Structure of some cyclohexyl compounds as related to their ability to stimulate plant growth

Aqueous solution, 10 mm, of cyclohexanecarboxylic, cyclohexylacetic, cyclohexylpropionic, cyclohexylbutyric acids (all components of naphthenic acid); cis-1,2-, and trans-1, 4-cyclohexyldicarboxylic acids; 3-cyclohexene-1-carboxylic and cyclohexylsulfamic acids; and cyclohexyl mercaptan were applied to 14-day-old bush bean plants, Phaseolus vulgaris L. cv. Top Crop. Only cyclohexanecarboxylic and cyclohexylacetic acid resulted in a statistically significant (P = 0.05) increase in pod production per plant in all experiments. The stimulation by the first four monocarboxylic acids decreased as the number of methylene groups in the side chain increased from 0 to 3. The effective compounds possessed an H-saturated 6-carbon ring with a single carboxyl group attached directly to the ring or separated from it by no more than one methylene group.