Recent Studies on Peach Yellows and Little Peach 1 1 



In a yellows and little peach district a loss of 1 per cent of the 

 trees annually is low even during what might be called a quiescent 

 period between epidemics, while a loss of from 2 to 3 per cent by in- 

 fection per year is common. During so-called epidemics the per- 

 centages may increase to 25 per cent even in orchards where the dis- 

 eased trees are removed annually, as was the case at Vineland, re- 

 ported later on pages 46 to 53. 



The United States Census for 1910 reports 15,508,921 bearing and 

 non-bearing trees for New York, New Jersey, Pennsylvania, Dela- 

 ware and Maryland. An ordinary loss of 3 per cent for this terri- 

 tory would amount to 450,000 trees annually. The same report 

 places the number of bearing and non-bearing trees for New Jersey 

 at 2,580,108. A 3 per cent loss would mean 75,000 trees per year in 

 this state alone. 



A survey by the department of horticulture of the New Jersey 

 Agricultural Experiment Station in 1913 showed a total of more than 

 109,000 peach trees within a radius of 5 miles of Vineland, N. J. The 

 losses in the experimental orchards exceeded 20 per cent in 1920. 

 One can thus judge the extent of damage which these peach diseases 

 may cause in a local peach center. 



New Jersey Investigations 



An extensive study of the problems connected with commercial 

 peach production in New Jersey was begun by the State Experiment 

 Station in 1905 in an effort to assist in the revival of the industry 

 following the ravages caused by the San Jose scale. 



Experimental orchards were planted at High Bridge and Vine- 

 land, N. J., in 1906, 1907, 1908 and 1912. The principal features of 

 these experiments as first planned were the fertilizer treatments, and 

 it was early decided to keep a complete record of the yield of each 

 tree under test. This led to close observations of many hundred in- 

 dividual trees of various varieties from several sources, and under 

 many treatments. 



A few trees in these orchards failed to grow as well as others and 

 developed advanced and unmistakable symptoms of yellows and little 

 peach within three years of the time of planting. Therefore, it was 

 deemed wise to keep an accurate account and record of the individual 

 trees which became diseased from year to year. This was done in 

 the case of each orchard. The results are shown in the colored 

 diagrams following page 32. 



