Life cycle and growth ofPotamogeton crispus L. in a shallow pond, ojaga-ike

Evaluation of lakewide, early season herbicide treatments for controlling invasive curlyleaf pondweed (Potamogeton crispus) in Minnesota lakes

“…Our littoral means incorporated data from many sites with a wide range of curlyleaf densities, including samples from sites with no curlyleaf growth and deeper sites with little or no turion production on standing plants. Similarly, the percentage contribution of turions to total curlyleaf biomass in our reference lakes (9%) was substantially lower than the percentages reported by Rogers and Breen (1980; 23% of total biomass), Kunii (1982;42%), and Woolf and Madsen (2003;22-58%) from untreated lakes, and our estimate of the number of turions produced per dry gram of curlyleaf shoot biomass in reference lakes (2.9 turions/dry g) was about one-half of that reported by Kunii (1982) from untreated lakes (∼6 turions/dry g, estimated from plotted data). However, the mean dry mass of individual newly-produced turions in our reference lakes (43 ± 4 mg/turion) was fairly similar to the 53 mg/turion reported by Kunii (1982).…”

“…Much of this between-year variation was likely attributable to regional climatic differences that enhanced May curlyleaf growth in 2006 and 2007 and delayed curlyleaf growth in 2008 and 2009. Other studies have suggested that early season curlyleaf growth can be affected greatly by the availability of light during the winter (a function of snowfall and duration of ice cover) and spring water temperatures (Kunii 1982, Tobiessen and Snow 1984, Valley and Heiskary 2012. These weather-related conditions likely affected curlyleaf growth similarly in both our treated and reference lakes (similar geographic locations), but due to the asynchrony of the initial treatments among treated lakes we were not able to discern weather effects from herbicide effects within individual treatment years.…”

“…In reference lakes, turion abundance in sediments was much more variable between years than anticipated, suggesting that differences in weather or in-lake conditions affected the amount of turion production or sprouting that occurred in each year, as suggested by Sastroutomo (1980Sastroutomo ( , 1981 and Kunii (1982). From a management perspective, this suggests that herbicide treatment in years with enhanced turion sprouting would likely result in the greatest reductions of turion abundance (through sprouting without replacement).…”

Short-term declines in curlyleaf pondweed in Minnesota: potential influences of snowfall

“…The rate and timing of temperature changes and peak temperatures can influence growth, turion production, and senescence of curlyleaf pondweed, with critical surface water temperatures ranging from 19 to 25 C (Sastroutomo et al 1979, Kunii 1982, Chambers et al 1985, Woolf and Madsen (Table 4), which would presumably favor curlyleaf pondweed growth. Second, in 2010, an extended period of warm temperatures across the state in late winter and early spring melted ice approximately 2 weeks earlier than the statewide median (Table 4).…”

Effect of sediment deposition on turion sprouting and early growth ofPotamogeton crispusL.

“…The life history of P. crispus differs from most submerged species (Kunii 1982). When the water temperature begins to rise in the spring, it grows rapidly (Stuckey 1979;Sastroutomo 1981;Rogers & Breen 1980).…”