246 Grlomerella cingulata and its Conidial Forms 



anthracnose fungi and they produce similar discolorations. The disease 

 is first visible as a small circular black or greenish black spot, which is 

 generally, but not always, slightly depressed. As the infection spreads the 

 fruit loses its normal red colour and turns whitish yellow or greenish 

 yellow, reddish yellow or straw coloured. It also becomes prematurely 

 dry and very brittle. However, the acervuli of G. piperatum can be 

 readily distinguished from those of the other two fungi by their pink 

 colour, especially when fresh. Colletotrichum and Vermicularia acervuli 

 are not easily distinguishable because of the black colour due to the 

 presence of setae; but the Vermicularia acervuli generally look more 

 bristly and more erumpent as a part of the stroma is above the epidermis. 

 Old Glceosporium acervuli, which have turned black, may be mistaken 

 for Colletotrichum acervuli on superficial examination. 



The disease due to F. Capsici will be treated in a separate paper, so 

 a further account of it is unnecessary. 



G. piperatum E. and E. 



The diseased part of the fruit shows slightly raised points. This is 

 due to the development of acervuli underneath them. With the growth 

 of the acervuli the skin is ruptured by elliptical, triangular or irregular 

 rifts. If the diseased spot be examined with a hand-lens, crater-like 

 structures filled with beaded or cauliflower-like pink growths are visible 

 due to the development of spore masses. The acervuli start from the 

 centre of the diseased spot and are generally concentrically arranged 

 but they may also be scattered. They are, when fresh, oily and flesh 

 pink in colour which may either change to dull light pink w^hen they 

 become old or to black, from margin inwards. 



In the epidermal and sub-epidermal cells hypljae collect together 

 and eventually develop into a pseudo-parenchyraatous stroma; from 

 the top of which conidiophores arise. As a rule the latter are short and 

 conical with a tapering apex but they become much elongated and narrow 

 under extremely moist conditions. They measure 11 -0-18-7 x 2-7-4-9/Lt. 

 From tips of the conidiophores spores are cut off. Under the pressure 

 of the growth of conidiophores and development of spores the cuticle 

 is pushed up and eventually ruptured. At first the raised cuticle keeps 

 the conidia more or less confined underneath it and allows their escape 

 only through a small opening but later the cuticle is completely thrown 

 aside (Plate X, Fig. 2). It is the frayed edges of this ruptured cuticle that 

 give the diseased part of the fruit, at times, a scaly appearance. The spores 

 are held together in a gelatinous mass at the opening of the acervulus 



J 



