WEATHER AND CRANBERRY PRODUCTION U 



The following matters, supplementary to the material in Table 6, may deserve 

 attention: 



1. Springs much colder than normal have never been followed by a large 

 cranberry crop. The springs of 1888, 1907, 1916, 1917, 1920, 1926, and 1940 

 are noteworthy here. 



2. Temperatures of March, July, and September-October and rainfall of 

 March-April show some correlation with size of crop. (Bulletin 433, pages 13, 

 24, and 26.) 



Sunshine and the Size's of Massachusetts Cranberries 



In 1943 Franklin'^ pointed out that sunshine in December and January pre- 

 ceding the crop favors the size of berries. After further studies^^ he also found 

 that the total sunshine of the calendar year preceding the crop is strongly related 

 to the size of berries; and in Table 18 of Bulletin 433 he has related the sunshine 

 and temperature of March to the size of berries in the coming crop. 



Table 7 presents a month-bj'-month analysis of the relation of sunshine to size 

 of berries for each of the twenty-one months directly- preceding the crop. 



Table 7. — Sunshine and the Size of Massachusetts Cranberries. 



(Correlation coefficient and probable error for each month.) 



Year Before Year of Crop Year of Crop 



January _ - .1259 ± .1448 January- .+ .4195 ± .1213 



Februar)- +.1712 +.1428 February +.1408 + .1442 



March +.4280 ± .1202 March.' - .0854 + .1461 



April .,,....... + .3093 + .1330 April - .1401 ± .1442 



May - .0447 ± .1469 May .. - .0594 + .1419 



June - .3973 ± .1239 June + .1652 ± .1432 



July - .0013 ± .1471 July. - .1003 + .1457 



August + .1723 ± .1428 August - .2612 ± .1371 



September + .3069 + .1333 September - .0478 ± .1470 



October + .5976 ± .0946 



November + .0114 ± .1471 



December. . + .1801 + .1424 



It is clear from Table 7 that the sunshine of March, April, June, September, 

 and October of the year before the crop year and of January of the year of the 

 crop is most important in developing the size of berries. Of these six months, 

 only June has a negative coefficient; apparently- the more sunshine, the smaller 

 the berries. 



Table 7 gives + .1801 ± .1424 as the insignificant coefficient derived from the 

 relation of December sunshine and the size of berries of the following crop. In 

 1943 Franklin 1* reported a coefficient of + .442 + .128. The discrepancy is due 

 to the inclusion in this report of data for 1944. This year, which produced the 

 smallest berries on record, was preceded by a December with 24 hours in excess 

 of normal sunlight. 



'° The data on size of berries used in this paper come from C. D. Stevens. See Franklin, Mass. 

 Agr. Expt. Sta. Bui. 433, 1946. 



16 Mass. Agr. Expt. Sta. Bui. 402, 1943. 

 '■^ Mass. Agr. Expt. Sta. Bui. 433, 1946. 

 '^ Mass. Agr. Expt. Sta. Bui. 402, 1943. 



