New York Agricultural Experiment Station. 379 



and also tobacco. Joues reports ^^ that the Bordeaux mixture as 

 used against the blights prevents to some extent the attacks of this 

 insect. Figure 3 illustrates the work of this insect on the potato 

 leaf which may be compared with the healthy leaf sprayed with 

 Bordeaux mixture illustrated in Fig. 4. For figures 3 and 4 we are 

 indebted to Prof. Jones. 



3. Common Diseases and Insects Injurious to Nursery Stock. 



Apple. 



Powdery Mildew. — Powdery mildew is seldom very injurious 

 to apple stock in this locality. It attacks the leaves and young 

 twigs, where it appears as a light powdery substance. When it is 

 severe the seedlings may receive a serious check by the loss of foliage 

 and the killing back of the young shoots. It usually makes its ap- 

 pearance in the latter part of September. It is suggested that treat- 

 ment be given, using Bordeaux mixture 1 to 11 formula, beginning 

 in the fore part of September and repeating at intervals of about 

 two weeks until two or three sprayings have been given. 



Aphis. — Either the green aphis or the woolly aphis may be treated 

 as directed for cherry aphis below. • 



Bud Moth. — In the nursery this insect is sometimes fought by 

 pinching the infested leaves and thus killing the insect. Spraying 

 early in the spring, the same as for the same insect in the orchard, 

 is also suggested. 



Cherry. 



Leaf Blight. — The so-called leaf blight, or shot hole fungus, that 

 has been described as being particularly destructive to plum and 

 cherry trees in the orchard, often causes great damage in the nur- 

 sery. The injury is due to the loss of foliage ; the energy of the 

 tree is exhausted in its effort to produce new leaves, so its growth is 

 impeded or remains nearly or quite at a standstill. 



Remedy. — Expenments conducted at this Station^'' show clearly 

 favorable results from treatment with Bordeaux mixture, 1 to 11 

 formula. The number of treatments necessary to secure the best 

 results have not been fully determined. Bordeaux mixture is pref- 

 erable to any other remedy that has been tried for this trouble. It 

 is suggested that three or four treatments be given, especially to 



13 Bulletin 40 Vt. Expt. Station : 25 ; Bui. 41, : 93--97. 



14 See Annual Report, 1892 : C54 ; 1893 : 688. 



