fields of Porto Rico. The fungus occurs not only at the base on the 

 outside of the leaf -sheath, but occasionally near the joint of the leaf- 

 sheath with the leaf-blade. On the leaf-sheaths, the fungus may 

 hasten the drying of the leaf, but does not necessarily pass from the 

 sheath into the stalk. Numerous canes have been observed up to 

 maturity which liad remained perfectly healthy so far as the stalk 

 was concerned, but which had had the fungus on the leaf-sheaths 

 for some months. 



In contrast with the conditions found in green cane, in mature 

 or almost mature cane considerable damage has been observed which 

 appeared to be attributable to this fungus. 



In Naguabo in 1912 a certain field of D625 presented an excellent 

 growth. The planting was wide, i. e., 1 feet between rows, but the 

 stalks had developed well. Before the cane was considered quite 

 ripe enough for cutting, it began to appear diseased, i. e., black pus- 

 tules appeared on the rind, the canes appeared water-soaked, and 

 the tops died. In some cases moth borers were present, but with 

 this exception there appeared no fimgus in any quantity except the 

 rind fungus Melancomum sacchari. In a few weeks' time this dis- 

 ease had spread over the field, not affecting all stalks, but some 

 stalks in many stools. The loss in weight and sucrose before the 

 cane could be cut was considerable. 



Near Rio Grande in 1912 was a field of a large yellow Demerara 

 cane, probably D623 or D116, supposed by some to be identical canes. 

 The growth of the cane at twelve months was excellent, consisting 

 of an abundance of large stalks. It was generally known that this 

 cane contained a comparatively small amount of sucrose especially 

 on low wet soils such as in this case. It was suggested that possible- 

 leaving the cane over for another season would produce a larger 

 sugar content, therefore the canes were left for a period of twenty 

 months. Long j^efore this time had passed many of the stalks had 

 become infected with the rind disease and become entirely rotted 

 down, so that at the end of the period the field was almost an entire 

 loss. 



In tile same vicinity in 1912 fields of the striped (rayada) and 

 the native white cane (Otaheite) , which were only twelve months old, 

 behaved in the way. 



This latter condition of cane tw^elve to fourteen months old rotting 

 back with the rind fungus is not uncommon in Porto Rico. The 

 moth stalk-borer is often associated with the fungus, but is no more 

 common in diseased fields than in those not diseased. The conditions 

 under which this disease occurs are not clear, but everything points 



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