KiS 



Principles of Plant Culture. 



or pine tar, is said to prevent the entrance of the round- 

 headed borer (306). Protecting the trunk with straw or 

 hith, as recommended to prevent sun-scald (ISO), may 

 tend to kee}) out these insects. Borers in the trunk can 

 often be destroyed by probing their holes with a flexible 

 twig. 



312. Leaf-Miners often infest spinach and beets grown 

 f( II- greens, rendering the leaves unfit for use. For these 

 insects ^e can offer no preventive measures of 

 established value. The application to the 

 young foliage of powerful odorants, as coal-tar 

 water or a solution of carbolic acid, may i^rove 

 beneficial. 



313. The Codling-Moth,* which causes so- 

 called "wormy" apples and pears, is controlled | 

 by spraying the trees at the time of egg de- 

 posit, with water containing Paris green (285). 

 The first spraying should be 

 given as soon as the petals 

 (143) fall, to be followed by a 

 second six to 

 ten days later. 

 If much rain 

 falls at this 

 season, the 

 sprayings may 

 need frequent 

 repetition. A 

 drop of poison- 

 ed water should be lodged in the calyx (142) of every 

 fruit, and as this evaporates, the poison deposited on the 



Fig. 7.3. FiG. 73. Fig. 74. 



Fig. 7o. Card of tarred paper, for placing about the 

 stenLs of young cabbage and cauliflower plants. Re- 

 duced one-half. 



Fig. 7i. Tool for cutting the cards. 



Fig. 7.5. Manner of using the tool. The dotted lines 

 show the position of the edge of the tool on the paper. 



■ QarpticapHa pomoneUa. 



