Aquatic Plant Control Research Program. Feasibility of Relating Phenology and Carbohydrate Partitioning to Improve Aquatic Plant Control

Abstract : Phenology and carbohydrate literature for waterhyacinth (Eichhornia crassipes (Mart.) Solms), hydrilla (Hydrilla verticillata L.f. Royle), Eurasian watermilfoil (Myriophyllum spicatum L.), and alligatorweed (Alternanthera philoxeroides (Mart.) Griesb) was surveyed to assess the feasibility of using phenology/carbohydrate relationships for improving control tactics. Many studies have examined phenology of waterhyacinth, hydrilla, and Eurasian watermilfoil, but not alligatorweed. Phenology of monoecious and dioecious biotypes of hydrilla differs in growth pattern and propagule development. The monoecious biotype appears to be better adapted than the dioecious biotype to live at Northern latitudes because of its ability to produce more tubers and turions at lower water temperatures. A few investigations involving Eurasian watermilfoil and alligatorweed suggested that control efforts directed at the low ebb of carbohydrates will decrease biomass production. Little information on carbohydrate partitioning has been reported for waterhyacinth and hydrilla. Previous studies of these plants have not evaluated the role of starch reserves for plant survival. Environmental factors (e.g., temperature, light, and nutrients) have been shown to influence phenology and, by inference, carbohydrate partitioning. How these factors control carbohydrate partitioning in these plants is unknown. Phenological and carbohydrate relationships have not been fully developed to allow plant control programs to take advantage of weak points in a plant's life cycle. Keywords: Weed control; Aquatic weeds.