Vol.8 (2018) No. 4-2 ISSN: 2088-5334 Dr.LADA: Diagnosing Black Pepper Pest and Diseases with Decision Tree Afzan Adam # , Kho Pei Ee * , Noraidah Sahari a , Angela Tida * , Chen Yi Shang * , Kevin Muyang Tawie * , Shafinah Kamarudin b , Hazura Mohamad a , # Center for Artificial Intelligence and Technology, Faculty of Information Sciences and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia. E-mail: afzan@ukm.edu.my * Research and Development Department, Malaysian Pepper Board, Lot 1115, Jalan Utama, Pending Industrial Area, 93916 Kuching, Sarawak. E-mail: khope@mpb.gov.my a Center for Software and Technology Management, Faculty of Information Sciences and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia. E-mail: nsa@ukm.edu.my * Faculty of Agriculture and Food Sciences, Universiti Putra Malaysia Bintulu Sarawak Campus, Nyabau Road, P.O.Box 396, 97008 Bintulu, Sarawak, Malaysia. Abstract— Malaysia has the distinction of being the world’s fifth largest pepper producer country whereby 98% of the country's annual production comes from the State of Sarawak. However, crop loss due to pest and disease incidence has been identified as one of the major pepper production constraints. Inefficient advisory mechanism and assistance from extension staff due to technical and logistic limitations have hindered the pest and disease diagnosis effort for pepper. Currently, extension staff from MPB will have to travel to the rural farms when contacted, or during their visits to advice or treat the plants. Therefore, by the Malaysian Pepper Board and Universiti Kebangsaan Malaysia has jointly developed Dr.LADA apps to diagnose six pests and ten diseases of pepper, which commonly found in Malaysia. This agriculture app can recommend appropriate management measures to solve the problems. This an interactive Android-based mobile app with an inference engine utilizes the decision tree with forward-backward chaining methods to trigger the correct disease or pest based on syndromes. The knowledge is interconnected symptoms extracted and validated by Malaysian Pepper Board experts. Dr.LADA is a native mobile app developed on a Java-based platform, which provides fast performance, a high degree of reliability and can be used without any internet connection. The app has been tested with 10 case studies carried out by the Malaysian Pepper Board and scored 97% of accuracy. Having Dr.LADA, the user can identify problems by answering a series of questions from symptoms shown by several plant parts. Therefore, the dependency of farmers on extension staff is reduced, and indirectly minimizing the extension activity costs. Keywords— agriculture app; diagnosing plant disease; decision tree. I. INTRODUCTION Black pepper (Piper nigrum L.) is the most widely used spice in the world and has gained global recognition as the “King of Spices” due to its monetary value and trade in the international spice market. It is one of the crucial commodities in Malaysia, known for its exquisite aroma and pungency. Malaysia is the world’s fifth largest pepper producer country whereby 98% of the country's annual production comes from the State of Sarawak [1]. Sarawak pepper is widely considered to be one of the best peppers in the world with geographical indication (GI) status recognition since 2003 [2]. According to the International Pepper Community [1], Malaysia pepper production rose to 29,245 tonnes with the total export of 12,199 tonnes which worth RM490.1 million in 2016. In addition, domestic consumption of pepper shot up by 11% to 13,500 tons in 2015, compared to 12,000 tons in 2014. The demands of pepper-based products are expected to increase in future. However, despite the quantity and commercial values, 1584