354 



The Spraying of Plants. 



are united, the diseased part assumes an irregular outline. Badly 

 infested leaves turn yellow and fall to the ground during the 

 latter part of summer, or early in the fall. Trees very com- 

 monly lose all their leaves in this manner. Upon the fruit, if 

 the attack takes place after the quince is nearly grown, dark 

 brown or nearly black sunken areas are formed, these being 

 more or less thickly scattered over the surface, as shown in 

 Fig. 83. If the quince is affected while it is small, its shape 



may be much altered, for 

 the flesh becomes cracked 

 and corky in the diseased 

 places. Such fruit is only 

 too familiar to quince 

 growers. The fungus also 

 attacks pears. 



Treatment. The method 

 of treating this disease has 

 already been mentioned 

 under leaf blight of the 

 pear. The two fruits are 

 treated in a similar man- 

 ner, but the applications 

 made upon the quince 

 during the latter part of 

 June and in July are the 

 most important ones. 



Ripe Rot. See under 

 APPLE. 



Rust (Roextelia auranti- 

 aca, Pk.). Description. 

 This disease (Fig. 84) "is 

 very conspicuous upon the fruit, as it covers the injured portion 

 of the quince with an orange, fringe-like growth. The tube-like 

 projections of the fungus contain numerous spores, and when 

 this stage is apparent, the fruit is already irrevocably ruined. 

 Sometimes the entire young fruit is involved, and it may die 

 and fall ; but more often the fruit hangs upon the tree, and 

 the diseased portion becomes dry, hard, black, and sunken. 

 . . . This rust fungus also penetrates the twigs, and often 

 causes knots to appear, resembling the black knot of the 



FIG. 83. Quince attacked during the latter 

 part of the season by fruit spot. 



