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



ditions and consequent malnutrition of the tree. Such dead growth 

 furnishes a place where the fungus can live and grow, carries it over 

 from one year to the next, and thus becomes a source from which the 

 spores are spread to the fruit by wind, rain, or insects. As already 

 noted, there is evidence that the fungus is often a secondary invader 

 on the fruit, gaining entrance at pits or at other places weakened by 

 other causes. The disease rarely develops until the fruit is quite ripe. 



CONTROL MEASURES 



Control of anthracnose depends on careful handling, the shipping of 

 strong, first-quality fruit, and the avoidance of unduly long storage 

 (longer than about 6 weeks). Temperatures in transit below 50° F. 

 should prevent development of the rot during the usual transit period. 

 It is important to keep the trees well pruned and to use cultural prac- 

 tices that will maintain the trees in good healthy condition, thereby 

 reducing excessive accumulation of dead twigs that may harbor the 

 fungus. 



(See 32, 43, 96, 11 2. ) 3 



BLACK ROT (ALTERNARIA ROT) 



(See Oranges, Black Rot (Alternaria Rot), p. 19, and pi. 13, C.) 



BLUE MOLD AND GREEN MOLD ROTS 



(See Oranges, Blue Mold and Green Mold Rots, p. 19, and pi. 6, 

 B and C.) 



BROWN STAIN (SCALD) 



(See Oranges, Brown Stain (Scald), p. 21, and pi. 12, E.) 



CITRUS RUST MITE RUSSETING 



(See Oranges, Citrus Rust Mite Russeting, p. 22, and pi. 5, B.) 



COLORING-ROOM INJURY 



(See Oranges, Coloring-room Injury, p. 23, and pi. 12, D.) 



EXANTHEMA ( AMMONIATION ) 



(See Oranges, Exanthema (Ammoniation). p. 24, and pi. 15, A.) 



FREEZING INJURY 



(See Oranges, Freezing Injury, p. 27, and pi. 16, A-C.) 



GUMMING 



Among citrus fruits, gumming, not connected with exanthema, has 

 been observed in grapefruit and oranges at injuries, such as thorn 

 punctures, that apparently had occurred several weeks before the fruit 

 was picked. The masses of gum are of an amber color and are always 



3 Italic numbers in parentheses refer to Literature Cited, p. 51. 



