FUNGOUS AND BACTERIAL DISEASES 



211 



parasites destroy more timber annually than do forest fires. 

 The visible portions, the sporophores, of these tree-destroying 

 fungi are pushed out at certain seasons, or during certain 

 weather conditions, and pour clouds of spores into the air to 

 infect surrounding trees. These disease breeders should be 

 the first to be made into firewood in annual cutting from the 

 wood lot. The sporophores should also be destroyed as soon 

 as they appear. By a little intelligent cooperation a commu- 

 nity could bring these pests under control, and however 

 valuable the trees may 

 be in themselves, the 

 study will be worth 

 while as an example 

 of spread and preven- 

 tion of disease. 



Root rot of fruit trees 

 is a matter that will call 

 for special attention in 

 certain sections. Two con- 

 spicuous mushrooms, Cli- 

 tocybe parasitica and the 

 common honey mush- 



FIG. 100. Apple inoculated, at pin, with 

 spores of .brown rot from mummied plum. 



Control apple 

 As instructive as a case of smallpox 



room (Armillaria mellea), show strong parasitic tendencies when-brought 

 into contact with the roots or crowns of apple, peach, or cherry trees. 

 In clearing land for orchards it is advisable to remove all stumps and 

 roots that are likely to harbor these fungi. 



Invite the local forester or tree surgeon to discuss these problems 

 with the class. Learn from him the best treatment for tree wounds. 

 (Wounds of any size made in pruning should be sealed with paint or 

 gas tar.) As laboratory work let the class, in convenient groups, make 

 some experiments in tree surgery where most needed about homes, 

 school yard, or streets. 



Civic types for study. Duggar describes, or mentions, in 

 his book " Fungous Diseases of Plants," 238 fungi that 

 attack the common plants and trees of forest, orchard, 

 garden, and field. He also gives a most useful Host Index 



