APPLE DISEASES 



443 



west this fungus found it a favorable host 

 on which to develop. Up to the present 

 time no one has yet determined what 

 this native host is, or at least no pub- 

 lished record has been made. 



Disease on Fniit 



The apple tree anthracnose is not un- 

 common as a rot of the fruit as shown 

 in Fig. 4. This may be developed in the 

 orchard, especially if the fruit is allowed 

 to hang late on the trees, or may be de- 

 veloped as a storage rot on fruit which is 

 perfectly sound when stored. 



Lawrence (1904) seems to be the first 

 to have recorded this disease as a rot on 

 the fruit. 



Gate (1908) also found the disease 

 common upon apple fruit and produced 

 the rot by Inoculation. In the season of 

 1911 this disease developed abundantly 

 and seriously as a rot on stored fruit 

 both under ordinary storage conditions 

 and in cold storage. The writer has seen 

 boxes of Spitzenburg apples kept in stor- 

 age until May in which 90 per cent of the 

 fruit was affected with this disease. The 

 disease seems to be more abundant on 

 the fruit, as would be expected, in seasons 

 of early fall rain or when, on account of 

 weather conditions, picking is delayed. 



The most obvious line of attack for the 

 control of this trouble on the fruit is to 

 control the disease in the orchard by 

 proper spraying methods. The disease 



has developed, however, is some cases, in 

 considerable percentage in orchards in 

 which anthracnose was not present or 

 present only in very slight amount, not 

 sufficiently to account for any large per- 

 centage of infected fruit. This has been 

 observed both in Hood River and the 

 Willamette valleys. This fact suggests 

 that a further study of the disease should 

 be made under these conditions in an 

 effort to determine the source of infec- 

 tion and whether or not the fungus may 

 occur under conditions not at present 

 well understood. 



Methods of Treatment 



As soon as the nature of the disease 

 and the nature of the life history of the 

 fungus causing it came to be understood 

 a method of treatment at once suggested 

 itself. Since the infection by the fungus 

 takes place in the fall and early winter, 

 after the fall rains begin, it is evident 

 that spraying in the summer and fall is 

 a logical method of attack, and this gen- 

 eral method has been recommended since 

 1S95. by Pierce, Cordley, Lawrence, and 

 those who have made a specialty of this 

 disease. Both lime-sulphur and Bordeaux 

 mixture have been used in the winter 

 strength for this purpose, though the evi- 

 dence is at the present time that Bor- 

 deaux mixture has given much more 

 uniform and satisfactory results. The 

 time of spraying has been difficult to 



Fig. 4. Anthracnose Rot on -\pples. 



