THE WHITE-PINE BLISTER RUST. 



pines, or other 5-needle pines l that were imported from Europe are 

 liable to have the disease. 



Therefore, at any time of year 



(1) Find out definitely the source of your pines. Were they raised from seed in this 

 country or bought of some one who might have imported them? Get a definite state- 

 ment from the man who furnished them to 



you. If he obtained them from another per- 

 son, find out from the latter whether he raised 

 them from seed or not. In short, trace your 

 trees definitely back to the nursery where they 

 were grown from seed. Do not accept an eva- 

 sive reply. If the source of your pines can 

 not be determined or if they prove to have 

 been imported, consider them under suspicion 

 until you can have an expert inspection made. 

 The Bureau of Plant Industry, on application 

 embodying a statement of such facts as are 

 known to the owner or observer, will make an 

 inspection or secure a competent inspection 

 free of charge. 



(2) Inform your neighbors about this dis- 

 ease. Find out whether their pines were 

 grown in America or imported. Tell themif 

 you think you see evidences of the blister rust 

 on their trees, and advise them what to do. 

 Diseased trees on your neighbor's land are a 

 source of danger to you. Post this publica- 

 tion in a conspicuous place, such as the rail- 

 road station, post office, town hall, and grange 

 hall. Tell your neighbors to ask the United 

 States Department of Agriculture for Farmers' 

 Bulletin 742, if the disease is on their trees or 

 they are interested in it. Secure more copies 

 yourself if they can be well distributed. 



(3) If you can not prove that your pines 

 were grown in America from seed, look at all 

 times of the year for dead trees, dead tops, or 

 dead side branches on the pines. If any are 

 found, look for a girdle of dead, cracked bark 

 below the dead part, as shown in figures 1 

 and 2. If a girdle is found, look for the pyc- 

 nidial drops on the living swollen bark ad- 

 joining the dead portion. (See fig. 3, showing them on a tree not yet girdled.) 



1 The scientific and popular names of the 5-needle pines of the world, exclusive of the different varieties, 

 are here given for the convenience of nurserymen and others who may wish definite technical information: 

 AMERICAN. Pinus strobus, white pine; P. monticola, western white pine; P. lambertiana, sugar pine; 

 P. flexilis, limber pine; P. albicaulis, white-bark pine; P. strobiformis, Mexican white pine; P. balfouriana, 

 foxtail pine; P. aristata, bristle-cone pine; P. cembroides, pinon pine. FOREIGN. Pinus cx'celsa, Hima- 

 layan white pine; P. pence, Balkan pine; P. armandi, Chinese white pine; P. parviflora, Japanese white 

 pine; P. ccmbra, stone pine; P. koriensis, Korean pine. Some of the more important varieties which are 

 included In the foregoing species are Pinus nepalensis, P. scipioniformis, P. mastersiana , P. pentaphylla, 

 P, morrisonicola, P.formosana, P. pumila, P. mandschurica , P. sibirica, and P. coronans. 



FIG. 3. A young white-pine tree, showing 

 the swelling and pycnidial drops of liquid 

 caused by blister rust. (Life size.) 



