SUGAR-CANE 81 



usually protected by the leaf-sheaths. In some places 

 the fungus is said to grow on the dead canes only and 

 the disease is not known. 



It is widely distributed throughout the sugar- 

 growing countries of the world, and in fact it is 

 extremely doubtful if there are any sugar - growing 

 districts where it does not exist, although it may be 

 much more destructive in some places than others. It 

 occurs in the West Indies where it is known as " red 

 rot," and in Java where it is known as "red smut," 

 although it is not caused by a smut fungus and must 

 not be confused with Ustilagineae. It is also known 

 in Queensland, Barbadoes, India, Hawaii, Madagascar, 

 and the United States. 



The character of the treatment depends somewhat 

 on the severity of the disease and its behaviour in the 

 locality in which it is destructive. 



First of all, great care should be taken to use none 

 but healthy stock for planting, and if possible nothing 

 but immune varieties should be used. Second, the old 

 fragments of stalks and leaves and other rubbish on 

 which the fungus is known to be growing saprophyti- 

 cally should be destroyed if the conditions of cane 

 culture in that locality make such treatment practical 

 and profitable. 



The "Rind Disease" (Trichosphaeria sacchari, 

 Massee, or Mdanconium sacchari, 1 Massee) (Fig. 38) 

 is a stem disease which first attracts attention by a 

 premature yellowing and drying-up of the leaves. This 

 is followed by the death of the entire plant. Some of 

 the joints of the diseased canes show dark discoloured 

 patches which indicate the presence of the fungus. 

 These areas become sunken and of a dull yellow colour, 

 and finally the entire cane becomes discoloured and 

 brown and light in weight. Eventually small black 

 eruptions come through the surface, and are sometimes 

 prolonged into curved black thread-like structures which 



1 Other synonyms are : Strumella sacchari, Cooke, from Queensland ; 

 Coniothyrium malasporium, Sacc., from Porto Rico ; Trullula sacchari, E. & E. 



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