6 BULLETIN 714, U. S. DEPARTMENT OF AGRICULTUEE. 



FUNGI. 



IMPORTANCE. 



The writers' observations (10) indicate that rot-producing fungi- 

 cause at least one-half of all the loss in cranberries after picking. 

 These fungi are, however, by no means of uniform importance in 

 difl'erent regions or in diiferent seasons. A study of a number of 

 neighboring bogs during a single yeav or of a single bog through a 

 series of years can not fail to impress the investigator with the ex- 

 treme variation in the loss due to decay. 



An illustration of the variation in the amount of rot over a con- 

 siderable area in different seasons is found in the annual reports of 

 the board of inspectors of the New England Cranberry Sales Co. for 

 the last five years, as given by the chairman, Mr. H. S. Griffith (6). 

 The crop of 1913 was described as " remarkably free from fungoas 

 disease"; in 1914 and in 1915 there was a large percentage of un- 

 sound fruit ; the crop for 1916 was unusually sound up to November 

 1, after which a noticeable, though not very serious, amount of end- 

 rot developed; the crop for 1917 was in general of good keeping 

 quality, with a small amount of fungous disease. As these inspectors 

 determine the brand of the crops from representative bogs over much 

 of the Massachusetts cranberry area, their reports, no doubt, repre- 

 sent fairly well the condition for the entire region. 



The prevalence of rot in some seasons seems to be associated with 

 weather conditions which would favor the growth and spread of 

 fungi. Our knowledge of these relations is too slight, however, to 

 permit of very definite conclusions. Diiferences in the amount of 

 rot on different bogs or on various portions of one bog are often 

 related either to lack of vigor or to excessive growth of the vines, 

 due to various causes. These relations will be considered later. 



PRINCIPAL CRANBERRY FUNGI WHICH CAUSE FRUIT ROTS. 



The fungi which cause the decay of cranberries after they are 

 picked are in a large part those which attack the fruit on the vines. 

 The molds which cause decay of such'perishable fruits as strawberries 

 and raspberries are rarely found on cranberries and are, therefore, 

 of slight importance. 



Among the diseases which are the principal causes of losses of 

 cranberries in storage are early-rot (8), caused by Guignardia vac- 

 cina Shear, which is also the cause of scald and blast, and which is 

 especially destructive to fruit on the vines and early in the season 

 in New Jersey; end-rot (9), caused hy Fusicoccumputrefaciens Shear ^ 

 common on fruit in storage, especially late in the season and in the 

 northern cranberry regions; bitter-rot, caused by Glomerella cingu- 

 lata vaccina Shear; ripe-rot, caused by Sporonema oxy cocci Shear; 

 and blotch-rot, caused by Acaidhorhg acliua vaccinii Shear. Soft-rot, 



