ABSTRACT
Survey on the plant diseases is one of the important aspects in the disease management. Pest and disease surveillance programmes are in existence and the Indian Government has set of staff for disease surveillance. Among different states, Tamil Nadu has an organized pest and disease surveillance programmes which is functioning effectively throughout the state. The pest/ disease surveillance report should accompany the details on the daily weather data viz., minimum temperature, maximum temperature, relative humidity, rainy days, rainfall, wind velocity, etc. There are two types of survey. They are fixed plot survey and roving survey. Assessment of amount of a disease on a plant is essentially required to study quantitative epidemiology. Assessment is essential for the fungicide manufacturing firms, plant breeders and academicians for studying treatment efficacies and evaluation of resistant varieties. Assessment of a specific disease in a crop over several years provides factors governing its incidence and severity.
