Sugarcane being a long duration crop of 10-18 months faces many biotic and abiotic stresses which causes heavy losses in cane production and productivity. Timely and accurate diagnosis, of disorders that appear in crop due to these stresses, is required to reduce the losses. Paper illustrates CaneDES, an expert system to diagnose disorders in sugarcane caused by various biotic and abiotic stresses. It is a web based system available in both Hindi and English languages with remote accessibility to sugarcane farmers. A new classified knowledge representation technique has been adopted for the development of expert system, to manage the diagnostic knowledge efficiently. System was evaluated with the help of domain experts and extension personnel engaged in the services of sugarcane farmers. Evaluation was made in terms of time taken by extension personnel in diagnosis of disorder and confidence factor received from the system and results indicated high usability and efficiency of the system. System is of generic nature and can be used in other crop environment with changes in knowledge base.