44 



Mycologia 



state authorities, with the federal department assisting, is being- 

 directed to prevent the further spread of this insidious and most 

 dangerous disease known to affect the potato. It appears that 

 the disease has been established in some of these villages for at 

 least seven or eight years, where it has been impossible at times 

 to secure even the amount of seed planted. It is deemed advisa- 

 ble that all state authorities should inspect large centers of con- 

 sumption where imported potatoes may have been purchased 

 during the past eight or ten years. 



A comprehensive report on the sugarcane diseases of Porto 

 Rico, by J. R. Johnston and J. A. Stevenson, containing 88 pages 

 of text and 13 plates, recently appeared in the Journal of the 

 Agricultural Department of Porto Rico. It is stated that sugar- 

 cane diseases have been present and serious since 1870, and that 

 some now present several difficult problems. Fungi found chiefly 

 on the roots and lower stalk include Marasmius Sacchari, Hi- 

 mantia stellifera, and Odontia saccharicola, all of which are more 

 or less concerned in the so-called root disease. The principal 

 stalk diseases include red rot, Colletotrichnm falcatum; rind dis- 

 ease, Melanconiiim Sacchari; and a new disease, Cytospora Sac- 

 chari, which seriously threatens certain varieties. 



A number of leaf diseases are of universal occurrence, though 

 none appear to be seriously injurious. Descriptions are given of 

 red spot of the leaf sheath, Cercospora vaginae; red rot of the 

 leaf sheath, Sclcrotium Rolfsii; eye spot, Helminthosporium Sac- 

 chari; ring spot, Leptosphaeria Sacchari; brown leaf spot, Cer- 

 cospora longipes; red stripe ; and wither tip. The only important 

 disease of cane cuttings, which is that due to Thielaviopsis para- 

 doxa, is readily prevented by dipping them in Bordeaux mixture. 



A chlorotic disease occurring on the south coast is described in 

 connection with control measures. Yellow stripe occurs in very 

 limited areas. The new disease (as yet uncontrolled), which is 

 characterized by a mottling of the leaves followed by a stalk 

 canker, occurs in the western portion of the island, occasioning 

 heavy losses. 



