INSECTS, FUNGI, PLANT DISEASES, ETC. 



Ill 



portions of many of our cultivated and wild plants. After 

 they penetrate the tissues it is next to impossible to de- 

 stroy them without also killing the plant. The treatment 

 must be applied when the fungus is young, and the 

 parts of the plant susceptible to the attack must be 

 covered with the chemical which will prevent the growth 

 of the fungus. When plants become thoroughly infested 

 with this disease the best thing to do is to remove them 

 and burn them. In the case of trees vigorous pruning 

 sometimes prevents the spread of the trouble, and may 

 eventually eliminate the disease entirely. The reader is 

 referred to table opposite page 181 for the methods 

 recommended for the treatment of fungous diseases. 



Preventive measures are of more value than remedial, 

 in protecting plants from insects. Among those most 

 likely to be of value, are the following: 



Rotation of Crops. — Each species of insect generally 

 feeds on the same species of plant, or at least on plants of 

 the same natural family; hence a constant change of crop 

 prevents the forthcoming brood from finding their proper 

 food, and many of them perish. This is, however, more 

 applicable in the case of field crops than in orchards and 

 gardens. 



Decaying Trees. — Destroy all decaying trees in the 

 neighborhood of orchards and gardens, as they are often 

 a refuge, and tend to propagate insects destructive to the 

 neighboring crops. 



Scraping of the rough bark of trees and washing them 

 with tobacco water, lime water, or a wash of lime, sulphur 

 and clay, or a solution of potash, destroys the hiding 

 places of insects, and manj* of the insects themselves 

 which infest trees. 



Birds and Other Animals. — The encouragement of 

 insectivorous birds and other animals, instead of their 

 thoughtless and injurious destruction, is one of the most 



