Agricultural productivity is something on which economy highly depends. This is
the one of the reasons that disease detection in plants plays an important role in agriculture field, as having disease in plants are quite natural. If proper care is not taken in this area then it causes serious effects on plants and due to which respective product quality, quantity or productivity is affected. Detection of plant disease through some automatic technique is beneficial as it reduces a large work of monitoring in big farms of crops, and at very early stage itself it detects the diseases i.e. when they appear on plant leaves. This paper presents an algorithm for image processing technique which is used for automatic detection and classification of plant leaf diseases. It also covers survey on different diseases classification techniques that can be used for plant leaf disease detection and its sprayed the respective fertilizer on the leaves. The automatic mobile robots are used in this project.