USE OF THE VIRTUAL TOOL LISTOMER FOR MEASURING LESION AREAS ON LEAVES

Abstract

Results are given from studies on using a computer-based program, called the virtual tool LISTOMER, which has been developed at the Siberian Physical-Technical Institute of Agrarian Problems, and intended for measuring total and affected areas of the plant leaves and identifying degrees of plant affections with diseases, pests, and other environmental factors. Thirty eight plant samples of Novosibirskaya 89 cultivar of spring common wheat, creeping wheat and awnless bromegrass with signs of brown rust, Septoria disease and powdery mildew were analyzed. The measuring procedure included scanning of a leaf with signs of a disease, producing a multicolored projection, followed by digital image processing with LISTOMER. The affected leaf area was singled out from the total area, and marked with color. Then, the quantitative characteristics of the affected area were calculated in both absolute and relative units. The standard scales and methods for estimating the intensity of lesions in per cents or scores were used. Brown rust was estimated on the Strakhov's scale, Septoria disease on the James scale, and powdery mildew on the scale developed at the N.I. Vavilov Research Institute of Plant Industry. The virtual tool LISTOMER is used to process statistical data and create experimental data bases. It allows determining total and affected leaf areas with the necessary accuracy, and recording degrees of plant affections to standardize quantifiable findings as to certain diseases.