Growth-Controlling Effects of some Quaternary Ammonium Compounds on Various Species of Plants

Abstract

1. A quaternary ammonium compound, (4-hydroxy-5-isopropyl-2-methylphenyl)trimethylammonium chloride, 1-piperidine carboxylate, designated Amo-1618, was applied to soil in which bean seeds (Phaseolus vulgaris, variety Black Valentine) were planted. It was absorbed by the roots of seedlings and apparently translocated to the stems, leaves; and seeds. 2. Amo-1618 induced the plants to develop relatively short internodes, thick stems, and dark green leaves in comparison with untreated plants. Maturity was delayed. When the chemical was applied at rates of 1, 10, and 100 pounds per acre, the intensity of these responses was in proportion to the amount of chemical used. 3. The effect of Amo-1618 applied at the rates of 10 or 100 lb/A persisted in the soil apparently undiminished during a period of 3 years. At the rate of 1 pound per acre the effect of the chemical was diminished but was still apparent at the end of 3 years. 4. The effects of Amo-1618 absorbed from the soil and translocated to the seeds were evident in the following two successive generations. The intensity of effect decreased with each generation and was no longer apparent in the fourth generation. 5. Seven of forty-three species of crop plants tested were very responsive to the chemical when it was applied to the soil or directly to the plants by spraying or dipping. Six others showed a moderate response, and six additional ones were only slightly responsive. The remainder showed no visible response. 6. Seven new quaternary ammonium compounds were found to inhibit internodal elongation of bean plants; four of these were approximately as effective as Amo-1618. Of the compounds tested, seventy-four were supplied by the Chemical Biological Coordination Center and six by Sterling-Winthrop Research Institute, Rensselaer, New York.