Biological data in sets of benzotriazole derivatives active as plant growth regulators

Forty-​six 1- or 2-​substituted benzotriazole derivs. were tested for their auxin-​like activity by the oat coleoptile elongation test and for their herbicidal activity as a function of their structure and of concn. At low and medium concns., these compds. behave as growth stimulators, while at highest concns. they are growth inhibitors. At concns. from 10-​6 to 10-​9 M, most of these compds. are more active than IAA. The presence of a functional group at C-​1 leads to an increase of activity. A few of these compds. showed a weak herbicidal activity on Yellow foxtail in a soil test, whereas practically no activity was obsd. with this plant in the foliar application. None of these compds. behaved like 2,​4-​D. Soil-​applied 2-​(benzotriazol-​2'-​yl)​propionamide was active (herbicide) on a no. of tested plants, but was inactive when applied foliarly.