Field studies of delta duckpotatoes (Sagittaria graminae var. platyphylla) disclosed that plant density was 1.5 times greater in wildlife exclosures than in control areas. Tuber production where nutrias (Myocastor coypus) and ducks were excluded was 652.3 g/m2• Tuber production was considerably less in plots subjected to foraging by wildlife (nutria foraging only: 104.7 g/m2, duck foraging only: 75.8 g/m2 , nutria and duck foraging: 64.8 g/m2 ). Tubers were found to a soil depth of 30 em but where animals were excluded greatest production (40.3%) was at the 10-15 cm depth. Nutrias foraged to the 30 cm depth but most duck foraging was from the 0-15 cm depth. Tank studies disclosed that a deep (30 cm), constant water depth produced taller plants and enhanced seed production, but water depth variation had no effect on tuber production. Constant 20 and 30 cm water depths encouraged above-ground biomass production. Of seed storage methods examined, air-dried seed retained viability better than seeds not dried. Air-dried and refrigerated seeds germinated better than those stored at room temperature. Chilling and gibberrellic acid treatment enhanced germination. Germination was better in low salinities «5.0 ppt). Tubers stored moist at 30 C sprouted best (43.0% ), while no air-dried tubers sprouted.
