142 GRAFTAGE. 



these lands contain little crude clay, and therefore do not 

 suffer quickly from the burning out of the humus. 



Although the chemical analyses of nursery trees show 

 comparatively small amounts of the more important plant 

 foods, it may still often occur that nursery lands need fertil- 

 izing. Nitrogen is needed in comparatively large amounts. 

 This is the element which chiefly conduces to strong growth. 

 It is also the one which is most rapidly augmented by the 

 addition of humus and the improvement of the physical con- 

 dition of the soil, as recommended above. When nursery 

 stock is making a poor growth, the grower should first see 

 that the tillage of the soil is made as thorough and perfect as 

 possible, in order to supply additional plant food and to pre- 

 serve the soil moisture. He may then add nitrogen in the 

 form of nitrate of soda or sulphate of ammonia, sowing 

 them at the rate of ;oo to 400 lbs. to the acre. The appli- 

 cation should be made in spring or early summer. He 

 should then be sure that insect or fungous attacks are 

 averted. If the land was originally in fit condition for trees, 

 and adapted to them, these suggestions should afford relief. 



Grades of Trees. — Common opinion demands that a 

 tree, to be first-class, must be perfectly straight and comely. 

 This arbitrary standard is but the expression of the general 

 demand for large and handsome trees. But there are some 

 varieties of fruit trees which cannot be made to grow in a 

 comely fashion, and hence there is always a tendency to 

 discontinue growing them, notwithstanding the fact that 

 they may possess great intrinsic merit. All this is to be 

 deplored. The requirements of a first-class tree should be 

 that the specimen is vigorous, free from disease or blem- 

 ishes, and that it possess the characteristics of the variety. 

 This allows a crooked tree to be first-class if it is a Green- 

 ing or Red Canada apple, because it is the nature of these 

 varieties to grow crooked. A crooked or wayward grower 

 is not necessarily a weak one. It is advisable to top-work 

 weak-growing varieties upon strong-growing and straight- 

 growing ones (see page 1.34). 



