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 clone 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, 4-4-50, 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. Bui. 44 : 1-54. 1903. (Extended 



bibliography.) 

 Roberts, J. W. Sources of the early infections of apple 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. Bui. 93 : 1-36. 1906. 

 Burrill, T. J. Bitter rot of apples. Botanical investigations. Illinois 



Agr. Exp. Sta. Bui. 118 : 554-608. 1907. 

 Blair, J. C. Bitter rot of apples. Horticultural investigations. 



Illinois Agr. Exp. Sta. Bui. 117 : 482-551. 1907. 

 Alwood, W. B. The bitter rot of apples. Virginia Agr. Exp. Sta. 



Bui. 142 : 252-279. 1902. 



FIRE-BLIGHT 

 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 



