Architecture and fruiting of the apple tree in agroforestry systems – coupling architectural development, flowering, fruiting and sap flow
Agriculture has evolved tremendously to increase productivity and quality in the past decades. It was often achieved by plant breeding and at the cost of an increasing dependence on external inputs, i.e., water, fertilizers and pesticides. Apple orchards are no exception. Society is now questioning the means used because of the generated environmental pollution and health issues. Different solutions have been considered to reduce this dependence including redesigning agrosystems to rely on ecosystem-based services. Multispecies AgroForestry Systems (AFS), such as the association of tailored perennial and annual crops and possibly animals in one field, could increase income sources, enhance pest control, improve resource use efficiency and buffer extreme climatic events. Since 2016, an AFS located in the south-east of France, characterized by a Mediterranean climate, has been designed to achieve these objectives. It includes three strata: walnuts grown for timber at the higher stratum, apple trees at the intermediate stratum, and a pulse crop at the lowest stratum. This AFS presents a good opportunity to study the effect of such agrosystems on apple tree architecture, physiology and production. In addition to the aforementioned interests, these systems would be potentially interesting in the Mediterranean area to limit the harmful effects of recurrent excessive summer radiation (light and temperature). The aim of my research is to acquire a detailed knowledge of the tree’s architectural development, its flowering, the quality of its fruiting and the daily and annual dynamics of sap flow along a competition gradient induced by the walnut trees. Using a functional-structural plant models approach, data collected during the third and fourth years of tree growth are analysed based on mutli-scale tree graph, to decipher whether and how the apple tree’s responses to its environment significantly affect its architecture and fruit production over consecutive years. Apart from acquisition of knowledge, a potential output of my PhD work will be the proposal of assembling rules, at spatial and temporal levels, to optimize the design of such apple tree-based AFS.
Benjamin Pitchers won an ISHS Young Minds Award for the best oral presentation at the International Symposium on Evaluation of Cultivars, Rootstocks and Management Systems for Sustainable Production of Deciduous Fruit Crops at the IHC2018 in Turkey, in August 2018.
Benjamin Pitchers, INRA - Centre Occitanie Montpellier - UMR System 1230, 2 place Pierre Viala - Bat 27, 34 060 Montpellier, France, e-mail: firstname.lastname@example.org
The article is available in Chronica Horticulturae