328 FUNDAMENTALS OF FRUIT PRODUCTION 



growing latest were the least injured. This finding is in agreement with 

 Goff's earlier report of greater tenderness in the winter of 1896-1897 when 

 the trees stood in sod and the weather was dry, both of which conditions 

 favor early formation and rapid development of fruit buds. It appears, 

 then, that cultural practices tending to promote vigorous growth and 

 fairly late maturity would have some effect in reducing injury of this sort, 

 though Roberts states that it could not be eliminated altogether. 



In a general way, it may be said that the cherry is not very liable to 

 injuries associated with immaturity. Some varieties of sweet cherries 

 were shghtly injured in Michigan in October, 1906, when peach trees were 

 killed and pears considerably injured in some places. ^^^ Cherries, how- 

 ever, showed considerable injury in Washington in late November, 

 1896, at a temperature somewhat below 0°F.^2 



Bessarabian, Brusseler Braun, Lutovka, English Morello and Early 

 Richmond appear, from the scant data available, to be the hardiest of 

 the commonly grown varieties. 



The Plum. — Perhaps because of the number of botanical species from 

 which the cultivated varieties have sprung, plums show a wide range in 

 hardiness; though some are more tender than the majority of peaches, 

 others are hardier than the hardiest apples. Hedrick^^ states that the 

 Nigra plums are the hardiest of our tree fruits and are able to resist 

 nearly as much cold as any cultivated plant. Only a little less hardy are 

 the Americanas. The relative hardiness of the other groups is thus 

 summarized by Hedrick: "Insititias as represented by Damsons come 

 next with varieties of Domestica as Arctic, Lombard and Voronesh 

 nearly as hardy. The Domesticas are less hardy than the apple, ranking 

 in this respect with the pear. Of Domesticas the Reine Claude plums 

 are as tender to cold as any though some consider Bradshaw more tender. 

 . . . The Triflora (Japanese) plums vary more in hardiness than any 

 other of the cultivated species. Speaking very generally they are less 

 hardy than Domesticas, the hardiest sorts, Burbank and Abundance, being 

 somewhat hardier than the peach, while the tenderest varieties, of which 

 Kelsey is probably the most tender, are distinctly less hardy than the 

 peach. Of the remaining plums, the Hortulana, Munsoniana and 

 Watsoni groups, there are great diversities in opinion as to hardiness. 

 Probably all the varieties in these last groups are as hardy as the peach 

 with a few sorts in each more hardy than the peach. It is to be expected 

 from the more northern range of the wild prototypes that the Hortulana 

 and Watsoni plums are somewhat hardier than Primus Munsoniana.'' 



Waugh^o-* indicates distinct varietal ranges, within the species: 

 " The tenderness of Bradshaw seems to belong more to the fruit buds than 

 to the wood and correspondents do not seem to agree in their reports; 

 but upon the basis of statistics received, we may trace the northern limit 

 of the Bradshaw . . . which runs from 100 to 300 miles south of the 



