10 MASS. EXPERIMENT STATION BULLETIN 433 



of this relationship. It is believed that material like this can be used efleclively to 

 predict the general keeping quality of cranberry crops and as a guide in conducting 

 bog operations for the control of rots and in arranging programs for the sale of the 

 fruit. It will be seen in the table that the keeping quality of the general crop was 

 appraised as poor in all nine of the years in which both the amount of sunshine in 

 the previous year and the mean temperature of May were above normal and the 

 temperature of March was above 34 degrees. On the other hand, the general keeping 

 quality was at least fair in all but one of the sixteen years in which the sunshine of 

 the year before was less than normal and in all but one of the sixteen years in which 

 the temperature of May was below normal, regardless of all other influences. This 

 connection between sunshine and cranberry keeping quality is probably a sugar 

 relation. The effect of high temperature in May on keeping quality seems to 

 call for a corresponding reduction in the size of the crop. The records, however 

 show no such effect but rather, if anything, a slight increase. It appears, there- 

 fore, that high May temperature tends to increase the size of the crop while it 

 impairs its keeping quality and that the two effects nearly balance each other in 

 the amount of fruit produced and finally marketed. 



The following three of the four weather elements i^that seem to influence the 

 size of cranberries in Massachusetts are found to affect keeping quality also: 



1. Amount of sunshine the year before the crop year (Tables 5 and 6)— the more 

 sun, the larger the cranberries and the poorer their keeping quality. 



2. Sunshine and mean te?nperature of March of the crop year (Table 18)— the 

 more sunshine and the lower the mean temperature, the smaller and sounder the 

 cranberries. 



3. Amount of precipitation in July and August of the crop year (Tables 6 and 

 9A)— the more rain, the larger the berries and the poorer their keeping quality. 



^ This clarifies the strong normal relation heretofore foand between the general 

 size of the berries of a cranberry crop and their keeping quality.ie As the amount 

 of sunshine the year before the crop year (Table 4) is also outstandingly related 

 to cranberry production, it is clear that the size of the crop may serve as something 

 of an indication of keeping quality,!^ but it has proved less reliable than berry size 



Temperature in September and October (Table 7 and Figure 5) seems to lead 

 among the minor factors affecting cranberry keeping. The rate of berry respira- 

 tion and the rate of development of putrefactive fungi in their relation to storage 

 losses are concerned here. (U.S. Dept. Agr. Tech. Bui. 258, 1931, pp 25-38- 

 Mass. Agr. Expt. Sta. Buls. 180, 1917, p. 217, and 192, 1919, pp. 114, 115.) 



The considerable relations between spring temperatures and cranberry keep- 

 ing brought out here seem to do much to explain the connection between the 

 late ripening and good keeping of cranberry crops. ^^ 



General Remarks on'Cranberry Production 



In this paper weather elements in Massachusetts are found to affect the size 

 of cranberry crops, the size of the berries, and the keeping quality of the berries. 

 It is believed that the relations of those elements that seem to affect all three are 

 most likel y to be well established, these being the sunshine in the year before the 



^^The fourth is the amount offsunshine in December and January (Bulletin 402 pp 85-88 ) 

 In this relation, the sunshine at Boston alone for the years 1925 to 1942, inclusive, shows a correla 

 tion coefficient of -t- 0.63 + .096. 



^®Mass. Agr. Expt. Sta. Bui. 402. 1943. p. 88. 



l^Ibid. p. 75. 



l^Ibid., p. 91. 



