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 strohus 

 trees with 10 per cent and 20 per cent solutions of carbolineuin. 

 This was applied Math a brush on April 28, 1908, be'fore 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. 



Biittner (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 b}" 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. 



Koliler (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. 



