The invention discloses 2-oxo- and 2-thioxo-1,3-dithiol compounds of the formula I below which have an advantageous action on plant metabolism. They selectively promote the formation of separation tissue on fruit and leaves and are suitable for facilitating the harvesting of olives and citrus fruit. The compounds have the formula <IMAGE> (I) wherein R1 is C1-C8alkyl optionally interrupted by one or more oxygen atoms or substituted by halogen or substituted or unsubstituted phenyl or phenoxy, unsubstituted or halogen-substituted C3-C8alkenyl, C3-C8alkynyl, C3-C6cycloalkyl, or substituted or unsubstituted phenyl, R2 is a hydrogen, methyl, C1-C8alkoxycarbonyl or substituted or unsubstituted phenyl, and X is oxygen or sulfur.
