A formulation of acrolein is available for treatnnent of irrigation and 

 drainage canals by licensed operators with especially adapted equipment. 

 Acrolein is effective at low concentrations for control of submersed aquatic 

 weeds and algae in ponds, lakes, and other bodies of static w^ater without 

 serious losses of fish. 



By using special application techniques, fish can be herded without injury. 



Acrolein has high oral toxicity (LDjo = 46 nng,/kg.) for rats. 



NEW CHEMICALS AVAILABLE FOR EXPERIMENTAL TRIAL 



The new herbicides described in the following section have shown pronnise 

 in preliminary investigations, but further evaluation studies are necessary 

 before effective guides for their use can be developed. 



(1) 3-amino- 2, 5 -dichlorobenzoic acid [amiben] has shown pronnise as a 

 pre-emergence treatment for the control of many annual broadleaved weeds 

 and weed grasses in soybeans, lima beans, and strawberries. Preliminary 

 research w^ith this herbicide has been successful on a number of other crops. 

 Amiben is relatively low in oral toxicity (LD-g - approximately 3,500 mg./kg.) 

 for rats. 



(2) 2, 3, 6-trichlorophenylacetic acid [fenac] has shown promise for control 

 of quackgrass and annual broadleaved weeds and weed grasses when applied 

 in the fall or spring and incorporated by tillage. Corn has been grown success- 

 fully following pre-planting treatments at low rates in the spring. It is also 

 effective on bindweed and certain other perennials. Pre-planting soil- 

 incorporated treatments w^ith low rates of fenac have been effective in 

 controlling witchweed. Oral toxicity (LDjq = 2,500 to 3,000 mg./kg.) is 

 relatively low for rats. 



(3) 2, 3, 6-trichlorophenylacetamide has been compared to fenac in pre- 

 liminary evaluation studies. Weeds respond more slowly to the acetamide 

 and it remains active in the soil for longer periods than fenac. 



(4) tris(2, 4-dichlorophenoxyethyl)phosphite [2,4-DEP] has shown promise 

 as a pre-emergence herbicide for control of a number of annual broadleaved 

 weeds and weed grasses in certain field and horticultural crops. Oral toxicity 

 (LD5Q = 850 t 140 mg./kg.) is relatively low for rats. 



(5) 4-chloro-2-butynyl N-(3-chlorophenyl)carbamate [barban] is an effec- 

 tive herbicide for wild oats in wheat and barley when applied to wild oats in 

 the 2-leaf stage. Studies on the control of wild oats in sugar beets, flax, and 

 canning peas also appear promising. Oral toxicity (LD5Q = 1,300 mg./kg.) is 

 relatively low for rats. 



(6) 2, 3-dichloroallyl diisopropylthiolcarbamate (cis and trans forms) is 

 effective in controlling wild oats in barley, flax, and sugar beets when 

 applied as a pre-planting soil-incorporated treatment. Experimental studies 

 have indicated that certain horticultural crops are tolerant to this herbicide. 

 Oral toxicity (LD^q ~ 250 to 375 mg./kg.) is intermediate for rats. 



(7) N-(3-chloro-4-methylphenyl) -2-methylpentanamide has shown promise 

 as a post-emergence treatment for control of small (less than 2 inches) 

 annual broadleaved weeds and weed grasses in tomatoes. Oral toxicity 

 (LD5Q = more than 10,000 mg./kg.) is low for rats. 



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