B. P. I.— 198. V. P. 1'. I.— 149. 



TH1-: CONTROL OF .II'PLI'^ BITTER-ROT. 



INTRODUCTION. 



Accounts of severe losses of the {i])ple crop of the United States 

 caused by l)itter-rot {Glomerelhi I'lifomaeuldiis (Berk.) Sptuddino- & 

 von Schrenk) date back to 1870, and since that time destructive out- 

 breaks of this disease have occurred at frequent intervals with appar- 

 ently increasing severit}' until a loss of several million dollars in a 

 single season is not uncommon. An epidemic occurred in 1900, when 

 it was estimated that the damage to the apple crop of the United States 

 was $10,000,000/' and in 1902 the attacks of the fungus were again 

 exceedinolv severe. 



Although the fungus c-ausing this disease occurs in nearly every 

 apple-growing State in the eastern part of the United States, severe 

 losses from it have been confined to the southern half of the apple belt, 

 Missouri, Illinois, Arkansas, Virginia, West Virginia, and Kentucky 

 suffering especially in recent years. 



This disease has had the attention of the Department of Agriculture 

 for a number of 3'^ears. In the Report of the Chief of the Section of 

 Vegetable Pathology for 1887'' appeared the first economic discussion 

 of the disease by an American writer, followed in 1891 '' hy sl more 

 extensive account of the fung-us bv Miss E. A. Southworth. In 1903 

 Messrs. von Schrenk and Spaulding,'' of the Mississippi Valle}' Labora- 

 tory of the Bureau, published a general account of the bitter-rot dis- 

 ease with a description and life histor}^ of the fungus causing it. 



In 1903 the attention of the Bureau of Plant Industry was called to 

 an outbreak in Virginia and West Virginia, and the writer was detailed 

 to investigate the trouble and ' arrange for remedial experiments. 

 During the months of August and September (1903) a number of 

 orchards in each of these States were visited, and it was found that, 

 although several other good varieties were affected, the highly prized 

 Yellow Newtown (also known as Albemarle Pippin) was, as usual, the 

 greatest sufferer. In some cases the destruction was complete, and to 



« Woods, A. F. Annual Reports, Department of Agriculture, 1901, p. 47. 



& Annual Report of the Commissioner of Agriculture, 1887, pp. 348-350, PI. III. 



c Journal of Mycology, VI, pp. 164-173, PL XVI. 



ci Bui. 44, Bureau of Plant Industry, U. S. Department of Agriculture, 1903. 



7 



