DISEASES OF PLANTS. 749 



The cause of cotton boll soft rot, it is stated, lias not been determined, but it 

 is suggested that the probable cause is a species of Pythium or Phytophthora. 

 The loss due to this fungus is considerable and is found to be greater when the 

 growth of the plant is crowded. 



[Plant diseases in Jamaica, 1913], R. S. Martinez {Ann. Rpt. Dept. Agr. 

 [Jamaica], 1913, p. 16).- — The study of banana diseases results in the statement 

 that rotation of crops appears to be imperative in all serious cases, replanting 

 with bananas on infected land being out of the question in the case of Panama 

 disease and the application of Bordeaux mixture beiag impracticable to the 

 majority of owners in case of black spot disease. Careful selection of suckers 

 for planting is emphasized. The application of lime to some soils deficient 

 therein has been shown to increase considerably the resistance of banana plants 

 to parasitic diseases. 



Coconuts have suffered a good deal from leaf disease in some localities. 

 Pestalozzia has proved a serious pest, requiring strong measures. Removal and 

 burning of diseased foliage, followed by thorough spraying with Bordeaux 

 mixture, is recommended, with special attention looking to vigorous growth. 

 Further efforts are to be made to secure a systematic survey looking to the 

 eradication of bud rot, the most dreaded disease of coconuts in this region. 



Mycolog-ical work in Southern Nig'eria, C. O. Faequhaeson {Ann. Rpt. 

 Agr. Dcpt. South. Nigeria, 1912, pp. 6-9; abs. in Agr. News [Barbados], 12 

 {1913), No. 296, p. 286). — Brief accounts are given of a number of diseases 

 observed on rubber, cacae, and cotton. 



The most important diseases of rubber trees are said to be those caused by 

 Fomes semifostus and Hymenoclirete noxia. A stem disease of Para rubber 

 known as the pink disease, caused by Corticium salmnnicolor, is also reported 

 upon. 



The principal diseases of cacao are those caused by the 2 species first men- 

 tioned as attacldng rubber trees, and also pod diseases due to Thyridaria tarda 

 and Nectria bainii. 



The report on the diseases of cotton is divided into the diseases of American 

 and native cottons. The diseases of American cottons that are most trouble- 

 some are those due to physiological disturbances, but other diseases, such as 

 mildew and anthracnose, are also present. The chief disease on the native 

 cotton is termed leaf curl. This seems to be an abnormality reducing the size of 

 the leaves and often restricting flowering, for which no cause has been 

 determined. Another disease of native cotton is characterized by the blackening 

 of the midrib and main veins of the leaves. Bacteria and a species of Fusarium 

 have been found in connection with this disease, but the experiments have not 

 yet showm whether or not they are the primary cause of the trouble. 



The unattached aecial forms of plant nists in North America, A. G. John- 

 son {Proc. Ind. Acad. Sd., 1911. pp. 375-413). — "It has been the purpose of 

 this study to make such separation farther than it had already been made, 

 and to determine as far as possible the number of forms still unattached and 

 to work out clues for probable connection wherever possible. The forms of 

 aecia whose telial connections still remain unknown are arranged and follow 

 in the form of an annotated list preceded by a provisional key. . . . Under 

 each species are given as far as possible the citation of the original description 

 and date of publication, the hosts inhabited, the States and provinces in which 

 the species has been found on each host, the type locality, type host, general 

 distribution, and reference by number of specimens published in sets of exsiccati. 

 Notes follow in most cases." 



An index of species of iEcidium is given, also an index of the genera of 

 hosts. 



