32 MASS. EXPERIMENT STATION BULLETIN 402 



of leveU The vines are as well protected frozen into the ice as any way. A good 

 snow cover Is effective protection, and flooding may be delayed if there is one. 



The winter water should usually be held till about April 1 on Cape Cod and 

 April 8 in Middlesex County. It probably should be let off late in March in 

 New Jersey but be held till mid-April in Wisconsin. 



There is a considerable acreage of bogs on Cape Cod that cannot be flooded 

 at all. 12 These are the bogs which have generally been most affected by the 

 cranberry fruit worm, frost, and drouth. The recent success of sprinklmg systems 

 as protection from frost and drouth on some of these areas and the discovery of 

 effective insecticidal controls for the fruit worm have greatly increased the need 

 for some means of protecting such bogs from the winter. The following are 

 possibilities: 



1. Covering the vines with straw, cranberry rakings, shade cloth, or other 

 like material. This is effective but probably too expensive. 



2. Building up a covering of ice with a sprinkling system in freezing weather. 

 This has not been tried but seems rather promising. 



3. Spraying the vines with a special wax preparation. This may be effective, 

 but the only material so far certainly available seems too expensive. 



4. Use of wind breaks, such as snow fences. 



5. Chemical applications. Here is an unexplored field. 



A list of the more important cases of winterkilling on record as occurring in the 

 three main cranberry states follows: 



Massachusetts 



1. Winterkilling was very severe on Barnstable County bogs in the winter 

 of 1871-72, the vines being killed down to the roots in some localities. Nearly 

 half of the strawberry plants in all New England were killed. Evergreens and 

 Rhododendrons were killed very extensively in nurseries throughout New Eng- 

 land. Great numbers of evergreens died everywhere over the country. Apparently 

 the damage was done by very strong cold winds early in March. 



2. There was considerable winterkilling of cranberries in the winter of 1880-81. 

 Water supplies were low in the fall and early winter. 



3. Severe winterkilling in the winter of 1894-95 reduced the 1895 cranberry 

 crop very materially. 



4. Severe winterkilling was extensive on Cape Cod bogs in the winter of 

 1900-1901. Water supplies were low and many growers were unable to flood 

 their bogs. There was little snow. 



5. There was considerable winterkilling on the bogs in the winter of 1903-4 . 



6. Very severe and widespread winterkilling occurred in the winter of 1904-5 , 

 which reduced the 1905 cranberry crop probably a third. The fact that this was 

 also a year of maximum fruit worm injury suggests that the bogs rather generally 

 had meager water protection, and it is recorded that such was the case. 



7. Considerable winterkilling occurred on the bogs in the winter of 1910-11. 



8. Winterkilling was severe and extensive in the winter of 1916-17. Many 

 bogs winter-flowed the first days in February and some flooded late in January 

 were badly hurt. Unprotected bogs were frozen deeper than the cranberry roots 

 extended for some time before the killing took place, and the vines were exposed 

 to strong, dry, northerly winds most of the three weeks ending February 5. Water 

 supplies were low during the fall and winter. 



9. Winterkilling was severe and extensive on cranberry bogs in the winter of 

 1917-18, one of the most severe in the history of New England. Weather con- 

 ditions attending the winterkilling were much the same as in the previous winter. 

 Ponds and streams were low during the fall and winter. 



l^Mass. Agr. Expt. Sta. Bui. 332, 1936, p. 9. (Copies in the Middleboro library.) 



