit from the phenological delay caused by panels, without altering production in the long term

How to understand the alternate production in apple tree ? A modeling approach of carbon and hormones fluxes

International audienc

Anomaly based Intrusion Detection for an Avionic Embedded System

International audienceThis paper firstly describes the challenges raised by the introduction of Intrusion Detection Systems (IDS) in avionic systems. In particular, we discuss some specific characteristics of such systems and the advantages and limitations of signature-based and anomaly-based techniques in an avionics context. Based on this analysis, a framework is proposed to integrate a Host-based Intrusion Detection System (HIDS) in the general Integrated Modular Avionics (IMA) development process, which fits avionic systems constraints. The proposed HIDS architecture is composed of three modules: anomaly detection, attack confirmation, and alert sending. To demonstrate the efficiency of this HIDS, an attack injection module has also been developed. The overall approach is implemented on an IMA platform running a cockpit display function, to be representative of embedded avionic systems

How young trees cope with the removal of whole or part of shoots: an analysis of local and distant responses to pruning in 1-year-old apple (Malus × domestica; Rosaceae) trees

Contact: [email protected], fax: +33 (0)4 6761 5596 Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699International audience• Premise of study: Manipulation of tree architecture by pruning provides an experimental context to analyze architectural plasticity resulting from competition between developing organs. The objective of this study was to quantify the effects of the removal of all or part of shoots through pruning on the redistribution of growth and flowering at spatial and temporal levels. • Methods: Two types of pruning cuts were applied: (1) heading cuts of either the main stem or laterals and (2) thinning cuts (i.e., complete removal) of laterals. These two types of cuts were applied in summer and winter on 1-yr-old cultivars of Fuji and Braeburn apple trees. Tree topology and geometry were described over 3 years, and responses were analyzed for both local and distant scales. • Results: Heading cuts induced quasi-deterministic local responses on pruned axes, whereas responses to thinning cuts were more variable. For the main stem and laterals, responses over greater spatial and temporal scales were highlighted with (1) stronger growth the year after summer pruning and (2) modification of branching and flowering along the unpruned parts after winter pruning. • Conclusions: Pruning typically induced growth redistribution toward traumatic reiterations and enhanced growth of the remaining unpruned axes with a concomitant decrease of flowering and cambial growth. Although results could be interpreted in relation to the root–shoot balance, tree responses appeared highly cultivar-specifi

Effects of pruning on the apple tree: from tree architecture to modeling

Arboricultural practices such as pruning, artificial bending or fruit thinning are crucial interventions in orchard management and are used for controlling tree size, penetration of light into the canopy and the equilibrium between vegetative and reproductive growth. The aim of this project is to explore the possibility of integrating such practices in a model of apple tree development. To this end we designed field experiments to study the effects of pruning (thinning or heading cuts) on two apple cultivars with contrasted architecture, 'Fuji' and 'Braeburn'. The results of these first experiments showed that the cultivars had significantly different reactions to pruning: 'Braeburn' trees showed a greater reduction in the total number of internodes compared to 'Fuji' trees, despite the fact that a greater number of internodes developed on 'Braeburn' trees. Thinning cuts of laterals tended to be compensated by an increase in lateral branching. Results also indicated that trees which had been pruned tended to develop trunks with similar number of internodes as control trees (which were not pruned). These experiments constitute a first step for assessing the rules underlying tree responses to pruning, which will be further integrated into a model of growth