THE white-pine: buster RUST SITUATION 87 



The disease has been found at three points in Pennsylvania on pine and 

 eradicated so far as found. It has never been found on Ribes in Penn- 

 sylvania. In New Jersey the disease has been found at two points and 

 eradicated. Scouting to the south of Pennsylvania as far as Alabama 

 has revealed no case of the disease. 



Perhaps the most dangerous element of the situation in this area is 

 the generally infected condition of Ontario. Not only is the Niagara 

 Peninsula generally infected, but the disease is apparently present on 

 Ribes, at least quite generally throughout Ontario. It is evident that 

 from Ontario the disease can spread naturally into Michigan, and it is 

 possible that it can continue to spread north of the Great Lakes until it 

 infects the white-pine belt of Wisconsin, Minnesota, and Manitoba. 



East of the Hudson River the situation could hardly be worse. In- 

 fection of Ribes is general, and this, of course, means that infection on 

 pine is also general, although at present apparently only at scattered 

 points. Massachusetts, particularly, is most seriously infected. It is 

 evident that in this territory the only hope for the future growing of 

 white pine lies in local control by the eradication of Ribes. In places 

 where it is financially possible and otherwise practicable to destroy 

 Ribes the white pine can be grown. In other places it may be expected 

 that its culture will have to be given up. The figures presented at this 

 meeting on the cost of Ribes eradication seem to favor the idea that 

 there are many localities where such control will be financially possible, 

 and this view is also favored by the continual increase in the value of 

 white-pine stumpage. 



In summing up the situation, we have certain aspects of the case 

 which may be regarded as favorable for the control of the disease. 

 These may be enumerated briefly as follows : 



1. The essential freedom of the Western States from the disease. 



2. The fact that two large areas in Minnesota, one in Wisconsin, one 

 in New York, and several small areas in Pennsylvania, Ohio, and 

 Indiana have been ap])arently freed from the disease. 



3. The fact that the infections found in the middle territory this 

 season are old and not infections which have gotten loose since control 

 measures were inaugurated. 



4. Further research also substantiates the idea that the progress of 

 the disease is slow — that is, slow compared to the jirogress of a disca.se 

 which has no alternate host. The much-.studied infection at Kittery 

 Point, Maine, is apparently 15 years old, and yet the number of trees 

 infected within the entire eradication of 3 .square miles does not at the 

 present time api)ari-iUly exceed 10 pc-r cent of the wlioK' ininih(.'r, 



