FRUIT DISEASES. 297 



Pear-leaf Cluster-Cups (Gymnosporangium sabina?). 

 Not a serious disease. It produces rugged swellings on 

 the leaves. Burn infected leaves. 



Pear Scab (Venturia pirina). A similar disease to the 

 Apple Scab, previously described. Same remedies apply. 



Stone Fruits. 



Apricot Brown Rot. See Apple Rot Disease, in pre- 

 vious section. 



Cherry-leaf Scorch (Gnomonia erythrostoma). A dis- 

 ease which attacks the leaves and eventually the leaf- 

 stalks. The result is, the sap is prevented passing to the 

 leaves, and they consequently wither, and have the appear- 

 ance of having been scorched. The dead leaves hang on 

 to the shoots until the following year. Gathering and 

 burning all withered foliage in winter or earlier is the only 

 remedy. 



Cherry Mildew (Podosphsera oxyacanthae). This forms 

 white powdery patches on both sides of the leaves, and in 

 cases of a bad attack seriously cripples the growth of the 

 tree. Spraying with Bordeaux mixture at half the usual 

 strength when the leaves are young checks the develop- 

 ment of this fungus. 



Peach-leaf Curl (Exoascus deformans). Leaves of the 

 Peach and Nectarine are frequently attacked by this 

 fungus. The leaves have a puckered and swollen appear- 

 ance, and are coated with a whitish mould, similar to 

 mildew. The disease prevents the leaves carrying on 

 their proper functions, and hence they soon become sickly 

 and die. The mycelium of the fungus lives in the young 

 shoots, and then passes on to the leaves. Infected leaves 

 should be removed early and burnt, and it is a good plan 

 to also remove and burn shoots that have borne infected 

 le'aves. Spraying with Bordeaux mixture before the flower- 

 buds expand will do much towards checking the spread 

 of the disease. 



