PHYSIOLOGICAL CHARACTERS 83 



statement that a new fruit does or does not equal an old and 

 standard sort in this respect puts the matter in the clearest 

 possible way before fruit-growers. In nearly every part of 

 the country, lists showing the relative hardiness of common 

 varieties of the several fruits may be obtained from one source 

 or another, and from these fairly accurate comparisons can 

 be made. 



121. Fruit-bearing habits. — The fruit-bearing habits of the 

 several cultivated fruits seem to be fixed, subject to some modi- 

 fication by pruning and other cultural treatment. Some varie- 

 ties are productive, others less so, and some are unproductive. 

 The age at which plants come in bearing is a marked character- 

 istic of species and varieties, especially in pome-fruits. Wag- 

 ener, Bismark, and Oldenburg, among apples, are examples of 

 varieties that come in bearing in two or three years from setting 

 or may even bear in the nurser^^ row ; Northern Spy and Sutton, 

 on the other hand, often do not bear until set eight, ten or 

 twelve years. These characters are of little worth in classifying 

 but are of prime importance in gauging the value of a variety. 



The biennial bearing habit in pomes has long been considered 

 a varietal characteristic, but several reliable experimenters now 

 seem to have proved that it is due to faulty nutrition whereby 

 trees make too great vegetative growth. There can be no doubt, 

 however, that some varieties have a hereditary habit of bearing 

 biennially, others annually, and that there are other character- 

 istic habits in bearing. Such habits are always noteworthy in 

 descriptions. 



122. Longevity. — Length of life is another constitutional char- 

 acter that must be noted. Species and varieties have different 

 degrees of longevity. Baldwin, Northern Spy, and Winesap are 

 long-lived apples; Rome Beauty, Wealthy, and Wagener are 

 short-lived. These are true varietal differences due to nature 

 and not to nurture and cannot be greatly changed by culture. 



123. Natural resistance to disease and insect pests. — The 

 degree of susceptibility to fungous diseases and insect pests is, 

 in many fruits, a varietal difference which may be used in 

 classifying, especially in grouping varieties. It is to the cul- 

 tivator and plant-breeder, however, that knowledge of the be- 

 havior of varieties to pests is most valuable. 



