GRAFTING AND NURSERIES. 



255 



The earthing up in compact and clayey soils is not always 

 easy ; the soil wetted by rain hardens and forms a crust, 

 preventing the shooting of the bud. This can be remedied 

 by placing sand round the top eye as shown 

 in Fig. 139, covering it entirely. Covered 

 in this way, the eyes develop normally, and 

 success is assured. 



The earthing - up does not retard the 

 development of the buds; it hastens it, 

 on the contrary, and does not impoverish 

 the scion in reserve matters. It only pre- 

 vents and this is its only use evapora- 

 tion from the scion by sheltering it from 

 wind and sun. The water it contains is 

 necessary to the production of callus and 

 the development of all the tissues. 



(c) Cultural care. The only cultural 

 care required is hoeing and scarifying 

 when necessary. Above all, we must pre- 

 vent weeds from growing, as they injure 

 the grafts, not only with their roots, but 

 also by choking the buds when they come 

 out. 



Watering may be performed when re- 

 quired. But care should be taken not to 

 allow the water to reach above the joint, 

 so as not to favour the liberation of the 

 scion, or to hinder the formation of callus. 



When watering, we may spread over 

 the soil chemical manures (nitrates, super- 

 phosphates, etc.), or any other manure 

 acting rapidly; this will improve the 

 growth of the grafts. For knitting to be 

 perfect, it is indispensable that the in- 

 crease in diameter of both stock and scion 

 be as rapid as possible; a joint constituted 

 by only five or six layers of cells will Drafted Cutting 

 evidently be weaker than one constituted 

 by fifteen or twenty layers. We should, 

 therefore, use every means of increasing the growth of 

 the grafted cuttings. This result is attained by watering 

 in dry weather, and by abundant manuring with very active 

 fertilizers. 



Slender roots of the 

 stock. (b) . Strong 

 roots of the scion. 



