# An Ontology-Based Expert System for Rice Disease Identification and Control Recommendation
## 2 Related Works  
### Existing Ontologies and Vocabularies  
Table 1 summarizes and compares existing ontologies and vocabularies in the agriculture domain, with respect to their main focus and covered knowledge. AGROVOC [1] is a well-known vocabulary, covering many areas, such as food, nutrition, agriculture, fisheries, forestry, and the environment. Despite its huge size, the presented vocabulary is not applicable for rice disease identification and control recommendation due to the lack of specific rice plant axioms. Agriculture Activity Ontology (AAO) [2] is a part of the Common Agricultural Vocabulary (CAVOC). It was developed as a common vocabulary to support cooperation between different farm management systems. It defines farm activity expressions based on description logics, with eight kinds of essential attributes, e.g., purposes, actions, equipment, and crop names. The National Agricultural Library Thesaurus (NALT) ([[https://agclass.nal.usda.gov](https://agclass.nal.usda.gov)]([https://agclass.nal.usda.gov](https://agclass.nal.usda.gov)), accessed on 1 November 2021) is an agricultural vocabulary and glossary in English and Spanish. It covers 17 subject categories, such as food, animals, biological, farms, and insects. Phenotype and Trait Ontology (PATO) ([[https://github.com/pato-ontology/pato](https://github.com/pato-ontology/pato)]([https://github.com/pato-ontology/pato](https://github.com/pato-ontology/pato)), accessed on 1 November 2021) [3] provides definitions of phenotypic qualities (properties and attributes) that can be used to define phenotypes across species' domains, such as color (e.g., red, yellow), abnormal positions, temperatures (e.g., high, low), and symptoms (e.g., swelling) [4]. Planteome ([[https://planteome.org](https://planteome.org)]([https://planteome.org](https://planteome.org)), accessed on 1 November 2021) [8] provides a suite of reference ontologies for plants, such as Plant Trait Ontology (TO) ([[https://browser.planteome.org/amigo](https://browser.planteome.org/amigo)]([https://browser.planteome.org/amigo](https://browser.planteome.org/amigo)), accessed on 1 November 2021) [5; 6], accessed on 1 November 2021, Plant Ontology (PO) ([[https://browser.planteome.org/amigo](https://browser.planteome.org/amigo)]([https://browser.planteome.org/amigo](https://browser.planteome.org/amigo)), accessed on 1 November 2021) [7; 8; 9], and others. TO provides nine broad categories of plant traits, in which each category consists of measurable characteristics of plants. Planteome develops PO to model plant-related knowledge. Thus, PO describes anatomical structures and growth stages in the plant bodies (e.g., roots, stems, leaves, fruits, and seeds)  
Several rice plant knowledge-bases were developed using the OWL, RDF, and OBO formats. For example, the Crop Ontology Rice Trait Ontology (CO_320) ([[https://cropontology.org/term/CO_320:ROOT](https://cropontology.org/term/CO_320:ROOT)]([https://cropontology.org/term/CO_320:ROOT](https://cropontology.org/term/CO_320:ROOT)), accessed on 1 November 2021) [10] is a part of Crop Ontology (CO) ([[https://cropontology.org/](https://cropontology.org/)]([https://cropontology.org/](https://cropontology.org/)), accessed on 1 November 2021) [17; 16], providing validated trait names as well as the terminology of phenotypic data of rice plants. Plant Disease Ontology (PDO) ([[https://github.com/Planteome/plant-disease-ontology](https://github.com/Planteome/plant-disease-ontology)]([https://github.com/Planteome/plant-disease-ontology](https://github.com/Planteome/plant-disease-ontology)), [[http://wiki.plantontology.org/index.php/Plant_Disease_Ontology_](http://wiki.plantontology.org/index.php/Plant_Disease_Ontology_)]([http://wiki.plantontology.org/index.php/Plant_Disease_Ontology_](http://wiki.plantontology.org/index.php/Plant_Disease_Ontology_))(PDO), accessed on 1 November 2021) [11] provides a list of maize, wheat, and rice diseases, structurally classified into three main categories, i.e., bacteria, fungi, and viruses.