Fuente: WIPO "stone fruits" Patent 542350 Disclosed is the use of compounds of formula (I), in which R1 is H or C1-C10 alkyl and R2 is C1-C10 alkyl or C3-C10 alkyl, or salts of these for reducing or preventing frost damage in pome and stone fruit and in citrus plants as the result of temperatures in the range of from -15 to 0 degrees C, wherein the compounds of the formula (I) or salts thereof are applied to the plants or their plant parts 36 hours to 20 days before a cold or frost spell.