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Submitted to: Hydrobiologia
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/8/1997 Publication Date: N/A Citation: N/A Interpretive Summary: The submersed aquatic weed Hydrilla was introduced in the US from India in the 1950s'. It has severely impacted the use of fresh water resources throughout the sun-belt states as well as the NE and NW states. It efficiently reproduces vegetatively through tuber-like structures which develop in bottom muds and through vegetative buds on the plants' stems. We have been evaluating world wide accessions of this plant and have determined that many varieties of the plant not yet introduced in the US, have far greater ability to dominate national waters than those already present. In our most recent investigations, Hydrilla races from Japan and Poland were found to produce vegetative propagules throughout the year, not only during short-days of fall and spring. This characteristic enhances the ability of this plant to invade and dominate aquatic habitats and to further obstruct utilization of water resources for agriculture and recreation. Preventative measures should be implemented to halt further importation of this noxious weed. Technical Abstract: Three races of hydrilla observed to only produce turions were evaluated for photoperiod effects on propagule production. Greatest production was under short-days (10-h). These races from Japan and Poland produced both turions and turion-like tubers under long-day photoperiods (16-h) but production was most efficient under short- days. Increased propagule production under short- days may be compensation for decreasing photosynthetic activity at higher latitudes. Production appears only to be limited by temperature. |
