

QUINCE DISEASES 



391 



Symptoms. 



Diseased fruits (Fig. 114) are very conspicuous in July and 

 August. The injured portion is covered wholly or in part by 

 masses of orange fringe-like growths, the whole presenting a 

 yellow woolly appearance (Fig. 114). Some fruits are attacked 



FIG. 114. Quince-rust. 



FIG. 115. 

 Rust on quince- 

 twig. 



at the stem end, others at the calyx-end. Again the whole 

 fruit is involved and it may fall. More often, however, it 

 hangs to the tree, dies, and becomes black and hard. There 

 is usually considerable distortion. 



Twig-infections (Fig. 115) are commonly found at the base 

 of new shoots, and knots are produced which resemble black- 

 knot of plums. 



Cause. 



The quince-rust fungus, Gymnosporangium clavipes, has a 

 peculiar life-history. A part of its cycle is spent on the quince 



