APPLE DISEASES 21 
operations should be performed in the winter since the cankers 
are not only more easily located when the leaves are off, but 
such work should be done before the conidia are disseminated 
in the summer. 
Spraying has proved effective, 90 per cent bitter-rot-free fruit 
being a possibility. Dormant spraying is said to have no value. 
Spray at least once before the buds open; make a second appli- 
cation by the middle of June. Succeeding applications must 
be made at intervals governed by the weather. Bordeaux 
mixture, 44-50, should be used; lime-sulfur is not effective. 
REFERENCES 
Schrenk, H. von, and Spaulding, P. The bitter rot of apples. U.S. 
Agr. Dept. Plant Indus. Bur. Bul. 44: 1-54. 1903. (Extended 
bibliography.) 
Roberts, J. W. Sources of the early infections of pple bitter rot. 
Journ. Agr. Research 4: 59-64. 1915. 
Scott, W. M. The control of apple bitter rot. U.S. Agr. Dept. Plant 
Indus. Bur. Bul. 93: 1-36. 1906. 
Burrill, T. J. Bitter rot of apples. Botanical investigations. Illinois 
Agr. Exp. Sta. Bul. 118: 554-608. 1907. 
Blair, J. C. Bitter rot of apples. Horticultural investigations. 
Illinois Agr. Exp. Sta. Bul. 117: 482-551. 1907. 
Alwood, W. B. The bitter rot of apples. Virginia Agr. Exp. Sta. 
Bul. 142: 252-279. 1902. 
Frre-B.icHT 
Caused by Bacillus amylovorus (Burr.) Trev. 
The apple and the wild crab are commonly attacked by fire- 
blight. In the nursery these forms are more seriously affected 
than pears. In the young orchard the disease is also injurious, 
but old bearing trees do not suffer materially. It is true that 
the latter class of trees frequently show a large amount of twig- 
blight, yet the financial loss from such an affectation is negli- 
gible. While no variety is wholly immune, there is an apparent 
