▎ 摘　　要

NOVELTY - Use of a combination of graphene oxide and Bacillus siamensis for controlling Phytophthora in plants, is claimed. USE - The combination is useful in the preparation of a fungicidal agent or a drug for controlling Phytophthora, preferably Peronophthora litchii, Phytophthora nicotianae, Phytophthora sojae, Phytophthora melonis and Phytophthora capsici in plants (all claimed). ADVANTAGE - The combination has excellent inhibitory effect on various Phytophthora pathogens, exhibits synergistic effect, and increases crop yield. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a fungicidal agent or a drug for controlling Phytophthora in plants, which comprises the above-mentioned combination.