The Ajp2)le. 65 



4. The apple is mostly propagated by budding or root- 

 grafting on apple seedlings. Root-grafting with long cions 

 is preferred in severe climates (46). 



5. Apple trees are commonly planted in the orchard at 

 three years old from the bud or root graft. If expected to 

 attain full size, they should not be set less tban 30 to 35 feet 

 apart. 



6. The codling moth, canker worms and leaf rollers 

 may be held in check by timely and thorough sprayings 

 with water containing Paris green at the rate of 1 pound 

 to 200 gallons. For the first-named insect, bands of burlap 

 placed about the trees in summer are helpful by enticing 

 the larvas to pupate where they may be easily destroyed; 

 gathering and feeding out the fallen infested fruit is also 

 helpful (49, 54, 55). 



T. The apple-tree borers may be held in check by prob- 

 ing their burrows with a flexible twig, by washing the 

 trunk with the soap-soda solution or by painting the trunk 

 thickly just at the surface of the ground with common 

 paint (57, 58). 



8. The oyster-shell bark-louse inay be controlled by keep- 

 ing the trees in a vigorous condition, or by spraying the 

 infested parts with a kerosene emulsion containing an 

 abundance of soap (59). 



9. The San Jose scale may be removed from nursery 

 trees by fumigating them in a close room with hydrocy- 

 anic gas. Orchard trees may usually be freed from it by 

 spraying them during winter with a solution of whale-oil 

 soap or with crude petroleum (60). 



10. The aerial form of the woolly-louse may be controlled 

 by spraying with a strong kerosene emulsion, and the root 

 form by the free use of tobacco dust about the roots (61). 



5 



