APPLE DISEASES 13 
the fourth applications. Bordeaux mixture has been used 
widely for the control of apple diseases, and particularly for 
scab. It has been replaced with lime-sulfur spray and a sulfur- 
lead dust on account of the injury or russeting of fruit which 
results from the use of bordeaux (Fig. 124, page 434). 
It has been shown that dusting with properly powdered 
materials is fully as effective as spraying. The operation is 
much more rapid in covering the orchard; an orchard may be 
dusted in one-fifth to one-tenth the time required for spraying 
the same. This dusting process not only saves time but an 
orchard of large acreage may be protected at critical times, a 
thing not always possible with the slower liquid process. ~ Apply 
a mixture of ninety parts finely powdered sulfur and ten 
parts arsenate of lead (powdered), using about one and one- 
fourth to two and one-half pounds a tree at each application. 
The smaller dusting machines may be operated by hand, the 
larger ones by a gasoline engine. The time of application of 
dust mixtures does not differ from that of the application of 
sprays. 
REFERENCES 
Wallace, E. The scab disease of apples. Cornell Univ. Agr. Exp. _ 
Sta. Bul. 335 : 545-624. 19138. i 
Clinton, G. P. Apple scab. Illinois Agr: Exp. Sta. Bul. 67 : 109-156. 
1901. ‘ 
Reddick, D., and Crosby, C. R. Dusting and spraying experiments 
with apples. Cornell Univ. Agr. Exp. Sta. Bul. 369: 308-356. 
1916. 
Jackson, H. S. Diseases of pomaceous fruits. Scab. Oregon Crop 
Pest and Hort. Bienn. rept. 1911-1912 : 238-241. 1913. 
Whetzel, H. H., and Hesler, Lex R. Some of our most common apple 
diseases. ‘Apple scab. In The Fruit Industry in New York State. 
New York Agr. Dept. Bul. 79: 855-861. 1916. 
Aderhold, R. Die Fusicladien unserer Obstbiume. Landw. Jahrb. 
25: 875-914. 1896. 
Aderhold, R. Die Perithecienform von Fusicladium dendriticum 
(Venturia chlorospora f. Mali). Deut. bot. Ges, Ber. 12: 338- 
342. 1894. : 
