34 



VARIETIES AND NURSERY STOCK 



be corrected, as we are able to learn more concerning the behavior of these 

 varieties under different conditions. 



" In Table II these same varieties are grouped under their optimum 

 temperatures for convenience in reference. 



" In Table I there is also given for some varieties the range of tempera 

 ture which they can stand without serious deterioration. This is, as 

 already stated, closely connected with the season of the variety, being wide 

 with early sorts and relatively narrow with most winter sorts. Just how 

 much difference there is between the ranges of varieties of the same season 

 is difficult to say. It is complicated with a variety of related questions. 



" In the case of a few of the varieties given in Table I an attempt is 

 made to give their hardiness with respect to the winter cold. Inasmuch 

 as the ability of the tree to withstand cold depends on a variety of factors 

 other than the temperature, it is of no use to attempt to state this in degrees. 

 The designation Ex. H. is used for the varieties equal in hardiness to those 

 classified as of the first degree of hardiness (by the Minnesota Horticul- 

 tural Society) ; and the designation H., M. and T. for various degrees of 

 hardiness below these two classes. Many of the more southern sorts are 

 not grown far enough north on account of a lack of summer heat to test 

 their winter hardiness in a satisfactory manner. Therefore it is impossible 

 to make any statements regarding them, nor would there be any practical 

 value in such statements were they possible." 



TABLE I. Mean Summer Temperatures. 



(Dr. J. K. Shaw) 



*The average of the mean monthly temperatures for March to September inclusive. 



