WEATHER IN CRANBERRY CULTURE 37 



Most of the cranberries that freeze in a frost in the picking season often thaw 

 out and show no injury.'^ They may stand repeated freezing and thawing if the 

 temperatures are not too low, but this is not beneficial. 



Frost in cranberries is sensed readily with the teeth, the "bite" being distinc- 

 tive. The frozen berries shaken together rattle like marbles. 



Cranberries frozen on a bog when they are ripe or ripening are fair canning 

 material, so they can be salvaged, but they sell at a lower price than the sound 

 fruit. Berries some of which have been frozen usually become sticky and hard to 

 sort for the fresh fruit market. Such fruit is in better condition and more easily 

 handled when it is not picked for ten days or more after the freezing. 



Harm to the terminal buds of cranberry vines from late-summer or fall frost 

 has hardly ever been observed in Massachusetts^" or New Jersey. Such injury 

 on August 8, 1904, in Wisconsin reduced the 1905 crop about 25 per cent and has 

 been important there in other years.^^ The new growth of vines on New England 

 bogs flooded in the summer for grubs is tender in the early fall and, unless pro- 

 tected from frosts, is likely to lose its buds. 



Cox has shown-- that minimum air temperatures on cranberry bogs on clear, 

 cool nights are lower 5 inches above the ground than at the surface, especially in 

 October, the difference sometimes reaching 6 or 7 degrees. The distance above 

 the ground of the lowest temperatures on such nights must vary with the vine 

 growth, for they must be at the radiating surface made up of the tops of the vines. 



Cranberry Observing Stations and Minimum Temperature Formulas 



With the help of the late John W. Smith, then in charge of the New England 

 Section of the Weather Bureau, and of the late Henry J. Cox, in charge of the 

 of the Bureau's work in Chicago, three special observing stations were established 

 in the cranberry district in April 1912. They were located at Marstons Mills 

 (at the bog of Mr. Chester Crocker) in Barnstable County, and at East Ware- 

 ham( at the Cranberry Experiment Station, elevation 18 feet) and South Carver 

 (at the bog of the Atwood Bog Company) in Plymouth County. Similar stations 

 at Norton in Bristol Count}' (at the bog of the Fuller-Hammond Company) and 

 at Halifax in Plymouth County (at the bog of the United Cape Cod Cranberry 

 Company) were started in April 1913. Stations at South Hanson (at the packing 

 house of the United Cape Cod Cranberry Company) and Pembroke (at the John 

 Hill bog of the United Cape Cod Cranberry Company) in Plymouth County were 

 added in May 1919. 



Weather records of the frost seasons have been made at all these stations yearly 

 since they were started. Study of these records, begun in the winter of 1917-18, 

 was pursued to find formulas for predicting cranberry bog frosts and their degree 

 of cold. Computing of minimum temperatures from relative humidity, then in 

 favor with Prof. J. W'arren Smith,^^ who had charge of the Weather Bureau work 

 in agricultural meteorology, and with students of frost problems in the West, 

 was tried and, with other methods that had been advanced, found unsatisfactory 

 for cranberry frost work. Original formulas were then developed by trial, every 



^^Cox, op. cit., p. 91; Franklin, op. cit., p. 30. 

 Many terminal buds were killed on Early Black vines on a bog in Wilmington by the frost of 

 August 24-25, 1940. 



Cox, op. cit., p. 121; Lewis, C. L., Report of the thirty-seventh annual meeting of the Wisconsin 

 Cranberry Growers' Association, 1924, p. 41; Bain, H. F., Report of the forty-second summer 

 convention of the Wisconsin Cranberry Growers' Association, 1928, p. 11; Weather forecasting 

 in the United States, W. B. 583, 1916, p. 180. 

 22Cox, op. cit., pp. 35, 36, 76, and 89. 



- Smith, J. Warren, and others, Predicting minimum temperatures from hygrometric data, U. S. 

 Monthly Weather Rev., Supplement No. 16, 1920. (Copy in the Middleboro library.) 



