Aquatic Plant Control Research Program. Simulated Mechanical Control of Aquatic Plants in Buffalo Lake, Wisconsin.

To determine the operational time required to mechanically control nuisance-level growth of aquatic plants in Buffalo Lake, Wisconsin, a computer model HARVEST was used which simulates all important steps in a mechanical control operation. Model inputs include plant density, distance to nearest disposal site, and mechanical and performance specifications for the harvesting system used. Plant densities were determined at two different times during the growing season by conducting a quantitative field sampling program coupled with aerial photography. A treatment area was selected which consisted of boat lanes covering approximately 20 percent of the area in the eastern two thirds of the lake. The Aquamarine H8-650 and H-400 harvester were selected for simulation. Mechanical control operations were simulated in the treatment area for the two summer periods using each harvester working alone and with a single Aquamarine T-650 transport unit. Surface-topped growth of aquatic plants within the harvestable portion of Buffalo Lake during early and late summer periods covered 35 and 50 percent, respectively, of that area. Harvestable density within the treatment area during early and late summer periods averaged 5.9 and 7.9 tonsacre, respectively. Coontail Ceratophyllum demersum was the dominant plant species encountered. Predicted control operation times ranged from 215 to 440 hr for the early summer period and 297 to 627 hr for the late summer period. Predicted production rates were greatest for the H8-650 harvester working with a transport unit.