| abstract |
A method and composition for the immunisation of healthy useful plants against plant diseases containing as active ingredients compounds of formula (I) in which: X is hydrogen, halogen, hydroxy, methyl, methoxy, HOOC or MOOC; Y is hydrogen, halogen, SO3H, SO3M, nitro, hydroxy or amino, M being the molar equivalent of an alkali metal or alkaline earth metal ion that is formed from a corresponding base or basic compound; and Z is cyano or -CO-A; A represents either -OH or -SH, the hydrogen atom of which may also be replaced by the molar equivalent of an inorganic or organic cationic residue, or wherein A represents any other organic residue which has a molecular weight of less than 900 and which may also contain one, or more than one, hetero atom, including the salts of the phytophysiologically tolerable 7-carboxylic acid or 7-thiocarboxylic acid with primary, secondary or tertiary amines or with inorganic bases. |