Fertilizers for Peach Orchards 161 



elements than is the older wood. It was ascertained also 

 that the amount of twig growth in any season was a fairly 

 good index of the rate of growth of trunk and older limbs. 

 The years in which the greatest twig growth occurred were 

 also the years in which the annular rings in the trunk and 

 limbs were the largest. 



The results of these two investigations, one by the New 

 York Experiment Station and the other by the New Jersey 

 Station, tend to confirm each other in the main essentials. 

 The New York analyses show a considerably larger relative 

 use by the tree of potash, though both investigations em- 

 phasize the importance of that element, especially in the 

 fruit, and they call particular attention to a surprisingly 

 large requirement of nitrogen. The New Jersey results 

 also bring to light the fact that in seasons when a crop of 

 fruit was borne, the chemical composition of the ash of the 

 leaves was much lower in phosphoric acid and potash than 

 in years when there was no fruit, thus suggesting the trans- 

 fer of these mineral plant-foods from the leaves to the fruit, 

 a phenomenon more or less well recognized in other connec- 

 tions. 



The results of an investigation carried on by the Arkansas 

 Experiment Station and reported by Thompson ^ and which 

 was prosecuted along lines similar to those followed in New 

 Jersey corroborate in essential particulars the findings in 

 that work. 



It is well to point out here that, though these investiga- 

 tions and analyses show in some measure the plant-food 

 requirements of peach trees and their products, they leave 

 entirely unsolved the problem of how to meet those 

 requirements. 



1 Ark. Expt. Sta. Bull. 123. 



M 



