42 MISC. PUBLICATION 4 9 8, U. S. DEPT. OF AGRICULTURE 



when shipments are being made up for transportation to interior 

 points. 



(See 72, 73.) 



Figs 



alternaria spot 



(Alternaria tenuis Nees) 



Alternaria tenuis is the cause of a spotting of figs that often detracts 

 greatly from their market appearance and value. It is found on all 

 the important varieties and on fruit from both the Atlantic and the 

 Pacific coasts of the United States. 



The disease is first evident as a surface growth of small, grayish- 

 white tufts of mycelium. The mycelium soon darkens to an olivaceous 

 color or even darker, and the spots may enlarge to a diameter of one- 

 quarter or one-half inch. At first the fungus appears to have but a 

 slight attachment to the skin and sometimes can be rubbed off with 

 little evidence of injury, but as the spots enlarge and the tissue beneath 

 becomes slightly sunken, any attempt to remove the fungus also re- 

 moves the skin. 



Alternaria spotting may occur on fruit that is still on the tree but is 

 more common on that which is in transit or held at the cannery or on 

 the market. The disease is confined largely to fully ripe fruit, and the 

 fungus is favored by cracks in the skin and by the sugary solution 

 often found on the surface of figs. 



High humidity tends to increase spotting, but storage at low humid- 

 ity may cause an undesirable shriveling of the fruit. Low temperature 

 offers the best means of controlling alternaria spotting. Figs that are 

 promptly precooled after harvest and kept at a temperature of 45° 

 to 50° F. in transit are not likely to become seriously affected during 

 the usual marketing period. In the absence of precooling facilities 

 initial carbon dioxide treatments reduce the activity of the fungus to 

 about one-third of normal. 

 (See 25.) 



BLACK MOLD ROT 



(Aspergillus niger Van Tiegh.) 



OCCURRENCE. SYMPTOMS, AND EFFECTS 



Black mold rot of figs, often erroneously called "smut," is found 

 on figs on the tree and in the drying yard and also occurs in the packed 

 product. It has been reported only from Georgia and California and 

 so far as known affects chiefly the white varieties, such as Calimyrna 

 and Adriatic. The black Mission and Kadota (a white variety) are 

 much less commonly affected. 



The disease on fresh figs is characterized by a dirty white to slightly 

 pink color of the skin and pulp of affected fruits and a firm to finally a 

 cheesy consistency of the pulp. A mass of white mycelium develops 

 within the fig and eventually cavities are formed that become lined 

 with the black spore masses of the fungus. Infection varies greatly 

 in severity. If severe it gives the fruits a dark translucent appearance 

 by which they are easily identified ; if infection is light, it may produce 

 merely dark or yellowish spots in the pulp, with no spores. "Fruits in 



