 Crops are susceptible to various types of pathogenic microorganisms, which can cause significant economic loss to farmers. To combat this problem, several laboratory-based and indirect detection methods have been developed to identify and monitor plant diseases. These include PCR, IF, FISH, ELISA, FCM, GCMS, thermography, fluorescence imaging and hyperspectral techniques. Additionally, biosensor technology has emerged as a promising alternative for early detection of plant diseases. This article was authored by E. Fung and Ramaraja K. Ramasamy.