4: BULLETIN 1U, U. S. DEPARTMENT OF AGRICULTTJEE. 



the Early Black and tlie Howe varieties were kept in containers of 

 known humidity, using a metliod already described by one of the 

 writers (13), no direct relation was found between the humidity of 

 the air and the amount of rot of the fruit. Berries kept as well in 

 very moist air as in drier air unless they were actually wet. 



NATURAL RIPENING PROCESSES. 



Like other fruits, the cranberry when picked is a living organism, 

 carr3dng on its vital activities, which may be referred to in general 

 as ripening processes. Of these processes one of the most important 

 is respiration. Under normal conditions the respiration of a fruit 

 is marked by taking in oxj'gen and giving off carbon dioxid. In this 

 process the living matter of the fruit is broken down and the berry 

 gradually loses weight. If continued long enough this process would 

 end in the destruction of the berry. It has been demonstrated that 

 respiration goes on more rapidly at high than at low temperatures; 

 consequently, the cooler the berries can be kept without freezing the 

 longer they will live and the better will be their condition. 



SMOTHERING. 



CONDITIONS WmCH CAUSE SMOTHERING. 



In a paper published with the report of the Massachusetts 

 Cranberry Station for 1916 (11) the writers called attention to 

 the spoilage of cranberries caused by insufficient ventilation. As 

 pointed out at that time, cranberries kept in tight cans or in an 

 atmosphere of carbon dioxid lose their crispness and bright color, 

 becoTTje dull red and flaccid, and taste bitter. Since this kind of 

 spoilage is apparently caused by conditions which check normal 

 respiration, the writers designate it as smothering. Experience has 

 shown that whenever cranberries of good keeping quality are cov- 

 ered with some inert gas, such as carbon dioxid, buried for some 

 time in a big pile of berries, shut up in a tight container, kept under 

 water, or subjected to other conditions which prevent normal res- 

 piration, smothering occurs. The exact causes of this spoilage, as 

 well as the nature of the changes brought about in the fruit, are now 

 the subject of investigation by Prof. F. W. Morse, of the Massa- 

 chusetts Agricultural Experiment Station. 



When berries are under water or under carbon dioxid, death due 

 to smothering occurs in a short time, often in one to two weeks, 

 w^hereas in tight containers or in large piles it results so slowly that 

 if the berries are of inferior keeping quality fungous rot may de- 

 stroy them before the effect of smothering appears. In case rot- 

 producing fungi are present, they develop rapidly on the weakened 

 berries, and a mass of rotten fruit results. 



