MANURING ORCHARDS. 151 



economical and systematic. AVe have suggestions from numer- 

 ous sources in regard to the particuhir needs of particular 

 kinds of fruit for plant food, but we have in the reports of 

 our experiment stations and agricultural societies very few 

 results bearing upon this subject which have been derived 

 from actual experiment. It is quite natural, perhaps, that 

 this should be the case, because fruit growing as a business, 

 or on a commercial scale, is comparatively new, and because the 

 character of the investigations necessary to be carried out in 

 order to obtain reliable data must be continued. The develop- 

 ment of fruit growing as a specific crop has, too, been gradual, 

 and has found its first considerable increase in sections of the 

 country within easy reach of good markets, and upon soils par- 

 ticularly adapted for the purpose, which, perhaps, furnishes an- 

 other reason for a lack of scientific investigation along this line. 



Fruit Crops and Grain Crops differ in Respect to 

 THEIR Needs for Plant Food. — It is obvious, too, that such 

 specific results as have been obtained concerning the needs of 

 general farm crops, as grain and grass, for specific plant food 

 elements cannot be applied Avith any degree of accuracy to fruit 

 crops, particularly the larger fruits, as pears, apples, peaches, 

 grapes, and plums, because these differ from the cereals, grasses, 

 and vegetables, first, in their habits of growth, second, in the 

 character of the produce, and third, in their relation to soil 

 exhaustion. 



In the first place, farm crops, as a rule, require but one year 

 for the entire processes of vegetation and maturation. For fruit 

 crops, with Init few exceptions, the purely vegetative processes 

 continue for at least three years, and with many kinds much 

 longer, while after the fruit-bearing period begins the vegetative 

 processes do not cease, Imt are coincident with the growth and 

 ripening of the fruit. In the second place, the product of the 

 harvest, namely, the fruit, differs very materially in its character 

 from that of ordinary farm crops which mature their fruit and 

 die in one season, because a whole season is required for its 

 growth and development ; that is, it is necessary- that there shall 

 be a constant transfer of the nutritive juices from the tree to the 

 fruit tliroughout the entire growing season, while the growth for 

 each succeeding year of both tree and fruit is dependent upon 

 the nutrition acquired and stored up in buds and branches, as 



