70 



AMERICAN FORESTRY 



TREE AT SWANSEA, MASSACHUSETTS 



This white pine tree in native growth is about 30 feet high and shows the 

 main stem girdled near the top. S. B. Detwiler, U. S. Forest Inspector, 

 is making the examination. 



THIS WAS DESTROYED 



A fine white pine of native growth near Ipswich, Massachusetts, which 

 showed so many pine blister cankers on the branches that it was marked 

 for destruction before the spores which would have developed this year 

 and spread the disease appeared. 



It is certain that the blis- 

 ter disease cannot pass from 

 pine to pine without pass- 

 ing through the intermediate 

 stage on currant or goose- 

 berry leaves. Therefore, the 

 only question that can arise 

 concerning the effectiveness 

 of the proposed method of 

 controlling the disease is 

 whether it is possible to de- 

 stroy all the currants and 

 gooseberries on a given area 

 and thereafter keep it free, 

 and whether the value of the 

 pine will justify the cost of 

 the work. Further experience 

 in eradicating currant and 

 gooseberry bushes on a large 

 scale will undoubtedly 

 develop cheaper and more 

 effective methods, as for 

 instance, killing strongly- 

 rooted bushes or mats of skunk 

 currants by means of chem- 

 icals sprayed on the leaves. 

 The destruction of the dis- 

 eased pines is an additional 



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i COOPERATION BY CITIZENS REQUIRED I 



IN FIGHTING THE PINE BLISTER 



DISEASE 



Federal and State action, to be successful, re- j 



| quires the active cooperation of individual citizens | 

 I in the following particulars : 



1. When the disease is found on pines, currants j 

 | or gooseberries, the State officials in charge of j 

 | control work should be notified, and the diseased [ 

 | plants destroyed promptly, according to the | 

 I recommendations of the authorities. 



2. Where State authorities deem it necessary 



I to destroy all currant and gooseberry bushes, or j 



I take other drastic action to control the disease, [ 



| individuals should give all possible aid and influ- I 

 j ence others to do so. 



3. The general planting of five-leaved pines j 



[ should not be encouraged. The growing of cur- j 



| rant or gooseberry stock should not be favored in j 



1 localities where they may endanger white pines, j 



| In the case of white pine planting stock, the ! 

 I nursery from which it is purchased should be 



I required to give a written guarantee that the ! 



| stock was grown from seed in their own nurseries, I 

 | that no infections of the white-pine blister disease 



I have ever been found in the nursery or within | 



| 500 yards, and that the trees have not stood near j 

 | currant or gooseberry bushes. 



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precautionary measure that 

 appears advisable in large 

 control areas to prevent 

 the disease being carried to 

 currants and gooseberries be- 

 yond the borders of the area. 



When small spots of infec- 

 tion exist beyond the region 

 of generally scattered disease, 

 it will usually be advisable 

 to destroy both pine and cur- 

 rant hosts known or suspected 

 as having been exposed to 

 infection, and the greatest 

 sanitary precautions taken, 

 such as sterilizing the uni- 

 form of inspectors, and dis- 

 infecting the plants having 

 fruiting bodies of the fungus 

 before they are handled, 

 during such time as the 

 spores are visible. 



At the present time, the 

 legal and financial barriers 

 standing in the way of con- 

 trolling the disease appear 

 even greater than the prac- 

 tical difficulties. It will con- 



