Herbicides for injection into flowing water: acrolein and endothal‐amine

Abstract

Summary Treatment of flowing water by injection with acrolein is widely used in Australia and elsewhere for control of submerged aquatic plants. However, since acrolein has several disadvantages the amine salt of endothal has been assessed as an alternative for control of Elodea canadensis Rich., the most important species in blocking irrigation flow in south‐eastern Australia. Using an exposure time of 3 h in a static assay in the field the standard treatment with acrolein, nominally 15 ppm, was far more effective than endothal at about 5 ppm, similar results being obtained in spring, mid‐ and late summer. In a test over a range of concentrations in mid‐summer, acrolein gave 80% reduction of biomass at 2·8 ppm but endothal did not give this level of control even when more than 100 ppm was used. Endothal was also relatively ineffective when injected into flowing water. Measurements of net photosynthesis and lethality suggest that the order of tolerance to acrolein is Potamogeton tricarinatus F. Muell & A. Benn., > E. canadensis ≥ Vallisneria gigantea Graebner, so that routine treatments with acrolein may contribute directly to changes in relative species dominance. Use of sublethal concentrations of acrolein stimulated the growth of E. canadensis relative to untreated controls, perhaps by reducing the competition of aufwuchs.

Factors affecting the efficacy of acrolein in irrigation channels in southern Argentina

“…Within the range registered in the canals, water turbidity was not an important factor in the dissipation process. A satisfactory aquatic weed control was reported in muddy waters by Bowmer and Smith (1984). Other results (Nordone et al.…”

“…Moreover, the amounts of weed cover or volume of herbicide applied have no significance in the dissipation of acrolein. Other studies have reported greater herbicidal losses as a result of short‐time treatments (Bowmer & Smith, 1984).…”

“…Dissipation was assessed by measuring the variations of the chemical concentration in the water at several locations downstream from the site of injection, as well as by the calculation of the constant rate of dissipation ( K ) in litres per hour. The dissipation constant ( K ) for each treatment was assessed using the following equation: where U is the average water velocity, C a and C b are the maximum concentration between two sites (a and b) in mg L −1 , and X a and X b are the distance from the application point (Bowmer & Sainty, 1977; Bowmer & Smith, 1984).…”

Review of USACE-Generated Efficacy and Dissipation Data for the Aquatic Herbicide Formulations Aquathol(R) and Hydrothol(R). Aquatic Plant Control Research Program

“…Where water was hard (alkaline), an increase in concentration and exposure time to 4-mg ae L" for 5 hr was required for equally satisfactory weed control. However, only variable plant control was reported in several situations where herbicide concentration dissipated to low levels soon after application (Price 1969;Bowmer et al 1979;Bowmer and Smith 1984). Once concentration and exposure time relationships for endothall were well-defined (Netherland, Green, and Getsinger 1991a,b), further research could address specific application and residue goals in hydrodynamic systems.…”

Acrolein Reduces Biomass and Seed Production of Potamogeton pectinatus in Irrigation Channels

“…This response also has been reported for common elodea (Elodea canadensis Rich.) (Bowmer and Smith 1984;.…”