SUMMARY OF THE WHITE-PINE BLISTER RUST 

 SITUATION 1 



By Dr. Haven Metcalf 



At the Albany meeting of this committee approximately one year 

 ago, I stated, in summarizing the situation of that time, that we faced 

 essentially three problems rather than one, the problem being different 

 in three sections of the country, as follows : 



1. West of the Mississippi River. — In this territory the disease was 

 not known to occur, but was believed to have been carried in on nursery 

 stock of 5-needle pine or Ribes. No effective quarantine for this sec- 

 tion existed at that time. 



2. From the Mississippi River to the Hudson River. — In this terri- 

 tory advance infections had been successfully stamped out in Ohio and 

 Indiana. Serious local infections existed in Wisconsin and Minnesota, 

 particularly in the territory within 30 miles of St. Paul. The disease 

 was not known to be present in Michigan. It was known to exist scat- 

 teringly in western New York and Ontario, while the Niagara Penin- 

 sula in Ontario was seriously infected. Several infections, mostly in 

 nurseries, had been found in Pennsylvania and New Jersey. 



3. East of the Hudson River. — In this territory infection was gen- 

 eral, particularly on Ribes, and there was no hope of completely eradi- 

 cating the disease. 



At the present time our territorial division of the problem still holds 

 good. The States west of the Mississippi have been scouted; hundreds 

 of potentially dangerous shipments of nursery stock of both 5-needle 

 pines and Ribes have been found which will need to be watched for 

 many years. So far, however, the disease has been found at only four 

 points in the eastern part of this territory, namely, one nursery and one 

 small planting in Minnesota, one small planting in northwestern Iowa, 

 and one small planting in eastern South Dakota. None of these was 

 located in such a way as to be dangerous. 



Considerable attention has been attracted to the Cronartium on Ribes 

 in Colorado, which so strongly resembles Cronartium ribicola as to have 

 been assigned that name. Its Peridermium stage has not been known 



' Remarks at the close of tlic conference of the Committee on tlie SnpiJressiun 

 of Pine Blister Disease in North America, held at Pittsburgh, Pa., November u- 



13. 1917- 



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