n-Triacontanol is a plant growth regulator originally isolated from alfalfa that has plant growth-stimulating and antioxidant activities.^1,2,3 It increases the dry weight of barley, corn, and tomato seedlings in greenhouse pot tests when applied topically at concentrations of 0.001 and 0.01 mg/L.¹ n-Triacontanol (1 µM) increases the photosynthetic rate in isolated pea protoplasts and pea seedlings.² It increases photosynthesis in pea protoplasts when used at a concentration of 1.56 µM. n-Triacontanol is also an inhibitor of 1-lipoxygenase (1-LO; Ki = 5 µM for the soybean enzyme) and decreases the levels of thiobarbituric acid reactive substances (TBARS), a marker for lipid peroxidation, in isolated chloroplasts from spinach leaves when used at a concentration of 120 nM.³ Formulations containing n-triacontanol have been used as plant growth regulators in agriculture.