U S. EXPERIMENT STATION BULLETINS. 



405 



Table II. — Shoioing cases of peach yellows by years on treated and untreated plats in 

 orchard of James W. Green, Magnolia, Delaware. 



When these treatments began, over 90 per cent, of the trees were healthy, 

 thrifty, and fair to look upon. There were quite a good many cases of 

 yellows in the orchard in 1887 and more in 1888, and it was feared that 

 the whole orchard would finally succumb if something were not done. 

 This particular spot in the orchard was selected because the soil appeared 

 to be uniform, and because the trees had made a uniform growth, and 

 were in a great measure free from signs of disease. With the exception 

 of one row of Christiana on the west side, and one row of Oldmixon on 

 the east side, the trees were all of one variety — Crawford's Late. The 

 difference in variety appears to have exerted no influence upon the results. 

 The cases were determined each autumn, and the fertilzers were applied 

 each spring, beginning with the year 1889. In 1889 and 1890 they were 

 harrowed in. In 1891 they were plowed down three to five inches. 



The plats were selected in an orchard where there were several hundred 

 cases of yellows, and in a neighborhood where the disease had been on the 

 increase for several years. When the treatments began, absolutely noth- 

 ing certain could be predicted as to the course of the disease, but the 

 presumption was strong that an excellent location had been selected for 

 testing the virtues of muriate of potash, dissolved bone black, and kieserite. 



When the treatment began, as you will see from the diagram, there 

 were four cases on A, four on B, three on C, and ten on D, making a total 

 of twenty-one out of 240 on the treated plats. In the plat of 100 trees 

 held for comparison, there were five cases. Exclusive of D, which had 

 twice as many cases to start with, the per cent, of cases on the control and 

 on the treated areas, was almost identical, i. e. five per cent, and six per 

 cent. 



