Recent Studies on Peach Yellows and Little Peach 49 



increased at a rapid rate, with relatively few cases of yellows. In 

 1919, one tree was infected with both diseases, each on a different 

 part of the tree. 



For the first six years in the life in the orchard the loss was rela- 

 tively small, amounting to a total loss of 16 trees, or about 3 per cent 

 of the original planting. In the seventh year (1913) there was an 

 increase in the annual loss, when it rose to 1.63 per cent. The suc- 

 ceeding two years witnessed a decline, but beginning with 1916 an 

 increased loss occurred again. From that year, with a loss of 1.48 

 per cent, the diseases spread and the losses increased gradually until 

 1919. In 1920 more trees became diseased than the total for the 

 preceding 13 years. 



The data for orchard no. 2 are given in table 3. This orchard 

 consisted of 28 rows of 16 trees each, separated by a roadway from 

 and located west of orchard no. 1 and of 6 rows of 17 trees each 

 adjoining orchard no. 1 on the northeast ; in the latter section the 

 trees and rows are lettered instead of numbered. This orchard was 

 planted in 1908, and the two sections consist of a total of 550 trees, 

 mainly of the variety Elberta. 



As in orchard no. 1, the predominating disease was little peach; 

 in only one year (1912) were there more cases of yellows than of 

 little peach. Likewise, the first case of the disease occurred in the 



Table 4 



Peach Yellows and Little Peach Loss from Orchard No. 3, Vineland 



496 Trees, Planted 1912 



Year 



Little 

 Peach 



Yellows 



Both 



Total 



Per cent 

 Lost 



third year of the life of the orchard. However, in this orchard, the 

 diseases increased gradually and at a more rapid rate than in no. 1 

 up to 1915. In 1916 there was a decrease in infestation, correspond- 

 ing to the decrease in orchard no. 1 in the year 1915, the corre- 



