Agriculture produce especially sugarcane crop is no exception to diseases as compared to the other crops. Sugarcane diseases can be mitigated more successfully if they are identified properly and in the early stages of the diseases. Disease prone sugarcane crop directly affects the production quality and quantity. Sugarcane infections are a cause of worry for the farmers because they can wipe out the entire crop field, causing financial loss. Researchers are working on applying Artificial Intelligence (AI) techniques, like Machine Learning (ML) and Deep Learning (DL), to analyse the agricultural data (yield prediction, selling price forecasting, climate, and soil quality etc.) and prevent crop damage due to various reasons, diseases being one of them. Sugarcane producing farmers are required to be enriched with real-time data analysis using various computational techniques along with managing huge datasets. Deep neural network which includes Convolutional Neural Network (CNN) is a modern technique for agricultural disease detection. Hence, this paper presents the feasibility study and the effectiveness of DL based CNN algorithm in the disease detection of crops with special reference to selective four diseases of sugarcane crop in India. The study was prompted by the rapid evolution of sugarcane disease classes and farmers' lack of disease diagnostic and recognition skills. To solve this challenge, deep learning and computer vision are adopted. By categorizing sugarcane images into two groups: healthy and unhealthy/diseased (with disease type), the trained model is able to fulfill its goal. Using a simple CNN with four discrete classes, the analysis shows an accuracy of 98.69% for sugarcane disease detection. Further to guide the farmers, a web-based application is developed for sugarcane crop disease detection and implemented to fetch and monitor the data about the diseases. The paper also puts forth a few future research areas such as: (i) the user can enter the feedback which can be tuned with the model for accurately predicting the sugarcane crop diseases and dynamic database update; (ii) the effect of disease detection can be combined with agricultural productivity enhancement and price forecasting using AI tools and techniques, thereby aiding the farmers in effective decision making.