Plants of bush bean, Phaseolus vulgaris L., were sprayed with solutions of sodium and potassium naphthenates in the concentrations 50, 100, 500, 1000, 2500, and 5000 ppm. The treatments were applied when the plants were two, three, five, and seven weeks old, and also at various combinations of these times. A single application of 5000 ppm naphthenate to two-week-old plants, and multiple applications which included treatment of plants at this primary leaf stage of growth, resulted in the greatest stimulation to juvenile growth, measured as fresh and dry weights of stems and leaves, four weeks after treatment. This treatment also resulted in the greatest increase in green pod yield (20%), seven weeks after spraying, and in ripe seed production (8%). No advantage resulted from multiple treatments in these instances.