CANE SUGAR. 



12. The Rind Fungus of the West Indies. By Bind Fungus in the 

 "West Indies is meant the black pustules and hyphae that appear on the rind 

 of dead and damaged cane ; it is thus described in the Kew Bulletin. 50 : 



11 Canes infected with rind fungus are first noticed by dark red or brown 

 patches in one or two joints toward the middle or base of the cane. This 

 red patch having made its appearance rapidly spreads upwards and downwards, 

 the infected area darkens in appearance, and is evidently rotten. Little black 

 specks make their appearance between the joints, breaking from the inside to 

 the surface." 



Specimens of affected canes were examined by Massee, who considered the 

 disease to be due to a sphaeriaceous fungus which he named Trichosphaeria 

 sacchari, and he found macro-conidia in the interior, and micro-conidia on the 

 wounded surface of the cane. Both these forms he obtained in flask cultures 

 inoculated with stylo-spores. 



Went thought that Massee' s macro-and micro-conidia belonged to the 

 fungus T. ethaceticm, and suggests the identity of a saprophyte of cane, 

 known in Java as Melancomum sacchari, with the fungus producing the black 

 pustules and Massee's sphaeriaceous fungus. 



Howard, 5 in Barbados, investigated the connection between the 

 Tricosphaeria, the Melanconium and the red smut (rot). His experiments and 

 results may be briefly summarized : 



1 . On canes attacked by rind fungus two organisms are always found 

 a Melanconium and the Colletotrichum falcatum of Went. 



2. The Melanconium inoculated into living cane does not produce rind 

 fungus, the damage being confined to the dead cells around the wound. 



3. Canes infected with Colletotrichum falcatum reproduce all the 

 features of rind fungus. 



4. When canes are infected with Colletotrichum falcatum and after- 

 wards with Melanconium spores, the latter grow. 



5. The Melanconium always follows attacks of Colletotrichum falcatum, 

 but does not itself attack living cane. 



It is to be noted that Howard treats the popular term ' rind fungus ' as 

 synonymous with the Java * rood snod.' This is unfortunate, as the ' red 

 smut ' is essentially a disease of the interior of the cane. 



The Melanconium fungus is one that has been much studied, and other 

 investigators do not treat it altogether as a harmless species. Cobb 37 describes 

 it as 'cane spume,' identifying it with Strumella sacchari. He says, "I 

 believe it is true that in most cases, if not all, this fungus requires the cane 

 to be first in some way injured. Perhaps the frost so injures the arrow of the 

 cane as to cause it to decay and die ; perhaps a borer makes its way into the 

 cane, and thus breaks the rind ; or, again, perhaps the wind twists the stalk 

 and cracks it, or the cane gets injured in any of the numerous possible ways; 



152 



