For such plants as lotus ( Nelumbo ) , water lilies ( Nympheae 

 and Nuphar ) , watershield (Brasenia) , bulrush ( Scirpus ) , cattail 

 ( Typha ) , parrots feather ( Myriophyllum ) , and duckweed ( Lemna ) , 

 the same quantity of 40 per cent 2,4-D ester (1 pint) per 10 

 gallons of No. 2 fuel oil are suggested. Snow (1949, 1959) observed 

 that sprays containing as low as 0.25 per cent 2,4-D esters in 

 No. 2 fuel oil, or in water containing a detergent (Tide) as a 

 surficant were effective in controlling arrowheads, parrot feather, 

 duckweed, and willows. 



Dalapon at 10 - 20 pounds acid equivalent per acre, or 5 

 pounds amitrole plus 5 pounds dalapon per acre is effective on 

 cattails, reedgrass and other resistant forms. Timmons et . al 

 (1958, p. 408) described the advantages of split applications of 

 amitrole and dalapon in control of cattail. The first treatment 

 was made at a pre-heading stage late in June, and the second 

 treatment was made in early September before the first killing 

 frost. Rates of 5 pounds per acre of amitrole and 10 + 10 of 

 dalapon in a split treatment give effective control. 



Water hyacinths can most effectively be controlled by low- 

 pressure spraying of the amine salt of 2,4-D at 4 pounds of acid 

 equivalent per acre and 80 - 100 gallons of solution per acre, 

 but good control is often obtained with 2 or 3 pounds acid equivalent 

 per acre. The reader is referred to "Improving Duck Marshes by 

 Weed Control" by Martin et al . (1957), for methods of control of 

 several important marsh plants that are less frequently encountered 

 by the pond owner or operator. Snow (1958) also gives the results 

 of experiments in control of marginal weeds about ponds, together 

 with recommended treatment rates. 



Danger of Aerial Drifts in Spraying of the Formagenic Compounds 



Spraying with 2,4-D or 2,4,5-T and similar powerful chemicals 

 can produce serious damage to many valuable agricultural crop 

 plants, such as cotton and grapes, if done at a time when the 

 chemical can be drifted by breezes or winds. Local damage to such 

 garden plants as tomatoes and cucumbers is possible when marginal 

 plants about fish ponds are sprayed on windy days. 



The problem of extreme sensitivity of some crop plants to 

 2,4-D has been met by the formulation of less-volatile compounds such 

 as the sodium salts of 2 ,2-dichloropropionic acid (dalapon) and 

 2(2 ,4,5-trichlorophenoxy) propionic acid (silvex) . The former is 

 now used at a rate of 7 pounds acid equivalent per acre to control 

 phragmites, and the latter is used in rice fields for control of 

 herbaceous plants. 



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