Abstract: New 1,2,3-thiadiazole-5-yl-urea derivatives as plant growth regulating agents are provided, including processes for producing and using these compounds. The new 1,2,3-thiadiazole-5-yl-urea derivatives have the formula ##STR1## in which R.sub.1 is an aromatic hydrocarbon group which may be substituted with one or more members of the group consisting of C.sub.1 -C.sub.6 -alkyl, halogen, C.sub.1 -C.sub.6 -alkoxy, nitro and trifluoromethyl and R.sub.2 is hydrogen, a monovalent metal or its metal equivalent, a substituted or unsubstituted C.sub.1 -C.sub.6 -alkyl, a C.sub.3 -C.sub.6 -alkenyl or alkinyl, a substituted or unsubstituted aryl- C.sub.1 -C.sub.2 -alkyl or the group aryl-C.sub.1 -C.sub.2 -alkyl ##STR2## wherein R.sub.3 is hydrogen, a substituted or unsubstituted C.sub.1 -C.sub.10 -alkyl, C.sub.2 -C.sub.6 -alkenyl, a C.sub.2 -C.sub.6 -alkenyl, an aryl-C.sub.1 -C.sub.2 -alkyl, a C.sub.3 -C.sub.8 -cycloaliphatic hydrocarbon group which may be substituted with one or more C.sub.1 -C.sub.

Abstract: New 1,2,3-thiadiazole-5-yl-urea derivatives of the formula ##STR1## wherein R.sub.1 is hydrogen or a C.sub.1 -C.sub.4 alkyl group which may be interrupted by one or more sulfur or oxygen atoms, R.sub.2 is a C.sub.1 -C.sub.4 alkyl which may be interrupted by one or more sulfur or oxygen atoms, a cycloaliphatic hydrocarbon group which may be substituted by one or more alkyl groups, an aromatic hydrocarbon group which may be substituted by one or more members of the group consisting of alkyl, halogen, alkyl thio, alkoxy, trifluoromethyl and nitro, or a heterocyclic hydrocarbon group which may be substituted containing at least one nitrogen atom, R.sub.3 is hydrogen, a C.sub.1 -C.sub.10 alkyl group which may be substituted, a C.sub.2 -C.sub.8 alkenyl, an aryl-C.sub.1 -C.sub.2 alkyl, a C.sub.3 -C.sub.8 -cycloaliphatic hydrocarbon group which may be substituted with one or more C.sub.1 -C.sub.

Abstract: A composition for growth regulation of plants or for defoliating plants comprises in combination(a) at least one compound of the formula ##STR1## wherein R.sub.1 is hydrogen or alkyl of 1 to 3 carbon atoms and R.sub.2 is hydrogen or alkyl of 1 to 4 carbon atoms and R.sub.3 has the meaning defined in the specification and X is oxygen or sulfur and(b) at least one other plant growth regulating or defoliating agent which, in combination with the compound at (a) results in a synergistic effect in regard to the growth regulating and defoliant properties. The composition is particularly suited for the defoliation of cotton plants.

Abstract: The invention concerns an agent for defoliating plants and which contains as active substance 1,2,3-thiadiazolyl ureas.

Abstract: A composition for growth regulation of plants or for defoliating plants comprises in combination(a) at least one compound of the formula ##STR1## wherein R.sub.1 is hydrogen or alkyl of 1 to 3 carbon atoms and R.sub.2 is hydrogen or alkyl of 1 to 4 carbon atoms and R.sub.3 is alkyl of 1 to 4 carbon atoms, cycloalkyl of 5 to 8 carbon atoms, phenyl, halogenophenyl, methylphenyl, methoxyphenyl is nitrophenyl and X is oxygen or sulfur and(b) at least one other plant growth regulating or defoliating agent which, in combination with the compound at (a) results in a synergistic effect in regard to the growth regulating and defoliant properties. The composition is particularly suited for the defoliation of cotton plants.