VIEW ARTICLE

Ecology and Epidemiology

Epidemiological Implications of the Spectrum of Resistance to Rice Blast. S. W. Ahn, Former research fellow, International Rice Research Institute, Los Baños, Laguna, Philippines, Present address: CIAT, Apartado Aereo 67-13, Cali, Colombia; S. H. Ou, former principal plant pathologist, International Rice Research Institute, Los Baños, Laguna, Philippines, Present address: Taiwan Agricultural Research Institute, Wu-feng, Taichung, Taiwan, Republic of China. Phytopathology 72:282-284. Accepted for publication 29 May 1981. Copyright 1982 The American Phytopathological Society. DOI: 10.1094/Phyto-72-282.

The infection efficiency and the infection rate of the spore population of Pyricularia oryzae was lower if the percentage of races to which each cultivar was resistant was high. It appears that cultivars with resistance to a high percentage of the races of the pathogen behaved as expected for “horizontal” or “general” resistance.