Evaluation of Severity of Turfgrass Patch Disease Development by Image Analysis

Abstract

Severity of the patch diseases of turfgrass was evaluated objectively by image analysis. An area of large patch disease was phtoguraphed on a color film. The color image was incoporated into a personal computer. Red color image which is one of the components of a color image was effective to distinguish the brown-colored patch area from the greencolored healthy area. Analysis of the red color intensity within tha patch area was consistent with disease severity of the area which was assessed by naked eyes. This analytical method was applicable to evaluate the control effects of a fungicide to large patch disease of zoysiagrass and also to compare disease resistance of bentgrass cultivars.