Madsen, J.D. and C.S. Owens, 1998. Seasonal Biomass and Carbohydrate Allocation in Dioecious Hydrilla, US Army Corps of Engineers.

Reprinted from Journal of Aquatic Plant Management (1998) 36(2): 138-145

ABSTRACT
The phenology of dioecious hydrilla (hydrilla verticillata (L.f.) Royle) was studied to discern seasonal low points in the carbohydrate storage of this nonindigenous weedy aquatic plant. Hydrilla was sampled monthly from two outdoor ponds (0.3 ha each) at the Lewisville Aquatic Ecosystem Research Facility (LAERF) in Lewisville, Texas, from January 1994 through July 1995. Monthly samples were dried to obtain biomass dry weight (g m^-2) and analyzed for total non structural carbohydrates (TNC), free sugars, and starch. Results indicated the lowest amount of stored TNC occurred in July for 1994 and in June for 1995, with stolon (6%), upper stem (6%)) root crown (10%) and lower stem (11 %). Tubers (65%) and turions (60%) exhibited their lowest TNC concentrations when the total plant stores of TNC were at their lowest point. Biomass increased from May through September, regrowing from overwintering shoots and root crowns, but not tubers. In addition to the hydrilla pond sampling, containers planted with hydrilla were harvested from January 1995 through December 1996. Monthly samples were likewise analyzed for carbohydrate storage. The lowest concentrations of stored carbohydrates occurred in June for both growing seasons. These studies provide more insight into the timing of major allocation shifts in the hydrilla seasonal growth cycle for the purpose of optimizing management techniques.

Entire Paper
Contact: John Madsen, US Army Corps of Engineers, Waterways Experiment Station, CEWES-ES-P, 3909 Halls Ferry Road, Vicksburg, MS 39180
Keywords: Hydrilla, Basic_biology, Aquatic_plant_management
Product Type: Research, Basic_biology
User Type: Resource Management