India is an agricultural country, wherein about 70% of the population depends on agriculture. Today, in agricultural plant disease is the significant concern as it reduces the production and quality of food. Hence there is a need to detect the plant diseases at the early stage. Detection of disease in the Banana tall plant is a major challenge in the field of agriculture. Banana leaf and fruit are highly affected by a disease. Hence we are going to detect the disease at the initial stage by using image processing and to classify the disease by using ANN. The methodology involves image acquisition, image pre-processing, image segmentation, feature extraction and detection and the classification of diseases. Results were obtained on these images by experimental simulations in MATLAB.