Substituted thiosemicarbazides, their manufacture and use as plant growth regulants

A method of regulating the growth of plants comprising applying to the plants a growth-regulating amount of a compound of the formula ##STR39## wherein R is ##STR40## R.sup.1 is --OH, --NR'R", C.sub.1 -C.sub.4 alkyl or hydrogen;

• each of R' and R" independently is hydrogen or C.sub.1 -C.sub.10 alkyl C.sub.3 -C.sub.7 alkoxyalkyl or alkoxyalkoxyalkyl, C.sub.3 -C.sub.6 cycloalkyl, phenyl C.sub.1 -C.sub.2 alkyl where the phenyl group is optionally monosubstituted by fluoro or methoxy, or R' and R" taken together with the nitrogen atom to which they are attached form a pyrrolidino, piperidino or morpholino ring;
• m is 0,
• R.sup.3 is hydrogen or C.sub.1 -C.sub.4 alkyl
• R.sup.4 is hydrogen
• Ar is naphthyl, or a group having one of the following formulae:
• ##STR41## each R.sup.5 independently is C.sub.1 -C.sub.4 alkyl, chloro, bromo, fluoro, nitro, C.sub.1 -C.sub.3 alkoxy or C.sub.1 -C.sub.3 alkylthio, provided that both ortho positions are not substituted by alkyl;
• R.sup.6 is carbethoxy, phenoxy, benzyloxy, phenyl or dimethylamino;
• n is 0, 1, 2 or 3;
• q is 0 or 1;
• the sum of n plus q does not exceed 3;
• and p is 0 or 1;
• or an agriculturally-acceptable salt or ester thereof.

A method of regulating the growth of plants comprising applying to the plants a growth-regulating amount of a compound of the formula ##STR42## wherein R is ##STR43## m is 0, R.sup.3 is hydrogen or methyl,

• R.sup.4 is hydrogen
• Ar is ##STR44## each R.sup.5 independently is C.sub.1 -C.sub.4 alkyl, chloro, bromo, fluoro, nitro, C.sub.1 -C.sub.3 alkoxy or C.sub.1 -C.sub.3 alkylthio, provided that both ortho positions are not substituted by alkyl;
• R.sup.6 is carbethoxy, phenoxy, benzyloxy, phenyl or dimethylamino;
• n is 0 or 1 and
• q is 0,
• or an agriculturally-acceptable salt or ester thereof.

A method of regulating the growth of plants comprising applying to the plants a growth-regulating amount of a compound of the formula ##STR45## wherein R is ##STR46## R.sup.1 is --OH, m is 0,

• R.sup.3 is methyl,
• R.sup.4 is hydrogen,
• Ar is ##STR47## n is 0 and q is 0,
• or an agriculturally-acceptable salt or ester thereof.

A method of increasing the set of fruit on crop plants comprising applying to the plants an effective amount of a compound of the formula ##STR54## wherein R is ##STR55## R.sup.1 is --OH, --NR'R", C.sub.1 -C.sub.4 alkyl or hydrogen;

• Q is H or C.sub.1 -C.sub.4 straight chain alkyl;
• each of R' and R" independently is hydrogen or C.sub.1 -C.sub.10 alkyl, C.sub.3 -C.sub.7 alkoxyalkyl or alkoxyalkoxyalkyl, C.sub.3 -C.sub.6 cycloalkyl, phenyl C.sub.1 -C.sub.2 alkyl where the phenyl group is optionally monosubstituted by fluoro or methoxy, or R' and R" taken together with the nitrogen atom to which they are attached form a pyrrolidino, piperidino or morpholino ring;
• each R.sup.2 independently is chloro, fluoro, bromo, methyl, nitro or trifluoromethyl;
• m is 0, 1 or 2;
• R.sup.3 is hydrogen, C.sub.1 -C.sub.4 alkyl, C.sub.3 -C.sub.4 alkenyl containing no .alpha.,.beta.-unsaturation, 2-hydroxy ethyl, phenyl or benzyl;
• R.sup.4 is hydrogen or C.sub.1 -C.sub.3 alkyl;
• Ar is naphthyl, anthranyl, phenanthryl or a group having one of the following formulae:
• ##STR56## each R.sup.5 independently is C.sub.1 -C.sub.4 alkyl, chloro, bromo, fluoro, nitro, C.sub.1 -C.sub.3 alkoxy or C.sub.1 -C.sub.3 alkylthio, provided that both ortho positions are not substituted by alkyl;
• R.sup.6 is carbethoxy, phenoxy, benzyloxy, phenyl or dimethylamino;
• n is 0, 1, 2 or 3;
• q is 0 or 1;
• the sum of n plus q does not exceed 3;
• and
• p is 0 or 1;
• or an agriculturally-acceptable salt or ester thereof.

A method of increasing the set of fruit on crop plants comprising applying to the plants an effective amount of a compound of the formula ##STR57## wherein R is ##STR58## R.sup.1 is --OH, --NR'R", C.sub.1 -C.sub.4 alkyl or hydrogen;

• m is 0,
• R.sup.3 is hydrogen or C.sub.1 -C.sub.4 alkyl,
• R.sup.4 is hydrogen
• Ar is naphthyl, or a group having one of the following formulae:
• ##STR59## each R.sup.5 independently is C.sub.1 -C.sub.4 alkyl, chloro, bromo, fluoro, nitro, C.sub.1 -C.sub.3 alkoxy or C.sub.1 -C.sub.3 alkylthio, provided that both ortho positions are not substituted by alkyl;
• R.sup.6 is carbethoxy, phenoxy, benzyloxy, phenyl or dimethylamino;
• n is 0, 1, 2 or 3;
• q is 0 or 1;
• the sum of n plus q does not exceed 3;
• and
• p is 0 or 1;
• or an agriculturally-acceptable salt or ester thereof.