MANURING AND FERTILIZING 



important than many persons would have us 

 think. It Is a fact that where orchards receive 

 good cultivation and a liberal supply of humus 

 commercial fertilizers give but medium results. 



Elements of Fertility. — Three elements 

 are necessary for the growth of apple trees, 

 nitrogen, phosphoric acid, and potash. To 

 these lime may be added, although Its benefit 

 is Indirect rather than direct as a plant food. 

 How badly any of these elements may be needed 

 depends on the soil, its previous treatment, and 

 on the system of management. By learning 

 what are the effects of these elements on the 

 tree and fruit we may determine under what 

 conditions, if any, their use Is advisable. 



Nitrogen promotes the growth of new wood 

 and leaves, giving the latter a dark green color. 

 In fact the color of the leaves and the amount 

 of the wood growth are usually good indicators 

 of the need of nitrogen. Nitrogen in excess 

 develops over vigorous growth and prevents 

 the maturity of wood and buds. It always has 

 a tendency to delay the maturity of the fruit by 

 keeping it growing late. On many varieties it 

 tends to produce poorly colored fruits. 



When trees are making a normal amount of 

 growth in a year — say a foot to three feet or 



87 



