622 Agricultural Experiment Station, Ithaca, N. Y. 



chemical laboratory are unnecessary. Suffice it to say, that every 

 precaution was taken to prevent any change from evaporation or otlier 

 causes between the time of picking and the time wlien they were 

 handed over to the chemist,* October 1st, for analysis. 



Table I. 



Leaves from a Wagner apple tree 13 years old, 18 to 20 feet high. 

 Total weight of leaves 33.18 



Composition of Original Substance. 



Ash. Nitrogen. Phos. acid. Potash. 



Water 47.989^ 

 Dry substance" 52.02% P-53% 1-85% .488% 1-76% 



The above table shows from the small per cent, of water, that the 

 leaves had performed their full functions and that no more changes 

 in the ash content were likely to take place. 



The Handbook of Experiment Station work gives the composition 

 of apple leaves collected at various times as follows : 



Table II. 



Water. Ash. Nitrogen. Phos. acid. Potash. 



In May 72.36% 2.33% .74% .2.^% .25% 



In September 60.71 3.46 .89 .19 .39 



If the leaves of the tree experimented with had been collected in 

 May and had contained as much water as is shown in the last table, 

 there would have been 50 pounds instead of 33.18 pounds. It is 

 probable that the first table shows more nearly than the second the 

 percentages of fertilizing constituents taken from the soil by the leaves. 



The following gives the total weight and content of the leaves of 

 the single apple tree and also the amount of plant food contained in 

 an acre of like character, assuming that the trees were set 35 feet 

 apart, which would give 35 trees per acre : 



Table III. 



Single tree. Amt. per acre. 

 lbs. lbs. 



Total weight leaves 33.18 1161.3 



Total weight water 15.92 557.2 



Total weight dry matter 17.26 604.1 



Total weight nitrogen 29 10. 15 



Total weight phosphoric acid 08 2.80 



Total weight potash 28 9.80 



* The analytical work of this Bulletin was performed by Mr. G. W. Cavanaugh 

 under the direction of Professor G. C. Caldwell. 



