MARKET DISEASES OF VEGETABLES. 71 



ally about the stem end. They seldom, if ever, occur in the 

 blossom half of the fruit. 



These cracks are actual wounds. Either before or after 

 the fruit leaves the field, they 'are very likely to become in- 

 fected with rot-producing organisms. From the market 

 point of view, growth cracks assume a very great impor- 

 tance because rots so frequently start in them. 



TOMATO: RING ROT. 



Cause: A fungus (Melanconium). 



A large, circular, flattened lesion, very conspicuous be- 

 cause of its broad, concentric rings, is characteristic of this 

 disease. The background color is brown and the center and 

 the margin may be slightly elevated. Under moist condi- 

 tions acervuli (singular acervulus) , the fruiting bodies of the 

 fungus, appear. The spores which exude from them fre- 

 quently germinate and the resultant white mycelial growth 

 covers the center of the lesions. The rotted tissue is firm, 

 but affected fruits are worthless. Ring rot has been found 

 to a limited extent in Cuban tomatoes. 



Ref. (72a). 



TOMATO: FUSARIUM ROT. 



Cause: A fungus (Fusarium). 



The differentiating symptom of this disease is a heavy, 

 compact, pinkish-white growth of the fungus on the lesions. 

 The advancing edge of the lesions frequently is free from 

 visible fungous growth and is water-soaked and shrunken. 

 The fungus probably attacks the fruit through wounds. 



TOMATO: RHIZOPUS ROT. 



Cause: A fungus (Rhizopus nigricans). 



The general features of this disease have been taken up 

 under the discussion of Rhizopus rot. It is a very soft, leaky 

 rot. Affected fruit has an acid odor and when ripe usually 

 has a bleached appearance. This rot rarely is found on 

 green fruit. 



The fungus attacks the fruit through breaks in the skin. 

 These may be due to careless handling and so minute as to 

 be invisible to the unaided eye, or they may result from skin 

 pricks, nail injury, or mashing in packing or transit. The 

 disease spreads in transit, the fungus growing through the 

 wrapper from diseased to healthy fruit. 



Ref. (56). 



TOMATO: FOUL-SMELLING ROTS. 



Cause: Bacteria and fungi. 



The various tomato rots that are accompanied by foul 

 odors have not been studied sufficiently to be differentiated 

 and named. 



TOMATO: SUN-SCALD. 



(See Sun-scald). 



