DISEASES OF PLANTS. 741 



It is believed tliat in working along this line the breeding of disease-resistant 

 varieties can be best accomplished. 



Some problems of plant pathology in reference to transportation, F. L. 

 Stevens {Phytopathology, 5 {1915), No. 2, pp. 108-110) .—Attention is called to 

 a number of questions relating to the development of diseases in fruits in trans- 

 portation. Of some of these troubles considerable information is at hand, but 

 It is stated that there is necessity for further investigations on those which 

 rapidly develop on wilting or old products under unsuitable conditions of tem- 

 perature and humidity. 



Report of the division of botany, H. T. GiJssow {Canada Expt. Farms 

 Rpts. 1914, pp. 831-849, pi. 1). — This report contains an account of adminis- 

 trative work in connection with the destructive insect and pest act and various 

 specific diseases, experimental work in plant-disease control, notes on investi- 

 gations in economic botany, and a report of St. Catharines field laboratory for 

 1913 (pp. 845-849), in which notes are given of a number of the more im- 

 portant diseases of apples, pears, quinces, cherries, peaches, and plums observed 

 during the season. 



Among the plant diseases investigated, considerable attention was paid to 

 those attacking the potato, and a description is given of a black heart of pota- 

 toes, which resembles that described by Bartholomew (E. S. R., 30, p. 149), but 

 which, in the present case, is attributed to frost injury. An account is also 

 given of apple canker and silver leaf of fruit trees. 



[Plant diseases in Southern Nigeria], C. O. Farquhaeson {Ann. Rpt. Agr. 

 Dept. South. Nigeria, 1913, pp. 41-55). — A presumably new root disease of 

 Para rubber trees at Calabar was said to be distinct from each of two others 

 due, respectively, to Polyporus lignosus {Fomes semitostus) and to Hymen- 

 ochwte noxia. 



Cocoa trees are affected near the forks by a trouble described as of unknown 

 causation. A pathogenic but undetermined fungus attacks also the maturing 

 pods. Thyridaria tarda is a very common saprophyte. 



Cotton leaf curl has been studied and the main conclusions therefrom are 

 given. The first-year hybrids of native American cotton were immune, resem- 

 bling in this the American parents. The disease is suspected to be identical 

 with mosaic disease of tobacco. An enzym may be the cause of the trouble. 



Cotton anthracnose {Colletotrichum gossypii) attacks most severely the native 

 cotton, American cotton and hybrids being almost entirely immune. A spotting 

 disease of bolls was ascribed to cool nights. A stem blackening disease is men- 

 tioned as of obscure origin. Ramularia areola and Vredo gossypii were very 

 common on American cotton, but neither afCected seriously native plants. 

 Spraying for the control of cotton diseases is impracticable, and careful selec- 

 tion of seed from immune plants and government seed control are suggested. 



Fungus disease of peanuts {Cercospora personata) was somewhat serious. 

 Its severity depended apparently upon the kind of weather prevalent during the 

 given season, possibly being conditioned by another disease of unknown but 

 probably physiological causation, which is described as suggesting cotton leaf 

 curl. 



Two rust fungi from the Royal Botanic Garden, Edinburgh, M. Wilson 

 {Notes Roy. Bot. Gard. Edinb., 8 {1914), No. 38, pp. 219-221, pis. 2).— The 

 author notes the discovery of Puccinia prostii attacking a bed of Tulipa sylves- 

 tris and doing considerable damage, the plants affected producing but few 

 flowers. The rust was probably present on the plants in 1913 or even earlier. 



Uromyccs scillarnm was found on leaves of Muscari polyanthum, which has 

 not hitherto been recorded as attacked by this rust. 



Both fungi are briefly discussed in these connections. 



