The present invention addresses the problem of providing an agricultural and horticultural germicide composition that exhibits an excellent control effect against plant diseases even in a small amount, and that is not a cause for concern regarding phytotoxicity with respect to useful plants. This agricultural and horticultural germicide composition includes: at least one compound A selected from the group consisting of compounds and the like represented by formula (1) {In formula (1): each X is independently a halogeno group or a C
