48 MASS. EXPERIMENT STATION BULLETIN 402 



dangerous part of the spring season than in the fall because of the longer days and 

 higher solar elevation/" 



2. High spring temperatures start the new growth early and so lengthen that 

 season of frost danger. This was the main cause of the injury from the Cape Cod 

 frost of April 28, 1910, high temperatures having persisted through most of March 

 and April. Such spring temperatures also sometimes create a special situation, 

 as with the great frost on the Cape on June 20, 1918, when, because of high 

 temperatures through April and May, many bogs were already nearing full bloom 

 and so could not be flooded safely. High temperatures through August delay the 

 ripening of the berries (pp. 89 and 91) and thus make them more liable to frost 

 injury in early September. This was the situation with the destructive frost of 

 September 10, 1917. 



Table 5. — Average Departure of the Mean Daily Temperatures From 



Normal During the Ten-Day Periods Before the More 



Harmful Cranberry Frosts — New Jersey. 



(Degrees Fahrenheit) 



Date of Frost Imlaystown Indian Mills Lakewood .\verage 



Sept. 14, 1895 +4.70 - - +4.70 



Oct. 1, 1899 -2.95 - - -2.95 



May 28, 1902 +6.70 +8.50 +6.85 +7.35 



Sept. 21, 1904 +0.25 +0.25 +2.75 +1.08 



May 20, 1905 +4.65 +5.85 +6.20 +5.57 



Sept. 15, 1913 -2.80 -1.35 - -2.08 



Sept. 10, 1914 +0.15 +0.50 +1.15 +0.60 



Sept. 10, 1917 - -5.1)5 -5.35 -5.65 



Sept. 19, 1920 -0.50 -0.80 +0.80 -0.17 



May 23, 1921 +4.00 +3.60 +4.65 +4.08 



May 25. 1925 +1.50 +3.30 +2.75 +2.52 



May 27, 1927 -1.50 +1.05 -0.30 -0.25 



May 14, 1936 - +9.20 +9.70 +9.45 



May 30, 1938 - +0.95 +1.65 +1.30 



June 20, 1940 - +4.55 +4.90 +4.72 



Table 6. — Average Departure of the Mean Daily Temperatures From 



Normal During the Ten- Day Periods Before the More 



Harmful Cranberry Frosts — Wisconsin. 



(Degrees Fahrenheit) 



Wisconsin 

 Date of Frost Meadow Valley Neillsville Rapids Average 



May 29. 1884 - +0.60 - +0.60 



Aug. 23, 1891 0.00 -3.10 -0.50 -1.20 



Aug. 29, 1893 -0.50 -1.40 - -0.95 



Aug. 20, 1895 -0.85 -2.70 +1.20 -0.78 



June 29, 1900 +4.40 +4.50 - +4.45 



June 10, 1903 +1.10 +1.35 +2.40 +1.62 



Aug. 7, 1904 -3.75 -3.05 -4.35 -3.72 



Sept. 1, 1909* +2.70 +5.20 +3.80 +3.90 



June 8, 1913 +3.65 +5.35 +2.75 +3.92 



July 18, 1929 +0.15 +0.95 +0.35 +0.48 



* This frost came after a long drouth and the cranberry growers lacked water for flooding. The 

 soil must have been dry to an unusual depth. (Cox, op. cit., pp. 10 and 117.) 



3. The freezing point ot plant parts generally varies with the concentration of 

 their cell sap, so this considerably determines the temperature they will endure.^^ 

 If conditions, like high temperatures or the free use of fertilizers, have favored 



^''Cummings.N. W., Natl. Res. Council Bui. 68, 1929, pp. 47-56, (Amer, Geophys. Union Trans.) : 

 Richardson, Burt, Evaporation as a function of insolation. Amer. Soc. Civil Engin. Trans. 95; 

 996-1019, 1931. 



°°Schoonover, Brooks, and Walker, op. cit., p. 14. 



