PREFACE. 



For the past four or five years the bitter rot of apples has been the 

 cause of heavy loss to growers and handlers of this fruit. As stated 

 in our report for 1901, the president of the National Apple Shippers' 

 Association estimated that the damage to the apple crop of the United 

 States in 1900 from bitter rot was $10,000,000. In some orchards 

 there was a total loss of fruit; in others from one-half to two-thirds 

 of the crop was destroyed. The disease is especially severe in the 

 Mississippi Valley and the States along the Ohio River. At the 

 request of numerous growers this Bureau undertook extensive inves- 

 tigations to determine more definitely the life history of the fungus 

 causing bitter rot with the hope of discovering a more effective method 

 of holding it in check. The report presented herewith contains a 

 general account of the history of the disease, a description and life 

 history of the fungus causing it, and some facts which have been 

 recently discovered in regard to the mode of life of the parasite. 



During the year 1901 cooperative experiments, conducted along lines 

 suggested by this Bureau, were carried on with the Illinois Experi- 

 ment Station, but during the last season the work was conducted inde- 

 pendently by both the station and the Department, Cooperative 

 experiments on the control of this disease were started the past year 

 with the Missouri Fruit Experiment Station, and will be continued 

 with this station and fruit growers in various apple sections during 

 the present season. 



Albert F. Woods, 

 Pathologist and Physiologist. 



Office of the Pathologist and Physiologist, 



Washington, D. C, April 7, 1903. 



