154 Peach-Grcymng 



factor, while in the complete fertilizer all three of the ele- 

 ments are applied. If only one or perhaps two of them are 

 lacking, to apply the one or ones already in the soil in abun- 

 dance is without avail, and the pleasing results that may be 

 observed came from the one element in the complete fer- 

 tilizer that was lacking in the soil. 



Thus, until a peach-grower has demonstrated by experi- 

 ment that his orchard needs a complete fertilizer, it is de- 

 cidedly unbusinesslike for him to apply it. It is likely to 

 be wasteful and uneconomical. To apply in a fertilizer 

 an element of plant-food which is already supplied abun- 

 dantly in available form by the soil itself adds to the cost 

 of production without any compensating returns. 



Several experiment stations have conducted well-planned, 

 comprehensive investigations with a view to throwing light 

 on the plant-food requirements of peach trees. It is both 

 impracticable and unnecessary to discuss here in any con- 

 siderable detail the work done by the experiment stations 

 along this line, but some of the results are especially illu- 

 minating and instructive. The more significant features, 

 therefore, are briefly recounted. 



Van Slyke ^ and his associates endeavored to determine 

 as accurately as possible the amount of plant-food taken 

 by peach and other fruit-trees of mature age in bearing during 

 one growing season. The method of procedure was to col- 

 lect separately all the leaves, fruit, and current season's 

 growth made at the ends of the branches and make chemical 

 analyses of them. One tree each of three varieties of peaches 

 was used, an Elberta nine years old, a Champion, and a 

 Chili (Hills' Chili) seven years old. The results of the analy- 

 ses were presented separately for each variety and show con- 

 1 N. Y. Agr. Expt. Sta. BuU. 265. 



