INFLUENCE OF ACETIC-ACID ON REGROWTH OF DIOECIOUS HYDRILLA FROM ROOT CROWNS

Sediments may contain numerous compounds resulting from anaerobic degr adation of organic matter, including acetic acid which has been shown to reduce viability of vegetative propagules. Root crowns of hydrilla (Hydrilla verticillata (L.f.) Royle) were exposed to acetic acid conce ntrations of 0, 17, 44, 87, 174, and 348 mmol/L for 24 h. Acetic acid concentrations which produced a 50% reduction in growth (measured by d ry weight, shoot length, or number of new shoots) ranged from 9 to 26 mmol/L. It may be possible to use a dilute acetic acid solutions to tr eat exposed hydrilla plants during drawdown.