ROSIN AMINE D ACETATE (RADA) 



RADA is a water-soluble material that effectively controls fresh-water 

 algae in irrigation canals. It also prevents algae from forming on surfaces 

 of such structures as humidification systems and irrigation installations. 



NEW CHEMICALS AVAILABLE FOR EXPERIMENTAL AND TRIAL USE 



The new herbicides described in the following section have shown promise 

 in preliminary tests, but further evaluations are necessary before recom- 

 mendations for their use can be made. 



(1) 4-(2,4-dichlorophenoxy)butyric acid [ 4-(2,4-DB)] and 4-(2-methyl- 



4-chlorophenoxy)butyric acid 4-(MCPB) ] have shown promise for post 



emergence control of broadleaved weeds in (a) cereals underseeded with 

 certain forage legumes; (b) establishment of pure stands of forage legumes; 

 (c) forage legume seed-production fields; (d) flax; and (e) other weed-crop 

 situations. Legumes that are relatively tolerant to 4-(2,4-DB) include 

 white clover, alsike clover, red clover, alfalfa, and birdsfoot trefoil. 



(2) 2-chloro-4 > 6-bis(ethylamino)-s-triazine (simazin) is a wettable pow- 

 der with low solubility in water and in organic solvents. It is being tested 

 for pre-emergence weed control in corn, transplanted tomatoes, and 

 fruit crops. As a soil sterilant, simazin has been effective when applied 

 at heavy rates. Test results show that it may remain active in the soil for 

 long periods, but additional studies are needed to evaluate its residual ac- 

 tivity in soils. 



Simazin has low oral toxicity (LD^q = 5,000 mg./kg.) for mice. 



(3) 2,3,6-trichlorobenzoic acid (2,3,6-TBA) and several other isomers of 

 benzoic acid have shown promise as herbicides. The herbicide 2,3,6-TBA 

 is translocated in plants and is effective against a number of weeds that 

 other herbicides have failed to control. Ithasbeen used with some success 

 as a pre-emergence spray for weed control in corn. It is effective as a 

 post-emergence spray for the control of wild garlic, annual weed brome 

 grasses, quackgrass, some species of brush, several perennial weeds, 

 and certain other weeds that are serious pests in lawns and turf. It has 

 residual herbicidal activity in the soil. 



(4) Ethyl di-n-propylthiocarbamate (EPTC) has been used successfully 

 in preliminary trials as a pre-emergence herbicide to control annual 

 grasses and many broadleaved weeds in forage legume seedlings and in 

 certain other field and horticultural crops. It remains active in the soil 

 for short periods. EPTC is formulated as an emulsifiable concentrate, is 

 stable, and apparently noncorrosive. 



(5) 3,5-dimethyltetrahydro- 1 ,3,5,2H thiadiazine-2-thione (DMTT) is a 

 volatile soil sterilant that can be applied without the use of an airtight cover 

 over the soil for control of weeds, soil fungi, and nematodes. It may be 

 applied as a dry powder, or as a spray (wettable powder). After applica- 

 tion in either form, the material is mixed into the soil to a depth of about 

 6 inches. Best weed control has resulted when this treatment has been 

 followed by irrigation with at least 1 inch of water. A 21-day interval 

 should elapse between time of treatment and planting crops. 



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