THE PINE BLISTER DISEASE 



749 



realization of its danger came, and now the chestnuts 

 are practically wiped out. It is not intended to permit the 

 pine blister disease to get beyond control if it can be 

 helped, and that is the reason why the American Forestry 

 Association and others interested are determined to insti- 

 tute a vigorous and aggressive fight against it with the 

 least possible delay. 



Many questions regarding the blister canker are asked, 

 and the most inijiortant among them may well be answered 

 in the following paragraphs : 



The disease is now located in practically all of New 

 England, in areas of a number of square miles each in 

 New York at Essex, along the lower New York-X'ermont 

 border, and the New York-Massachusetts border, and at 

 Tarrytown. 'i'here is an area of a numljer of square 

 miles located on the Alinnesota-Wisconsin border, east 

 of St. Paul and extending roughly from the vicinity 

 of Hudson, Wisconsin to Tavlors Ealls, Minnesota. 



These are known outbreaks of the disease. The disease 

 has been located in two or three nurseries in New Jersey 

 and Pennsylvania, but so far as is now known there is 

 no outbreak of the disease within these States. 



As to the damage already done by the disease, it is 

 very difficult to state because up to this year most of the 

 outbreaks of the disease have been wholly or largely eradi- 

 cated as soon as found, so that the disease has been imme- 

 diately stopped at the time of finding it. This year, 

 however, a considerable number of serious outI)reaks, 

 previously unknown, have been discovered. The one which 

 probably will give a better idea of what this disease means 

 to this country than any other is located in southwestern 

 Alaine. Here accurate counts have shown on quarter 

 acre plots that 85 per cent of the total stand was diseased. 

 Of the infected trees about 50 

 per cent were already dead or 

 were girdled on the trunk so 





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WHITE PINE BLISTER DISEASE I\ XEW ENGLAND 



The pyramids indicate outbreaks of the infection on native white pine. The 

 squares indicate where infected white pine, currants and gooseberries have been 

 found in nurseries. Thedots indicate areas of infected pines, currants and goose- 

 berries. 



that they are doomed within 

 the next few years. There are 

 a number of cases somewhat 

 similar to this. 



As to the rapidity with 

 which the disease spreads 

 every outbreak located up to 

 the present time where pines 

 are seriously infected shows 

 that the disease has 

 been present in 

 those localities for 

 a number of years. 

 E.xperts are of the 

 opinion that the 

 weather conditions 

 in early summer c|uite largely 

 control the spread of this dis- 

 ease upon currants and goose- 

 berries, upon which its great 

 and rapid spread is apparently 

 made. There is evidence that 

 it may spread a number of 



., ' .... INFECTED WHITE PINE 



miles withm a vear. ^ .... 



' _ _ ^ Ihe bhster is here seen in a fruiting 



The advisability of cutting condition with myriads of spores to 



•^ ^ infect the foliage of currants and 



the afi^ected tree at once or of gooseberries. 



cutting off affected branches is much discussed. Experts 



