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

Abstract

Chemical weed control with acrolein has been shown to be a lower cost method for reducing submerged plant biomass of sago pondweed in the irrigation district of the Lower Valley of Rio Colorado, Argentina (39°10′S–62°05′W). However, no experimental data exist on the effects of the herbicide on plant growth and its survival structures. Field experiments were conducted during 3 yr to evaluate the effect of acrolein on growth and biomass of sago pondweed and on the source of underground propagules (i.e., rhizomes, tubers, and seeds). Plant biomass samples were collected in irrigation channels before and after several herbicide treatments. The underground propagule bank was evaluated at the end of the third year. Within each treatment, plant biomass was significantly reduced by 40 to 60% in all three study years. Rapid new plant growth occurred after each application; however, it was less vigorous after repeated treatments. At the end of the third year at 3,000 m downstream from the application point, plant biomass at both channels ranged from 34 to 3% of control values. Individual plant weight and height were affected by acrolein treatments, flowering was poor, and seeds did not reach maturity. After 3 yr, acrolein did not reduce the number of tubers. However, they were significantly smaller and lighter. Rhizomes fresh weight decreased by 92%, and seed numbers decreased by 79%. After 3 yr of applications, operational functioning of the channels could be maintained with fewer treatments and lower concentrations of acrolein.

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

“…Multiple linear regression results of the data indicated that plant height is a significant factor when considering susceptibility to acrolein. Bentivegna and Svachka (1997) reported a major reduction of plant biomass when the plants were <45 cm in height; only plants below that size were totally eliminated (Bentivegna et al. , 2004).…”

“…This species undergoes an initial growth phase early in the spring (late August to September), followed by an exponential growth from October to December or February. Higher P. pectinatus biomass accumulation occurred during February and March, with a maximum of 1654 g dry weight (DW) m −2 and an absolute growth rate of 9 mg day −1 (Bentivegna et al. , 2004).…”

Concentration–Exposure Time Relationships for Controlling Sago Pondweed (Stuckenia pectinata) with Endothall

“…Nuisance populations of sago pondweed in irrigation canals are traditionally managed with acrolein or xylene (dimethylbenzene) (Bentivegna et al 2004;Gallagher and Haller 1990;Hansen et al 1983). These chemicals have maintained U.S. Environmental Protection Agency registrations for irrigation canals in the western United States because they have short exposure requirements, no irrigation restrictions, and do not persist in aquatic environments (Netherland et al 1998).…”