CHESTNUT BARK DISEASE. 445 



like to know if the blight on the whole, without regard to 

 treatment in checking it, has spread as seriously in Pennsylvania 

 during the past year as it did in 1911. So far as Connecticut 

 is concerned, there seems to be a decided improvement, if we 

 can judge by the reports that we have received." 



In answer to this letter, under date of March I, 1913, Carle- 

 ton wrote as follows : "I have your letter of February 28th, and 

 in reply will say first, that the reports in the papers about the 

 spraying with Bordeaux mixture in connection with chestnut 

 blight were, as usual, much exaggerated, and in some respects 

 quite erroneous. The use of Bordeaux mixture is, at most, 

 only a preventive, though the papers reported it to be a cure. 

 Of course, as you know, nothing will cure the disease after it 

 is in the tree. The Bordeaux was used on the estate of Pierre 

 DuPont near Kennett Square. In connection with tree surgery 

 methods, and by spraying about every two weeks during the 

 summer, these two methods taken together appear to have con- 

 trolled the blight. It is believed that the Bordeaux mixture was 

 of great use in preventing the germination of spores on healthy 

 trees, and on healthy portions of trees that were being treated. 

 I believe the spraying with Bordeaux is of sufficient importance 

 in chestnut orchards to recommend its practice in all cases of 

 chestnut blight. It might be used, also, on unusually valuable 

 lawn trees, but of course, it would be impracticable in forest 

 tracts, chiefly on account of the cost, and for other reasons. 



"As to the spread of the blight in Pennsylvania, I regret to 

 say that over a large portion of the state it has apparently 

 spread more rapidly than the year before, so that the conditions 

 appear, therefore, to be different from those in Connecticut, 

 according to your statement. Because of the condition last 

 stated, of the serious increase of the disease in this state, and 

 particularly in those portions west of the Susqtfehanna, where 

 we are endeavoring to check its progress, you can see that our 

 work has been unusually difficult. Answering your question, 

 however, as to our success in actually checking the blight, so far 

 as we can get evidence one way or the other at all in the short 

 time that I have been in the state, I believe we have accom- 

 plished a great deal in that line. We can only actually know 

 next summer, when we re-scout the areas over which cutting 

 was done this summer. So far, in the areas of removal which 



