WINTER INJURY IN RELATION TO SPECIFIC FRUITS 335 



from autumn rains and both raspberries and blackberries came through 

 in good condition without protection. Growers of raspberries in Wyom- 

 ing are advised to stop irrigation about Aug. 1 but to give a heavy late 

 fall irrigation, besides covering the plants. ^^ There is general agreement 

 that cane fruits suffer more in seasons and in sections with little snow. 



It is possible that much of the benefit attendant upon covering canes 

 comes from the reduced drying out rather than from actual protection 

 from cold. Even a trivial protection seems sufficient, sometimes just 

 enough to hold the canes down. Lying prostrate without covering they 

 escape most of the drying effect of the wind; when covered with earth 

 or snow they will resist extreme cold. Such protection is essential in 

 some sections, in others the profit in the operation depends on the 

 variety grown. Thus, in some experiments at Ottawa it was found that 

 the increased yield resulting from protection of the hardiest varieties 

 did not repay the cost of the operation though other less hardy varieties 

 thus treated gave 16 to 22 per cent, greater yields or enough to leave a 

 profit for the work.*^ Incidentally, it was reported that the plants thus 

 protected ripened their crops 5 to 8 days ahead of those not protected. 

 In Colorado minimum temperatures around zero ordinarily do not neces- 

 sitate covering raspberry canes ;^^ in New York unprotected raspberry 

 plantations stand considerably lower temperatures without material 

 injury. 



Group and Varietal Characteristics. — The small fruits as a class 

 exhibit a rather wide range of hardiness. Currants probably are to be 

 regarded as the hardiest of all cultivated fruits, with gooseberries only 

 slightly less so. Next in order, in the north at least, come the red rasp- 

 berries descended from native species — those of Europe are tender — 

 followed by the blackcap raspberries which in turn are hardier than the 

 blackberries. There is some overlapping; the hardier black raspberries 

 are hardier than the more tender of the red raspberries and some black- 

 berries in turn are hardier than certain of the raspberries. Least hardy 

 of all are the dewberries, which are really tender though their trailing 

 habit makes possible their culture much farther north than their upright 

 hybrids with the blackberry can be grown without protection. The 

 dewberry and the blackberry, like the plum, are derived from several 

 native species and their range in hardiness is correspondingly wide. The 

 loganberry. Phenomenal berry and allied forms are tender to tempera- 

 tures below 15°F. and the Himalaya and Evergreen blackberries are 

 very little, if any, hardier. On the one hand, then, is the currant, hardier 

 without protection than the apple or the plum; on the other is the dew- 

 berry, rather less hardy than the peach though it is sometimes grown 

 where the peach is not grown, because it is more easily protected. 



Among currants the smaller Red Dutch and Raby Castle types are 

 considerably hardier than the large-fruited varieties, the Fay and Cherry 



