Seasonal Biomass and Carbohydrate Allocation Patterns in Southern Minnesota Curlyleaf Pondweed Populations

Four southern Minnesota populations of curlyleaf pondweed ( Potamogeton crispus L.) were sampled monthly from January 2001 to November 2002 to determine seasonal phenological, biomass, and carbohydrate allocation patterns. Low periods of carbohydrate storage in the seasonal phenological cycle indicate potentially vulnerable periods in the plant’s life cycle and may be the ideal time to initiate management and control efforts. Samples were separated into shoots, roots, inflorescence, and turions and then dried. Biomass (g m -2 ) and percent total nonstructural carbohydrates (TNC) were determined for each plant component. Total biomass peaked in May and June, and ranged from 122 to 190 g m -2 . Turion formation and flowering were observed to coincide with peak biomass. Peak turion TNC concentrations ranged from 44 to 66%. The low point of carbohydrate storage in all four lakes occurred between January and April 2002, indicating that early spring may be the best time to initiate management.