247 



of wood above ground, and an equal amount below. Experience shows 

 that the sum of these will not vary more than from 16 to 24 pounds 

 for the total Aveight of wood added to the entire tree in a year's growth. 

 The trees in question yield on an average 3 bushels of fruit each year, 

 weighing 45 to 50 pounds per bushel. The weight of leaves produced on 

 the same tree is about 20 pounds, and varies in about the same proportion 

 as the wood. The number of dwarf trees (10 by 12 feet apart) on an 

 acre is 363. 



The following tables will show the exhaustion of the mineral constit- 

 uents of the soil by weight in pounds, in the yearly growth of wood above 

 ground on an acre of orchard in which the arrangement of trees is as above 

 indicated : 



The pure ash of the wood of the pear we found to be .27 per cent. 



No. 1- 



Xo. 2- 



No. 3- 



No. 4- 



No. 5- 



No. .5- 



No. 7- 

 No. 8- 

 No. 9- 

 No. 10- 

 No. 11- 



-Pear. Duohess 



-Pear, Barre Adjou . . 

 -Pear, Sickles .... 



■Pear, Bartlett 



Pear. Duchess 



-Pear, Vicar of Wakefield 



Pear, Howell 



Plum, IjOmbard . . . . 

 Plum, Lombard . . . . 

 Plum, Lombar<l Roots 

 Peaeb, Late Crawford . 



.40 



diff! 



.47 

 .15 

 .64 



These tables give quite an accurate idea of the amount of mineral con- 

 stituents a tree takes from the soil and also of the exhaustion of orchards 

 to the land. 



The amount of lime (CaO) taken up by the trees on an acre varies 

 from 3.6 lbs. to 5.3 lbs. The potash (K3O) from 2.5 lbs. to 3.6 lbs. and 

 the variation in the other mineral constituents taken from the soil can be 

 seen in the tables. The Bartlett pear is the least and the Sickles pear the 

 most exhaustive to the land. Plum trees are not one-half so exhaustive 

 as pears while the peach tree is less exhaustive than either. 



The figures regarding the number of trees on an acre, also the yield of 

 fruit per tree and its weght, are taken from Prof. Bailey's Horticulturist's 

 Year Book. The weight of wood added to a standard pear tree is five 

 times that added to a dwarf tree, but the number of trees on an acre is 

 one-fifth as many, therefore the exhaustion to the land would be about 

 the same. It is interesting to compare the amount of mineral constitu- 

 ents required for the yearly growth of trees, with that necessary for some 

 of the more common field crops. 



