1918] DISEASES OF PLANTS. 351 



Pusa durinj^ the year 1915-16 was that of rice known as ufra in eastern Ben- 

 gal. The cause of this very destructive disease is a nematode {Tylcnchns 

 angustus) whicli hibernates in dry stubble, renewing its activity with high 

 atmospheric humidity and heavy rainfall and perishing after immersion for 

 some weeks in water or passing into a dormant state under dry conditions. 



Tokras, a parasitic species of Orobanche on tobacco, mustard, and cabbage, 

 were not controlled by the use of sodium nitrate. A study of Rhizoctonia by 

 Shaw (E. S. R., 35, p. 14S) has been continued. Studies have been prosecuted 

 on two local plantain diseases and the black thread disease of rubber. Other 

 diseases under investigation are a disease of sal trees ; wilts of cotton, sesamum, 

 gram, and chillies; and sclerotial diseases of jute and sugar cane. 



A new method of denling with the palmyra palm disease has proved effective. 

 It consists of very close scrutiny of all palms in a disease center and cutting 

 out and burning all diseased portions of the crown of affected trees. The 

 koleroga disease of the areca palm can be eradicated from isolated areas by 

 means of spraying. 



Black rot of coffee is checked by Bordeaux mixture, which also controls 

 brown blight of tea. Of the four smuts of sorghum present in Bombay, two 

 can be prevented by steeping the seed in copper sulphate. Studies have been 

 continued on fungi attacking tea roots and leaves. Poppy blight is epidemic 

 only under adverse climatic conditions and poor drainage. Certain varieties 

 appear to be almost inmume to the disease. 



Cryptog'ainic review for 1914 and report on leaf diseases of conifers, G. 

 Briosi (Bol. Min. Agr. e Indus., Com. ed Lavoro [Rotne'], Ser. B, 14 {1915), II, 

 No. 1-2, pp. 38-47; Afti 1st. Bot. R. Univ. Pavia, 2. ser., 16 (1916), pp. 285- 

 308). — This report, which is on the same general plan as that for 1913 (E. S. R.. 

 34, p. 539) gives an account of diseases of conifers, vines, cereals, fruits, forage, 

 garden, ornamental, industrial, and other plants ; scientific and miscellaneous 

 studies ; and some publications of recent issue. 



Cryptogamic review for 1915 with report on grain diseases, G. Briosi {Bol. 

 Min. Agr. e Indus., Com. cd Lavoro [Rome'i, Ser. B, 15 {1916), II, No. 5-8, pp. 

 11-26; abs. in Riv. Patol. Veg., 8 {1916), No. 10, pp. 197, 198).— This report, 

 which is on the same plan as that noted above, gives more particular attention 

 to grain diseases. 



Physoderma disease caused by P. zeag maydis {U. S. Dept. Agr., Bur. Plant 

 Indus., Plant Disease Bvh, 1917, Nos. 1, pp. 9, 10; 3, pp. 51, 52, fig. 1).—A brief 

 account is given of the occurrence and geographic distribution in the United 

 States of P. zca; maydis, which attacks corn. Its known distribution includes 

 the States of North Carolina, South Carolina, Georgia, Florida, Alabama, Mis- 

 sissippi, and Tennessee. 



The internal disease of cotton bolls, W. Nowell {Agr. News [Barbados] . I4 

 {1915), Nos. 344, P- 222; 345, pp. 238, 239).— The investigation of internal boll 

 diseases of cotton having reached a stage where it is considered as likely that 

 future research must follow entomological as well as mycological lines, the 

 author summarizes the history of this disease and opinions regarding its causa- 

 tion, citing more particularly the findings and views of Robson (E. S. R., 35, 

 p. 44) in tills connection. 



The general conclusion is that while the staining may be initiated by matter 

 issuing from punctures in the young seeds it is caused by infection with a for- 

 eign organism. In most cases this appears to be a .specific fungus (not yet 

 named), but infection is in some cases due to other fungi or to bacteria. 



The internal disease of cotton bolls, W. Nowell {Agr. News [Barbados], 15 

 {1916), No. 364, pp 126, i27).— Following up the information given In the 



