Hanif, Alex Chandra2022-01-172022-01-172021-07wahyu sari yenihttps://repository.unri.ac.id/handle/123456789/10380Shallots are one of the main cooking seasonings originating from Iran, Pakistan, and the mountains to the north. Shallots contain vitamin C, potassium, fiber, folic acid \ calcium and iron. Shallots also contain natural growth regulators in the form of auksin and giberelin hormones. The handling of shallot plants always encounters obstacles, one of which is pest and disease attacks. Pest and disease attacks require quick and correct handling, because this can harm farmers of shallot crops and can have an influence on production of shallots. Therefore, an expert system was created to solve the problem using the web-based certainty Factor method. The results of certainty factor method was calculated in a form of the diagnosis of pests and diseases in onion plants, as well as the first solution to overcome the attacks. This expert system could help users to conduct early detection and know the temporary diagnosis of pests and diseases in onion plantsenCertainty FactorExpert SystemShallot PlantArticle