200 MANUAL OF FRUIT DISEASES 



FROST-INJURY 

 Caused by the action of low temperatures 



Frost is one of the greatest enemies of the cranberry-grower. 

 It is rather erratic in its occurrence, and very difficult for the 

 average grower to predict; hence the damage is done before 

 any precautions are taken. 



Danger from frost comes throughout the growing-season. 

 In June, 1903, the yield in Wisconsin was reduced twenty-five 

 per cent, and in early August, sixty per cent. 



It is ordinarily supposed that frost-injury comes about by 

 a settling of cold air from the surrounding higher land on the 

 bogs. This, however, is regarded as of little importance. 

 Frost formation is largely dependent on the temperature of 

 the soil, and on heat-radiation from it as influenced by the 

 conditions of the atmosphere. The influence of drainage, 

 sand, the depth and thickness of the vegetation, especially of 

 moss, seem to be controlling factors in the formation of frost, 

 and its effect on cranberries. It has been noticed that even 

 where the general minimum over a bog was 25 Fahr., if the 

 same were well-drained and sanded, it remained unaffected by 

 frost ; while in adjacent plots which were in a moist condition 

 and not sanded, frost destroyed every plant. 



It is advised that plants be sprayed with water every two 

 minutes during a frosty night. Or possibly the spraying 

 may be done just about sunrise, thus drawing the frost out of 

 them gradually before the heat of the sun strikes them. 



REFERENCES 



Whitson, A. R., et al. Preliminary report on cranberry investigations. 



Formation of frost and protection therefrom. Wisconsin Agr. 



Exp. Sta. Rept. 21 : 232-233. 1904. 

 Franklin, H. J. Report of cranberry substation for 1912. Frost 



protection. Massachusetts Agr. Exp. Sta. Rept. 25:210-211. 



1913, 



