350 MANUAL OF FRUIT DISEASES 



added to the above, at the rate of 3 pounds to 50 gallons, to 

 increase the adhesiveness of the fungicide. The first applica- 

 tion should be made soon after the first leaves develop. There 

 should be four or five applications subsequent to the first, 

 depending upon the season. In seasons with only moderate 

 rainfall an application should be made once in every three 

 weeks. 



REFERENCES 



Galloway, B. T. Leaf-blight and cracking of the pear. U. S. Agr. 



Comm. Kept. 1888 : 357-364. 1889. 

 Duggar, B. M. Some important pear diseases, II. Leaf blight. 



Cornell Univ. Agr. Exp. Sta. Bui. 145 : 611-615. 1898. 

 Barrus, M. F. Diseases of pear. Leaf blight. In The Fruit Industry 



in New York State. New York Agr. Dept. Bui. 79 : 1050-1051. 



1916. 

 Kinney, L. F. The leaf blight of the pear. Rhode Island Agr. Exp. 



Sta. Bui. 27 : 3-7. 1894. 

 Kinney, L. F. The leaf blight and cracking of the pear. Rhode Island 



Agr. Exp. Sta. Rept. 1894 : 189-192. 1895. 

 Waite, M. B. Treatment of pear leaf-blight in the orchard. Journ. 



Myc. 7 : 333-338. 1894. 

 McAlpine, D. Leaf scald or fruit spot. Victoria Agr. Dept. Journ. 9 : 



512-515. 1911. 

 (See additional references under Quince, page 390.) 



OZONIUM ROOT-ROT 

 Caused by Ozonium omnivorum Shear 



This root disease is confined to the South and Southwest, 

 having been found particularly in Texas and New Mexico. 

 Pears are frequently injured to a very appreciable extent. 

 Affected trees usually show, on the roots, threads of the causal 

 fungus, Ozonium omnivorum; these threads are at first whitish, 

 then dirty- white or brown. Pear-trees in close proximity to 

 affected cotton, which also is affected by this disease, are most 

 liable to infection. It is believed that a tree once diseased 

 cannot be saved. (See under Apple, page 146.) 



