Abstract: Plant growth regulant effects, such as dwarfing, cessation of terminal growth, increased flower set, increased fruit and pod set, fruiting body abortion, twisting and epinastic responses, etc., may be accomplished on crops such as soybeans, cotton, etc., by application of certain 2-(1,3,4-oxadiazol-2-yl) or 2-(2-oxazolyl) or 2-(1,3,4-thiadiazol-2-yl)benzoic acids, salts and esters, having the formula ##STR1## where X is nitrogen or C-R" (R" being hydrogen or methyl), Z is oxygen or sulfur when X is nitrogen, Z is oxygen when X is C-R", R is phenyl or various substituents, and R' is hydrogen or various substituents. An example is 2-(5-phenyl-1,3,4-oxadiazol-2-yl) benzoic acid. The compounds where X is nitrogen and Z is sulfur are new compounds, e.g., 2-(5-phenyl-1,3,4-thiadiazol-2-yl)benzoic acid.

Abstract: 2-Thio, 2-sulfinyl and 2-sulfonyl pyridine N-oxides of the formula ##STR1## are useful for regulating the natural growth or development of plants. E.g., the compound wherein n = 1, R.sub.1 = methyl and R.sub.2 = 2,3,4-trimethylphenyl retards cotton and increases root growth of turf.

Abstract: 2-Thio, 2-sulfinyl and 2-sulfonyl pyridine N-oxides of the formula ##STR1## ARE USEFUL FOR REGULATING THE NATURAL GROWTH OR DEVELOPMENT OF PLANTS. E.g., the compound wherein n = 1, R.sub.1 = methyl and R.sub.2 = 2,3,4-trimethylphenyl retards cotton and increases root growth of turf.

Abstract: Plant growth regulant effects, such as dwarfing, cessation of terminal growth, increased flower set, increased fruit and pod set, fruiting body abortion, twisting and epinastic responses, etc., may be accomplished on crops such as soybeans, cotton, etc., by application of certain 2-(1,3,4-oxadiazol-2-yl) or 2-(2-oxazolyl) or 2-(1,3,4-thiadiazol-2-yl)benzoic acids, salts and esters, having the formula ##STR1## where X is nitrogen or C--R" (R" being hydrogen or methyl), Z is oxygen or sulfur when X is nitrogen, Z is oxygen and when X is C--R", R is phenyl or various substituents, and R' is hydrogen or various substituents. An example is 2-(5-phenyl-1,3,4-oxadiazol-2-yl)benzoic acid. The compounds where X is nitrogen and Z is sulfur are new compounds, e.g., 2-(5-phenyl-1,3,4-thiadiazol-2-yl)benzoic acid.

Abstract: New 2-(1,3,4-oxadiazole-2-yl) benzoic acids and salts and esters thereof, as well as certain 2-(2-oxazolyl) benzoic acids, salts and esters, having the formula: ##SPC1##Where X is nitrogen or C-R" (R" being hydrogen or methyl), R is phenyl or various substituents, and R' and the Y's are hydrogen or various substituents, are effective preemergence or postemergence herbicides, on various crops. The chemicals act selectively and are useful against purple nutsedge and in cranberry. Oxadiazoles of the invention may be made by reacting a benzhydrazide with phthalic anhydride to form a hydrazide which is cyclized by removal of the elements of water, using as a catalyst fuming sulfuric acid or dimethylformamide-sulfur trioxide complex.

Abstract: Plant growth regulant effects, such as dwarfing, cessation of terminal growth, increased flower set, increased fruit and pod set, fruiting body abortion, twisting and epinastic responses, etc., may be accomplished on crops such as soybeans, cotton, etc., by application of certain 2-(1,3,4-oxadiazol-2-yl) or 2-(2-oxazolyl) or 2-(1,3,4-thiadiazol-2-yl)benzoic acids, salts and esters, having the formula ##SPC1##Where X is nitrogen or C--R" (R" being hydrogen or methyl), Z is oxygen or sulfur when X is nitrogen, Z is oxygen when X is C--R", R is phenyl or various substituents, and R' is hydrogen or various substituents. An example is 2-(5-phenyl-1,3,4-oxadiazol-2-yl)benzoic acid. The compounds where X is nitrogen and Z is sulfur are new compounds, e.g., 2-(5-phenyl-1,3,4-thiadiazol-2-yl)benzoic acid.