Tree Vigour in Apple Production: Impact of Replant Disease and Mitigation Strategies

Cultivating apples on sites previously used for cultivation of apples leads to suppression of vegetative performance of apple trees and losses in fruit yields. This replant effect is attributed to an apple related form of soil fertility loss named ‘soil fatigue’ and ‘Apple Replant Disease’ (ARD). Replant disease strongly affects profitability of apple production in nurseries specialised in fruit trees, as well as on fruit orchards. Recent studies focus on causally linked agents of the replant disease and quantification of its impact on apple tree. Handling replant disease, however, is challenged by the lack of knowledge of causal agents of the soil-borne disease and interaction between replant soil and tree vigour. The main objective of this study was to contribute to an agro-ecological estimation and mitigation of replant impact by soil management. To this end, three field studies were performed in apple fruit production on replant soil and in direct vicinity to no-replant soil. In-field studies were accompanied by pot trials for estimating effects of soil treatment by two management strategies.