442 



DISEASES OF CULTIVATED PLANTS 



Pods that are severely attacked are often contorted or 

 twisted, and in such instances the mycelium frequently 

 passes quite through the pod and infects the beans. 



The conidiophores burst through 

 the epidermis in tufts on the diseased 

 spots, cylindrical, simple, 45-55 p 

 long; conidia apical, oblong, ends 

 rounded, straight or curved, hyaline, 

 I 5~ I 9 X 3 '5-5 '5 /*. Spines few in 

 number, or sometimes absent, dark 

 coloured. 



Professor Halsted says this fungus 

 is also parasitic on cucumbers, 

 pumpkins, water-melons and musk- 

 melons. If this is correct it may 

 also endanger cucumbers, vegetable 

 marrows, and melons, in this country. 

 Spraying with Bordeaux mixture 

 early in the season will either check 

 or prevent the appearance of the 

 disease. This cannot be continued 

 after the plants commence to bloom. 

 Diseased pods and leaves should be 

 removed. Seed showing traces of 

 infection should not be sown. A 

 damp situation favours the spread 

 of the fungus. 



Halsted, Bull Torrey Bot., 20, 

 p. 246. 



Massee, Card. Chron., May 7, 

 1898. 



Voglino, Fungi dannosi alle Piante 

 Coltivate, pi. 8. 



FIG. \-^o.Colletotrichuin linde- 

 muthianum. i, diseased pod of 

 scarlet-runner ; 2, section through 

 a pustule of the fungus showing 



conidiophores bearing conidia at j r u 



their tips, also two long, sterile presence of a SCHOUS QlSeaSC OI the 



cacao-tree, which appeared under 

 the guise of witches' brooms, which 

 he attributed to a fungus he named Exoascus theobromae. I 

 soon afterwards examined specimens of the same disease from 

 Surinam, forwarded by Mr. Hart of Trinidad to Kew, for 



Witches' brooms of cacao. In 



1900 Ritzema Bos announced the 



