72 THE PEACHES OF NEW YORK 



ductiveness varies very characteristically in dififerent varieties. Environ- 

 ment and care greatly influence fruitfulness yet, notwithstanding, the 

 quantity of fruit borne is often a means of identifying a variety and, of 

 course, must always be considered by the cialtivator and the breeder. 



Resistance to disease and insects is a taxonomic and an economic 

 character of much importance. Thus there are great variations among 

 varieties in resistance to peach-yellows, brown-rot and leaf-curl, the three 

 commonest diseases of this fruit in New York, as there is also in resistance 

 to San Jose scale, the worst insect-pest of the peach in this region and 

 to the peach-borer, the commonest. These examples are multiplied 

 in the discussions of varieties, pains having been taken in the peach- 

 orchards at this Station to determine the relative resistance of all varieties 

 to the pests of this region. 



But little attention need be paid to the old bark on peach-trees, since 

 in all varieties it is much the same and is unimportant to the ctiltivator. 

 The bark of all varieties varies in color on different soils and is always 

 of a lighter hue in cold than in warm regions, in dry than in wet situations. 



The branches and branchlets of varieties are very characteristic. The 

 length, thickness, direction, rigidity and the branching angle are all stable 

 characters of varieties, changing but little with differences in soil and 

 climate. The length of the internode is important as is also color, smooth- 

 ness, amount of pubescence, size and appearance of the lenticels, and the 

 presence of excrescences, — though all are exceedingly variable. 



Both leaf-buds and fruit-buds are used in separating groups of peaches 

 but are too nearly alike in the several groups to be of aid in distinguishing 

 the varieties of any group. Fruit-buds are borne in pairs on the wood of 

 the previous year with a leaf-bud separating the members of the pair. 

 The only characters of buds worth noting are size, shape, color and the 

 angle at which the buds stand out from the branches. 



After the fruits, the leaves offer the best means of determining groups 

 and varieties of peaches. Leaves are variable, it is true, but usually within 

 limits quite easily set, since the conditions causing the variations are easily 

 discovered. The most usual ones are extremes in soil, moisture, light, 

 heat and the age of the wood upon which the leaves are borne. Much 

 care has been taken to illustrate as accurately as possible the leaves of the 

 varieties given color-plates in this text, size and form being reproduced 

 exactly and color as nearly as color-plate printing permits. 



Leaf-size and leaf-form are the first characters of the foliage to study 



