Worldwide, crop diseases are a major problem for producers with significant losses incurred. It has been estimated that an average of 20 – 30% of crop yield is lost annually from the field, even in crops where pesticides and cultivars with improved genetic resistance to pests and diseases are used. These losses can be greatly reduced by disease management practices steered by accurate and early diagnoses of pathogen presence. Unfortunately, methods commonly adopted for the isolation and diagnosis of many pathogens are slow and often deployed after disease symptoms are observed. For effective control and prevention of polycyclic disease epidemics early diagnosis of disease is essential to prevent spread.