

ERADICATING POISOn VJJ 



Many ways have been tried for eradicating poison ivy. Spraying with chemicals 

 appears to be the most satisfactory. Of the many chemicals tried, ammonium 

 sulfamate and 2, Ix, S trichlorophenoxyacetic acid have given best results. 



Poison ivy is very susceptible to 2, \\, 5 trichlorophenoxyacetic acid, 

 com^Bonly kno;vn as 2li5, or 2, U, 5-T or ^-T. This is one of the "growth substances" 

 and, therefore, is effective in relatively small quantities and, like 2,U-D, it is 

 a selective weed killer. It is non-inflammable, noncorrosive and nontoxic to 

 animals. It is, hovrever, very difficult to clean from a sprayer. It is strongly 

 recommended that any sprayer used for this material not be used for applying fungi- 

 cides or insecticides. If it must be used for fungicides or insecticides, fill it 

 with 1% household ammonia solution, pump some through the hose and nozzle, and 

 let stand over night. Then wash thoroughly with water. 



Also, a combination of 2,l4,5-T vdth 2,U-D, usually sold under the name "brush 

 killer," may be used. The ester forms of these materials are the most effective 

 and are most apt to cause trouble because of their volatility. Ask for low volatile 

 forms and do not use them too close to gardens or valuable shrubs. They may be 

 applied any time vrtiile the poison ivy leaves are fully expanded. These materials 

 can also be used in high concentrations in oil (kerosene, fuel or diesel oil) 

 during the dormant season. Dormant treatment is effective if all stems are sprayed. 

 Without their leaves small stems of poison ivy hidden in the grass may be missed. 

 For this reason summer treatment usually gives best results. The manufacturer's 

 directions on the container should be followed as to dilution. 



Ammonium sulfamate is a very good eradicant for poison ivy. It is noninflam- 

 mable, nontoxic, very soluble and easily dissolved and cleaned from a sprayer but 

 it is very corrosive on metals. Immediately after its use the spray equipment 

 should be v^ashed thoroughly inside and out. Some baking soda or spray lime added 

 to the rinse water helps. It is nonselective and vdll severely injure or kill most 

 plants sprayed with it. It is nonvolatile and can be used close to gardens 

 provided spray drift is kept off valuable plants. It is very toxic to peaches and 

 cultivated blueberries and should not be used around these fruits. It can be used 

 at 3A to 1 pound per gallon of ^vater. The ivy should be thoroughly wetted \^th 

 the spray. Application may be made any time the loaves are fully expanded until 

 frost but June or early July applications usually give best results. 



In this type of spraying lov; pressure (UO-100 pounds per square inch) is 

 desirable because the spray droplets are larger and there is less danger from spray 

 drift. 



John S. Bailey 



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" Fruit Thinning with Chemical Sprays " A nev;- publication on this 

 subject, Circular 567, is now available from the Office of 

 Information, USDA, Washington 25, D.C. V/hile the effects of 

 recent chemical thinning tests in i.iassachusetts are being watched 

 with interest, a study of the nation-wide recommendations and 

 results is suggested. Every grower interested in getting better 

 results from his hormone thinning applications should obtain and 

 study this new Circular 86?. 



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