Walker observed that over 40 p. p.m. of sodium endothal failed 

 to ill fish when this chemical was used in the liquid and 5 per 

 cent granular form. No adverse affects upon the numbers of bottom 

 animals were noted from treatments to control the above pondweeds . 



Hyamine 1622 



Bond (1960) considers Hyamine 1622 (paradiisobutyl phenoxy 

 ethoxy ethyl dimethyl benzylammonium chloride) a promising herbicide 

 for control of Elodea densa in ponds and ditches. He considered 

 the cost of the material probably too high for use in large (300 to 

 3,000 acres) lakes. His laboratory screening tests showed it to be 

 toxic to E lodea densa at 2 p. p.m. and open plot applications in 

 dense stands of this plant indicated that Hyamine 1622 will control 

 Elodea at about 4 p. p.m. The 48-hour TLjn for coho salmon fingerlings 

 is 53 p. p.m. in soft water. 



Simazine 



Simazine is available in 50 and 80 per cent wettable powders 

 (Simazine 50 W and 80 W) and in an 8 per cent pelletized form. In 

 Missouri Federal Aid Project F-l-R-9 experiments, Charles R. Walker 

 observed that the above-named species of Potamogetons treated with 

 50 per cent wettable powder as a spray, at a rate of 10 p. p.m. 

 active ingredient, gave most effective results. The minimum lethal 

 concentration of this chemical to fish was over 40 p. p.m. At about 

 $3.00 per pound, the treatment of an acre five feet deep could be 

 very expensive, costing about $240 per acre. 



When 20 pounds active ingredient per acre of the 8 per cent 

 pelletized Simazine was tried, good results were also obtained. 

 Ten pounds (1.0 p. p.m.) per acre of this material controlled 

 Potamogeton diversifolius in a pond throughout a season. No 

 adverse effects upon numbers of bottom animals were noted by Walker 

 for either Simazine or sodium endothal. 



Silvex 



One of the promising new chemicals is 2- (2 ,4,5-trichlorophenoxy) 

 propionic acid or Silvex. Younger (1958) found that 2.0 parts per 

 million controlled such species as waterweed ( Anacharis ) , mud plantain 

 ( Heteranthera ) , water milfoil ( Myriophyllum ) and bladderwort 

 ( Utricularia ) . One part per million controlled yellow water lily 

 ( Nuphar ) and 0.5 p. p.m. white water lily ( Nympheae ) . 



Thomaston, et . al (1960) obtained control of Myriophyllum 

 brasiliense , M. heterophyllum , and Utricularia with 1.0 part per 

 million. Three pounds active ingredient per acre controlled white 

 water lily ( Nympheae ) , lotus ( Nelumbo ) , watershield (Brasenia) 

 schreberi ) , and softrush (Juncus effusus) . 



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