44 BULLETIN 1451, U. S. DEPARTMENT OF AGRICULTURE 
of two kinds: (1) Treatment of individual, marked barberry bushes 
with different chemicals; and (2) treatment of all the barberries 
growing in a certain area with one chemical. 
Experiments with 37 different chemicals are reported. These in- 
cluded (1) inorganic salts, (2) acids and acid formers, (3) gas- 
forming substances, and (4) oils and other organic substances. 
In the use of solutions the best results followed the application of 
the chemical as a drench about the base of the plant, whereas with 
dry substances, such as salt, best results were obtained by piling it 
in the base. Although all the shoots of an individual bush may be 
connected by stolons, each must receive a portion of the chemical in 
order to insure the death of all. Gas-forming substances and heavy 
oils failed to give uniformly satisfactory results. 
All factors considered, common salt (sodium chloride) proved to 
be the most satisfactory chemical for killing the common barberry. 
Kerosene and sodium arsenite in solution rank second and third, 
respectively. 
Sodium arsenite, although very effective, is extremely poisonous to 
livestock. Because of this danger it is not recommended for general 
use. 
