Report of State Board of Horticulture. 99 



the winter stage which may be found later upon the fallen 

 leaves ; while similar conditions in spring provide equally fav- 

 orable conditions for its spread upon the young leaves, blos- 

 soms iind fruit. 



No extensive discussion of the disease is necessary at this 

 time. Suffice to say that it appears first in spring upon the 

 young leaves even before the blossoms appear. It also ap- 

 pears on the blossoms and may so seriously injure the young- 

 fruit as to cause much of it to drop; or cause such blotches 

 upon the mature fruit as to make it worthless for market 

 purposes. In cases of serious infestation the disease so in- 

 jures the leaves that the trees may become nearly defoliated 

 in September or October, thus cutting off the nourishment 

 which should go to developing fruit buds. 



The accompanying illustrations will serve to show the 

 nature of these injuries to leaf and fruit. 



The disease can, however, be very satisfactorily controlled 

 by spring spraying with bordeaux mixture. In the spring of 

 1903, experiments in spraying for this disease were con- 

 ducted in an orchard of Newtown Pippin trees. This partic- 

 ular block of trees was selected, first, because the Newtown 

 Pippin is one of the varieties most susceptible to apple scab 

 in the Willamette Valley; second, because the orchard has 

 been neglected for years. It is now about fifteen years old, 

 has never been thoroughly cultivated, and has been sprayed 

 but two seasons, during one of which it received but one 

 application. 



The orchard was sprayed five times the past season, with 

 the 4-4-50 bordeaux, viz., on April 30, May 14 to 19, June 1 

 to 3, July 1 to 3, and August 15. The last two applications 

 were made more particularly for the codling moth, only the 

 poison being used. These applications no doubt were prac- 

 tically of no value as a preventive of scab, only the first 

 three being of any benefit. The climatic conditions were par- 

 ticularly favorable to the development of the scab. This was 

 particularly true during the time of the second spraying. 

 May 14 to 19, when the showers were almost continuous. 

 Thus the application which should have done more good than 

 any other was made under very adverse circumstances, being 



