!8( 



2«0 



Bulletin 145. 



able conditions as readily to hold the mastery. This is authen- 

 ticated by my observations on older stock, which seems to be less 



affected when the culture 

 has been well attended to. 

 Nevertheless, the spot is 

 abundant on certain vari- 

 eties in spite of any culture 

 which I have seen. 



Extensive notes have 

 been taken as to the extent 

 of injury among the dif- 

 ferent varieties, but there 

 is so much variation that 

 no definite statement 

 should be made at present. 

 Certainly, however, thus 

 far Anjou, Seckel, Shel- 

 don, Summer Doyenne, 

 Dana's Hovey, Frederick 

 Clapp, and Bartlett have 

 shown the greatest injury, 

 somewhat in the order 

 named; Duchess very 

 slightly affected, with 

 Kieffer quite free; and all 

 of the remaining varieties 

 ordinarily grown suffer 

 more or less. 



Spraying experiments on 

 rather old nursery stock 

 were also begun at Cayuga, but through an unfortunate misunder- 

 standing most of the stock was removed after the second spraying, 

 and the only result of interest is the comparison between a few 

 Seckels and Anjous, sprayed late with Bordeaux and ammoniacal 

 copper carbonate respectively. Figures 161 and 162 indicate these 

 comparisons. 



162. — Sprayed ivith ammoniacal copper carbonate. 



