110 



DISEASES OF ECONOMIC PLANTS 



Texas root rot. See cotton. 



Black mold {Alternaria sp.). — In addition to the ravages 

 of this disease as upon the apple, the leaves and shoots 

 are also attacked and the fruit injury is not limited to 



Fjg. 46. — Young quinces showing mat. After Bailey. 



the blossom end. The disease has been noted chiefly upon 

 the KielTer. 



For treatment, see apple. 



QUINCE 



Rust (Gymnosporangium clavipes C. & P.). — The 

 quince rust, spring stage, agrees with the apple rust in 

 general characters. The causal fungus grows upon the 

 fruit in the summer and produces there myriads of spores 

 which, on the approach of fall, are carried by the winds to 



