REPORT OF THE CRANBERRY SUBSTATION. 



113 



2. The Relation of Air Humidity to Cranberry Keeping. 



Table 5 describes three series of humidity tests with cranberries con- 

 ducted at the station, in Hempel desiccators, in which the air was 

 kept at known humidities by exposure to sulfuric acid of various specific 

 gravities.^ In the first two series ventilation was supplied the berries 

 every other day by removing the covers of the desiccators and pumping 

 fresh air into their chambers with a bellows. No ventilating was done in 

 the last series. The fruit was all from the station bog and was hand 

 sorted. Five ounces of berries were used in each test in the second series, 

 and four in the third series. 



The results of these experiments and of others carried out by Dr. Stevens 

 show no definite relation between the air humidity and the rate of decay 

 among the fruit. Berries kept as well in very moist air as in dryer air, 

 unless they were actually wet. The last column of the table, however, 

 shows that the loss of the berries in weight increased with the decrease in 

 the air humidity. Evidently considerable humidity in the air is needed 

 to prevent drying of the fruit. Under the conditions usually prevailing 

 in Cape screenhouses, however, the humidity is probably sufficient to 

 prevent much loss from drying. 



3. Ventilation and Cranberry Keeping. 

 On September 17 three lots, of two bushels each, of uncleaned, freshly 

 picked cranberries from the same area of the station bog were stored in 



1 The method is fully described by Dr. Stevens in Phytopathology, 

 428-432. 



Vol. 6, No. 6, pp. 



