rapidly over the entire bottom. In succeeding periods of operation, 

 removal of fingerling fish then becomes difficult, for they become 

 stranded until too late to follow the receding water. Stampeding 

 is common in fingerling bass, and it may be fatal in the late stages 

 of draining a pond as the young fish may hide until stranded. 



Willows are a constant concern to fish culturists, because 

 they often establish themselves on the banks of ponds where they 

 become hideouts for muskrat burrows or fish enemies, or a hindrance 

 to the cutter bars of mowing machines. 



Among the important floating-leafed aquatic plants in ponds 

 and small lakes are water lilies, water hyacinths, watershield, 

 water lettuce, and the duckweeds. Many of these plants have 

 waxy coatings on their leaves which resist penetration of chemicals 

 unless oil carriers or sticker-spreaders are used. 



2.4-D, 2,4,5-T, etc. 



One of the most effective, economical, and safest herbicides 

 for control of emergent and floating- leafed aquatic plants is the 

 phenoxyacetic compound 2 ,4-dichlorophenoxyacetic acid (2,4-D). 

 This is the growth regulator type of weed killer which is absorbed 

 by affected plants and translocated to all of their parts. ]^f 

 Effects on aquatic plants are manifested in a number of ways. 

 For example, the petioles, the long slender stems which support 

 the leaves of water lilies, curl when affected by 2,4-D. In the 

 pond weeds (Potomogetons) , effects are manifested by rapidly- 

 growing shoots which appear in the axils of leaves, or by defolia- 

 tions of the stems. Plants affected by this chemical may grow 

 themselves to death, or simply wilt and die from the toxic effects. 

 Most emergent plants turn brown when affected, but in cattails and 

 many other erect plants, the test of effectiveness of treatment is 

 examination of the underground stems, which are a means of propaga- 

 tion or storage of food for new growths. If these root-stocks are 

 in the process of decay, the plants are dead. Even an effective 

 treatment may not kill all plants in a single application. 



2,4-D in its pure form as an acid powder is insoluble in water, 

 but it is readily dissolved in the co-solvents triethanolamine and 

 tributylphosphate, one pint and one quart, respectively, of which 

 will dissolve a pound of 2,4-D acid powder. The former solvent is 

 used for introduction of the chemical into water solutions, while 

 tributylphosphate solutions are readily miscible with kerosene, 

 diesel and other oils. 



1^/ Seaman (1958, p. 212) records work in his department that 

 indicates that 2,4-D moves upward better than downward in 

 alligator weed. 



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