Abstract
Postharvest diseases are a common problem in the cultivation of apples. Since determining the exact disease is often difficult and time-consuming, an ontology-based decision support system is being developed to support this diagnosis process. In this paper a reference ontology is presented that captures the life-cycle of apples from the orchard to the storage phase. This ontology focuses mainly on postharvest diseases including their symptoms, characteristics, and other important factors. This reference model is represented using the ontology-driven conceptual modeling language OntoUML and it is then encoded as an OWL specification enriched with SWRL rules. The latter will then serve as a basis for supporting automated reasoning in the aforementioned decision support system.