Submitted to: Journal of Aquatic Plant Management
Publication Type: Proceedings
Publication Acceptance Date: 5/8/2014
Publication Date: N/A
Technical Abstract: Waterhyacinth (Eichhornia crassipes) is a floating aquatic plant that can become a serious weed problem. It has been managed in the Sacramento Delta by a program using 2,4-D and/or glyphosate. Because previous work indicated that dilute acetic acid solutions prevented aquatic plant propagule sprouting, we performed experiments to assess its impact on waterhyacinth. Waterhyacinth from an outdoor culture (originally collected from White's Slough in the Sacramento Delta on 4/6/94) were treated with 3 levels of acetic acid (1, 2.5, and 5%) and a control in combination with four types of adjuvants. The acetic acid concentrations used are less than or equal to that of vinegar. Three replications, consisting of a single waterhyacinth growing in a 95 l barrel filled with water, were randomly assigned to each treatment. After an initial treatment, plants were treated again three weeks later. One week after the second treatment, plants were harvested. Number of green or brown leaves per plant were counted and the dry weight was determined after drying at 80 C for 7 days. We also measured N and C content (%). Acetic acid treatment significantly reduced the number of green leaves per plant and plant dry weight. Carbon content was unchanged and nitrogen content increased in treated plants. The four adjuvants performed similarly. This is potentially a new method for managing this weed.