70 



Diseases of Economic Plants 



The remedy, therefore, if practicable, is to remove the 

 cedar trees from the neighborhood of quince trees. This will 

 almost entirely pi-event the rust, although in rare instances 

 a few spores may l)e carried a considerable distance. In 

 case the cedar is too abundant to permit of its complete 

 removal, resort must be had to spraying the leaves and 

 fruit of the quince trees with Bordeaux mixture at the 



Fig. 34. — Young quinces showing rust. After Bailey. 



time when the rust spores are expected to arrive; that is, 

 at the time when the gelatinous spore masses are present on 

 the cedar-apple. 



Blight (Bacillus amylovorus) . — This disease has been 

 sufficiently discussed in connection with the pear and apple. 

 It is only necessary here to indicate that it is the most serious 

 known disease of the quince. The treatment is the same 

 as that recommended for this disease on other pomaceous 

 trees. 



Leaf -blight, black-spot ^"^ (Fabroea maculata (Lev.) Atk., 

 Entoinosporiuni). — Both the fruit and foliage are affected 



