- Author: Guy B Kyser
- Author: John Madsen
- Author: John Miskella
- Author: Jon O'Brien
- View More...
From the Journal of Aquatic Plant Management—Special Issue Vol. 59s 2021
New herbicides and tank mixes for control of waterhyacinth in the Sacramento–San Joaquin Delta
Guy B. Kyser, John D. Madsen, John Miskella, and Jon O'Brien
Abstract
The Sacramento–San Joaquin Delta is the largest freshwater estuary on the West Coast of the United States. Delta habitat and economic utility are compromised by waterhyacinth, a floating aquatic weed. Standard control measures for waterhyacinth include foliar treatment with glyphosate or 2,4-D. We have conducted trials over three seasons to evaluate efficacy of newly registered, low–userate aquatic herbicides. In 2017, we evaluated waterhyacinth control using carfentrazone (133 g ai ha-1), flumioxazin (322 g ai ha-1), imazamox (280 g ae ha-1), and florpyrauxifen-benzyl (29.4 and 58.8 g ai ha-1), as well as various tank mixes, compared with a standard rate of glyphosate (1,681 g ae ha-1). Plots were established in floating 1-m2 quadrats, and treatments were replicated four times. All treatments were applied in 935 L ha-1 solution with 3.5 L ha-1 nonionic surfactant. We also included treatments with glyphosate (1,681 g ae ha-1) in lower spray volumes of 234 and 468 L ha-1. We collected biomass samples at 8 wk after treatment (WAT). Three treatments reduced waterhyacinth biomass by > 95%: florpyrauxifen-benzyl (58.8 g ai ha-1), flumioxazin + imazamox (322 + 280 g ai/ae ha-1), and the 468 L ha-1 application of glyphosate (1,681 g ae ha-1). Tank mixes (flumioxazin + imazamox, carfentrazone + imazamox, carfentrazone + glyphosate, and flumioxazin + glyphosate) gave approximately additive control. Florpyrauxifen-benzyl and flumioxazin + imazamox may be effective alternatives to glyphosate for controlling waterhyacinth with reduced rates of active ingredient. Glyphosate applied in a spray volume of 468 L ha-1 produced better control than the same rate of glyphosate in 935 L ha-1, suggesting that spray-volume optimization may be a useful topic for future research.
Delta Region Areawide Aquatic Weed Project website
Authors
- Guy B. Kyser, Specialist, Department of Plant Sciences, University of California, Davis (gbkyser@ucdavis.edu)
- John D. Madsen, Research Biologist, USDA–ARS ISPHRU, Department of Plant Sciences, University of California, Davis (jmadsen@ucdavis.edu)
- John Miskella, Biological Research Technician, USDA–ARS ISPHRU, Department of Plant Sciences, University of California, Davis (jmiskella@ucdavis.edu)
- Jon O'Brien, Environmental Program Manager, Department of Parks and Recreation, California State Parks
- Author: John Miskella
- Author: John Madsen
- Posted by: Gale Perez
Mapping waterhyacinth drift and dispersal in the Sacramento–San Joaquin Delta using GPS trackers
John Miskella and John Madsen
Abstract
Waterhyacinth [Eichhornia crassipes (Mart.) Solms)] is a perennial free-floating aquatic plant species native to the Amazon region of South America. It has become invasive around the world, including in the Sacramento–San Joaquin Delta in central California. From June 2016 to February 2018, a study was conducted to determine the extent that wind, tidal movement, and mass flow drove the dispersal of waterhyacinth mats in the Delta. Global positioning system (GPS) trackers were deployed to track the movement of waterhyacinth mats, recording the location, speed, and direction of movement at 15-s intervals. The relationship between mat size and distance traveled was analyzed using linear regression and did not show correlation (R2 = 0.0462, P = 0.0738). The movement of each waterhyacinth mat containing a GPS tracker was compared to the wind and water movement during the period the tracker was deployed. The direction of water movement, influenced by both mass flow and tides, aligned more closely with the direction of waterhyacinth mats, with a mean difference of 0.31 radians (rad) (17.75°), than the wind direction did, with a mean difference of 1.31 rad (75.34°). The pattern of plant mat movement observed using the GPS trackers presents a difficult management situation, with the waterhyacinth mats moving back and forth with tidal movement.
Delta Region Areawide Aquatic Weed Project website
Authors
- John J. Miskella, Biological Research Technician, USDA–ARS ISPHRU, Department of Plant Sciences, University of California, Davis (jmiskella@ucdavis.edu)
- John D. Madsen, Research Biologist, USDA–ARS ISPHRU, Department of Plant Sciences, University of California, Davis (jmadsen@ucdavis.edu)
/h3>/span>
- Author: John Madsen
- Author: Christy Morgan
- Posted by: Gale Perez
Water temperature controls the growth of waterhyacinth and South American sponge plant
John D. Madsen and Christy M. Morgan
Abstract
We examined the effect of water temperature on the growth of two free-floating aquatic species in this study: waterhyacinth [Eichhornia crassipes (Mart.) Solms] and sponge plant [Limnobium laevigatum (Humb. & Bonpl. Ex Willd.) Heine]. Waterhyacinth has been rated as the worst aquatic weed worldwide. A native of South and Central America, it is a recurring management issue in tropical and subtropical freshwater bodies in the United States. Sponge plant, native to southern Mexico, Central America, South America, and the Caribbean, was first detected in California in 2003. We studied the growth of these two species with two 6-wk growth studies (for each species), at water temperatures of 15, 20, 25, and 30 C. All temperatures were replicated in four tanks, for a total of 16 tanks. Waterhyacinth biomass was over 2,000 g dry weight (DW) m--2 for plants grown at 25 and 30 C by 42 d after start (DAS). Waterhyacinth density reached almost 800 rosettes m_2 at 42 DAS at 25 and 30 C. Waterhyacinth relative growth rate (RGR) reached 0.099 d--1, for a doubling time of 7.0 d. Sponge plant biomass at42 DAS was 400 g DW m--2 at 25 and 30 C. Density was as high as 3,900 rosettes m--2 at 42 DAS grown at 25 C. Sponge plant RGR was 0.12 d--1 at 25 C, for a doubling time of 5.7 d. The invasive potential of sponge plant has been demonstrated in this study.
Authors
- John D. Madsen, Research Biologist, USDA–ARS ISPHRU, Department of Plant Sciences, University of California, Davis (jmadsen@ucdavis.edu)
- Christy M. Morgan, Biological Research Technician, USDA–ARS ISPHRU, Department of Plant Sciences, University of California, Davis
/h3>/span>