B. P. I. 286. 



CRANBERRY DISEASES. 



INTRODUCTION. 



The American cranberry (Vaccinium macrocarpum) has been in 

 cultivation for seventy-five years or more. The wild plant in its 

 native habitat does not appear to be affected to any very noticeable 

 degree by fungous parasites. Up to the present time only five species 

 of fungi, according to the published host indices, have been reported 

 as occurring upon this plant. It is generally the case, however," that 

 the longer a plant is in cultivation and the greater the area covered 

 by it the more numerous and serious are its parasites, since the con- 

 ditions and opportunities for their development and distribution be- 

 come much more favorable. This is true of the cranberry. At the 

 same time, this plant by selection, cultivation, and growth under 

 rather abnormal conditions has apparently become somewhat weak- 

 ened and more susceptible to disease. 



The cranberry is distributed from Newfoundland southward 

 through the Alleghenies to North Carolina and westward into Wis- 

 consin. It is also cultivated in a few localities on the Pacific coast, 

 in Oregon and Washington. The native cranberry of that region is 

 regarded by some botanists as a variety of Vaccinium oxy coccus.' 1 () 



The diseases of the cranberry are most serious in the southern sec- 

 tions of its area of cultivation. The losses from the various maladies 

 are heaviest in New Jersey and decrease as one proceeds northward 

 through Long Island, Connecticut, and Massachusetts, being least of 

 all in. the bogs of Nova Scotia. There is also comparatively small 

 loss from disease at present in Wisconsin and on the Pacific coast. 

 The annual crop of the United States approximates 1,000,000 bushels, 

 valued at about $2,000,000. The loss from disease is estimated to 

 average about 10 per cent, or $200,000 each year. From a careful 

 study of the matter is seems probable that the climatic conditions are 

 chiefly responsible for the greater amount of loss in the southern 

 localities. The long, hot summers of the southern region seem to 

 be unfavorable to the production of the most hardy cranberry plants 



o The serial numbers used in this paper refer to the bibliography which will be 

 found on pages 55 to 57. 



3525 No. 11007 M 2 



9 



