Controlling Aquatic Plants When left uncontrolled aquatic plants

Controlling Aquatic Plants

When left uncontrolled, aquatic plants • Impair recreational uses • Cause foul odors and bad taste to drinking water • Cause fish kills • Stunt fish growth • Reduce water depth as plants die • Increase nuisance insect populations • Decrease property values • Cause accidental drowning • Block water flow in irrigation and drainage ditches

A problem when vegetation covers more than 20 -25% of shallow area more than 50% of a body of water

Two groups of aquatic plants Algae Flowering Plants

Algae • Microscopic algae (phytoplankton) • Filamentous algae (moss) • Chara (stonewart)

Flowering plant categories • Emergent plants • Rooted floating plants (emergent) • Free floating plants • Submersed plants

Emergent plants • rooted in sediment • most of foliage above water • cattails, bulrushes, willows • most “wetland” plants are emergent ©USDA, NRCS @ PLANTS

© USDA, NRCS @ PLANTS

© USDA NRCS, 1995 Midwestern Wetland Flora @ PLANTS

Rooted floating plants • lilies, spatterdock • rooted in sediment • leaves and flowers float on water surface © USDA, NRCS

Free floating plants • duckweed, water meal • not rooted in sediment • freely float in water © USDA, NRCS, 1997 Northeastern Wetlands Flora @ PLANTS

Submersed plants • elodea, pondweeds • rooted in sediment • only flowering structure emerges above water surface © NRCS @ PLANTS © USDA, NRCS, 1997 – Northeastern Wetlands Flora @ PLANTS

Pond Management– What’s your goal? • • • Recreational fishing Swimming & boating Wildlife habitat / aesthetics Livestock water supply Aquaculture Storm water management

Aquatic Plant Control – Physical • • • Benthic barriers Drawdown Mechanical removal Dredging Dyes

Aquatic Plant Control – Biological • Grass carp

Aquatic Plant Control – Chemical • Identify the problem plant • Use only EPA registered and approved products • Read and follow all label directions • Timing – late spring, early summer • Temperature – Over 65° • Retreat?

Calculating treatment area Herbicide applications made on two parameters– • Surface area basis for control of rooted floating and emergent plants • Volume basis for control of algae and submersed plants

Surface area • Rectangular area acres = length (ft) x width (ft) 43, 560 ft 2 • Circular area (radius measured in feet) acres = 3. 1416 x radius 2 43, 560 ft 2 • Triangular area acres = ½ base (ft) x height (ft) 43, 560 ft 43, 560 = number of square feet per acre

Depth • Measure – don’t assume • Measure at intervals, average together

Volume Acre-feet = surface area (acres) x average depth (ft) Example: Area = 240 ft x 120 ft 43, 560 ft = 0. 66 acre Average depth = 2+4+9/3 = 5 ft Volume = 0. 66 acre x 5 ft = 3. 3 acre-ft

Amount required Pounds required = 2. 7 lb x ppm desired x acre-ft (from label) Example: Required dose is 2 ppm. Amount = 2. 7 lb x 2 ppm x 3. 3 acre-ft = 16. 2 lb of product

Permits Private applicator permit Purchase and apply restricted-use pesticides to privately owned lake or pond, or drainage ditch. Commercial application of pesticides (for hire) requires a commercial license, Category 5. For information on pesticide permits contact Office of Indiana State Chemist 765/494 -1492

IDNR permit A permit from IDNR is required when • a lake resident treats more than 625 sq. ft; more than 25 linear ft along shore and in water deeper than 6 ft. • a biological organism (grass carp) is used to control plants. • mechanical control is used in areas larger than 625 sq. ft.

IDNR permit • Obtained from Division of Fish & Wildlife • $5 filing fee • IDNR Fish & Wildlife 402 W. Washington St. , Rm. W 273 Indianapolis, IN 46204 317/232 -4093