Fecha de publicación: -- Fuente: WIPO "tomato" It is provided a method of detecting a pathogen in a plant, such HLVd in cannabis plants, comprising the steps of collecting a sample of the plant, contacting the sample with a colorant producing a colored mix, contacting a sample of the colored mix with an amplification buffer, the amplification buffer comprising a primer mix, a polymerase, NTPs or dNTPS. and determining the presence of the pathogen by observing a change of color in the colored mix, wherein the colorant changing color resulting from a change in pH when primers from the primer mix form primer dimers or multimers leading to a change in pH in the presence of pathogen nucleic acid.