Systemic herbicides and methods of use

A herbicidal composition comprising a herbicidally effective amount of a combination of a systemic herbicide stable in said composition and a monoadduct of sulfuric acid and one or more members selected from the group consisting of biuret, triuret, formamide, thioformamide, dimethylformamide, thiourea, mono-N-allyl thioformamide, 1-(4-aminobenzenesulfonyl)-2-thiourea, 1-benzoylurea, 1,3-bis(2-ethoxyphenyl) carbamide, 1-(2-bromo-3-methylbutanoyl) carbamide, 1-(4-bromophenyl) carbamide, 1,3-diacetyl carbamide, 1-ethyl-2-selenourea and N,N-methylphenyl formamide.

A method for controlling the growth of vegetation which comprises contacting said vegetation with a herbicidally effective amount of a composition comprising a systemic herbicide stable in said composition and a monoadduct of sulfuric acid with a compound, other than urea, having the formula:

• ##STR10## wherein X is selected from the group consisting of oxygen and sulfur;
• R.sub.1 is hydrogen;
• and each of R.sub.2 and R.sup.3 is independently selected from the group consisting of hydrogen, C.sub.3 to C.sub.10 substituted or unsubstituted cyclic radicals, C.sub.1 to C.sub.10 substituted or unsubstituted acyclic radicals, C.sub.3 to C.sub.10 substituted or unsubstituted cyclic radicals containing one or more heteroatoms, and C.sub.1 to C.sub.10 substituted or unsubstituted acyclic radicals containing one or more heteroatoms wherein (a) said substituents are selected from the group consisting of thiol, hydroxy, nitro, amino, nitrile, amide, ester, and halogen groups, and (b) said heteroatoms are selected from the group consisting of sulfur, nitrogen, oxygen, and phosphorus atoms.