4 BULLETIN 444_, U. S. DEPARTMENT OP AGRICULTUBE. 



ECONOMIC IMPORTANCE. 



This disease is an important factor in reducing the crop of cran- 

 berries in Wisconsin. In some bogs one-half of the crop may be lost 

 on this account, as affected vines rarely produce any good fruit. 

 Fortunately, in Massachusetts, New Jersey, and on the Pacific coast 

 the disease up to the present time is confined to very small areas. 

 It is very important, therefore, to avoid the introduction of diseased 

 vines in new plantings. 



CAUSE. 



At present the cause of this pathological condition is uncertain. 

 Careful examination and study of many specimens in the field and 

 laboratory have failed to give any evidence that insects or fungi 

 cause the trouble, and the writer has come to believe, from all the 

 evidence at present available, that it is primarily due to some serious 

 disturbance of the nutritive fimctions of the plant. Goebel (4) says: 

 "In like manner there can be no doubt that the phyUody of flowers, 

 a favorite domam of teratology, is a symptom of disease; it is a mis- 

 birth, the cause of which we do not know in most cases." Similar 

 effects, such as chloranthy, as Peyritsch (8) has shown, may be 

 induced by aphides. In other cases it may be assumed that the 

 power of producing reproductive organs has been enfeebled, whUe 

 the vegetative growth has been abnormally stimulated through the 

 nutritive conditions. 



Beijerinck (1 and 2) assumed the existence of certain growth 

 enzyms which caused the formation of normal organs. In case of 

 the transformation of organs, according to his theory, one growth 

 enzym must replace another or be formed instead of it. 



In the case of the cranberry it seems possible that this striking 

 metamorphy is due to some serious disturbance of the nutrition of the 

 plant. A similar opinion was also expressed by Jones and Shear (5) 

 as the result of a joint field study of the disease. Mr. Malde (6), 

 who has observed this trouble for many years in Wisconsin, says: 



The dryness of the season seems to have reduced the amount of "false blossom " this 

 year, and from the data gathered in the Mather region, it has become more evident than 

 ever that this so-called "false blossom " is due to conditions of culture rather than any 

 disease affecting the plant. 



In all the localities in Wisconsin in which the writer has observed 

 this malformation, there has been a deep, coarse, peat soil, suppHed 

 with an excessive amount of water during the greater part of the 

 growing season. Of course these peat bottoms contain vast quanti- 

 ties of nitrogenous matter, but not in such form as to be available to 

 ordinary farm crops. The cranberry, however, is regarded by physi- 

 ologists as obtaining its nutriment chiefly by means of the endophytic 

 mycorrhiza of its roots and may be able to secure an abundance of 



