30 LOTUS 



CONTROL 



Control can be accomplished rather easily, by herbicides, drown- 

 ing, or mowing. The best time is the summer season, when the 

 plants are flowering freely. Eradication must be complete, else 

 rapid spread of surviving plants may soon reestablish beds. 



In some localities, a biological means of control is evident; 

 larvae of the leaf beetle Donacia hypoleuca bore into petioles below 

 water level and sometimes destroy extensive beds in deep water. 

 Only once in a total of 10 years did this insect provide conspicuous 

 control of lotus at Reelfoot Lake in Tennessee. 



HERBICIDES 



A single herbicide spraying of 2,4-D (either salts or esters) at 

 2 to 4 pounds of acid equivalent per acre can give nearly complete 

 control of lotus. 



DROWNING 



Where water levels can be managed readily, drowning of lotus 

 is the easiest and most economical control procedure. A rapid 

 rise of 30 to 36 inches (to cover the leaves) is needed and must 

 be maintained at this high stage for at least 12 days. Plants are 

 more susceptible when flowering freely. Turbidity of water also 

 increases effectiveness. Drowning of lotus sometimes occurs nat- 

 urally, after heavy rains and flooding. 



cuniNG 



In general, mowing of lotus is likely to be less practical* than 

 the use of 2,4-D. Underwater mowing of leaf and flower stalks 

 in shallow water, less than 2V2 feet deep, is generally ineffective. 

 In water 3 to 5 feet deep, 80% to 100% control has been obtained 

 by two cuttings. Occasionally, as when the water is dark, one 

 cutting may be sufficient. A commercial weed cutter tested in 

 Reelfoot Lake was found to be impractical for this purpose be- 

 cause of stumps or snags present. 



REFERENCES 



1950. Waterfowl Habitat Improvement on Reelfoot Lake. John H. Steenis. Jour. 



Tennessee Acad. Sci. 25 (1). 

 1950. Studies on the Use of Herbicides for Improving Waterfowl Habitat in Western 



Kentucky and Tennessee. John H. Steenis. Jour. Wild. Mgt. 14 (2). 

 1950. Leaf Beetles vs. Lotus. John H, Steenis and Robert T. Mitchell. Jour. 



Wild. Mgt. 14 (4). 

 1945. A Progress Report on the Marsh and Aquatic Plant Problem; Reelfoot Lake. 



John H. Steenis and Clarence Cottam. Jour. Tennessee Acad. Sci. 20 (1). 

 1944. The Biology of the American Lotus, Nelumbo liUea (Willd.) Pers. Thomas F. 



HaU and William T. Penfound. American Mid. Nat. 31 (3). 



