48 POPULAR FRUIT GROWING. 



The chemical elements composing our fruit and agricultural 



crops are oxygen, hydrogen, nitrogen, phosphorous, sulfur, 

 iron, potassium, sodium, calcium, magnesium, chlorin and silicon. 

 Nitrogen, potassium and phosphorous are the elements commonly 

 lacking in the soil and it is these that we look for in the so- 

 called commercial fertilizers and manures. These elements 

 each act differently in affecting vegetation. To be used by the 

 plants they must be soluble in the soil solutions. Soil that has 

 an excess of soluble nitrogen in it encourages a vigorous, soft 

 growth of wood and a dark gre-en color in the leaves. Often 

 such plants are unproductive, but when they bear fruit it is gen- 

 erally large in size. On such land trees are liable to grow late 

 in autumn and as a cons-equence winter-kill. For peaches, such 

 soil is more injurious than for apples and other hardy crops. 

 Nitrogen encourages a growth of wood rather than fruit. Large 

 amounts of potash and phosphoric acid in the soil cause a firm, 

 solid growth of wood, early maturity of plant, high color and 

 extreme fruitfuln-ess but do not increase the size of the fruit 

 like nitrogen. Potash and phosphoric acid, with the proper pro- 

 portions of nitrogen, give the best results, all of these -elements 

 being necessary for healthy plant growth. 



Amount of plant food in a crop of apples. It is interest- 

 ing to note the amount of nitrogen, potash and- phosphoric 

 acid taken from the land by a crop of seventy-five barrels of 

 apples that number being used as it represents a good aver- 

 age crop of apples per acre. 

 TABLE SHOWING THE CHEMICAL COMPOSITION OF 75 



BARRELS OF APPLES. 



Water Dry Matter Nitrogen Phos. Acid Potash 



9563 Ibs. 1687 Ibs. 4.5 Ibs. 2.25 Ibs. 11.25 Ibs. 



or 85% or 15% or .04 % or .02% or .1% 



To raise this crop of apples there are perhaps 50 trees, 

 each one of which is fifteen years old and in its branches, trunk 

 and roots, Wiere are 400 pounds of wood of which 40% is water. 

 It is probably fair to assume that the weight of the new growth 

 of wood of a thrifty apple tree at fifteen years of age is twenty 

 pounds per year, from which the amount of plant food used for 

 the production of wood each year can be readily computed. It 

 is also safe to assume that the amount of plant food yearly set 



