WHITE-PINE BLISTER RUST. 79 
reduced the number of uredinia, it did not entirely prevent their 
formation. 
The spraying of pines with fungicides apparently has not received 
much attention. It is reported that the infection of young seedlings 
of white pine has been controlled by spraying in Belgium (106). 
Pines have been treated in Europe by the application of various 
chemicals, but the following cases are the only ones where results 
are given. 
Hostermann (55) treated the affected parts of two Pinus strobus 
trees with 10 per cent and 20 per cent solutions of carbolineum. 
This was applied with a brush on April 28, 1908, before the secia 
matured, and again on May 12 and 18. The next spring, secia started 
to develop, and the treatment was repeated with a 50 per cent solu- 
tion of carbolineum. The tree was apparently unhurt, but in the 
spring of 1910 the fungus was still alive. 
In another case (102), where 15-year-old trees were badly attacked 
on the trunk and the leaves had turned noticeably yellow, the bark 
was scraped off and the area bandaged with " carbolineum avena- 
rius." A second tree was scraped and a 10 per cent solution of 
potassium permanganate applied. On a third tree a 1 per cent 
solution of copper sulphate was used. The first and second trees 
recovered and the last one died. 
Buttner (9) treated 18-year-old Pinus monticola trees which had 
trunk infections. Attempts at cutting out the infections failed. 
He then applied "tree wax" to the visible infection itself and 20 cm. 
above and below it. The trees showed no blister rust in 1906. It 
would be interesting to learn if this held true for several years. 
Eriksson (33) recommends the use of tar to cover the infections 
and prevent the distribution of the spores. 
Tubeuf (164) says that valuable trees may be saved by cutting 
out infections and treating with lysol, asphalt, etc., if Ribes are 
removed for a distance of 50 meters, so that no new infection can 
occur. 
Kneiff (74) removed blisters by frequent wet rubbing. He also 
used "tree wax" and cloths wet with carbolineum. These hindered 
the disease, but he says the best way to fight it is the removal and 
burning of the diseased parts or plants. 
Pechon (105) advises burning affected trees and states that treat- 
ment with tar and similar substances will not suffice. 
Kohler (75) tried cutting out and smearing, but gave up these 
methods as causing too much injury and even death. He sprayed 
the trunks with a strong stream of water before the blisters opened 
in the spring. The blisters disappeared and the trees formed new 
bark. 
