DISEASES OF PLANTS. 445 



ditions favoring rapid infection are a temperature of from 14 to 26° C, the 

 presence of 75 per cent or more of humidity, and little ventilation. 



A bibliography is appended. 



On the systematic position of Fusarium nivale as regards its higher fruit 

 form, E. ScHAFFNiT {My col. CentN., 2 (WIS), No. 5, pp. 253-258, figs. 2).— 

 The author reports a further study (E. S. R., 29, p. 47) of F. nivale, the 

 higher fruit form of which, otherwise called Nectria graminicola, is described 

 under the name Calonectria nivalis n. sp. It is said to present great multi- 

 formity as to devices for propagation, showing ascospores, conidia, chlamydo- 

 spores, and sclerotia. 



Concerning the sclerotia of Monilia, E. Voces (Ztschr. Pflanzenlcrank., 23 

 (WIS), No. 3, pp. 137-140).— To a previous communication (E. S. R., 26. p. 

 S49), the author adds that further study of certain sclerotia, found in associa- 

 tion with those of M. fructigena and assumed to belong thereto, has shown that 

 such sclerotia are sterile and in other ways different in behavior from those of 

 M. fructigena. 



Recent literature on fungus diseases of plants, L. H. Pammel {Trans. Iowa 

 Hort. Soc, //7 {1912), pp. 2Ui-22S). — Summaries are given of numerous recent 

 papers on plant diseases, mainly from American and Canadian sources. 



Diseases of plants in Iowa for 1912, L. H. Pammel {Trans. Iowa Hort. Soc, 

 //7 {1912), pp. 196-213, figs, i^).— The author states that during 1912 cultivated 

 plants were fairly free from fungus diseases. This is attributed to favorable 

 weather conditions, which are given in some detail for Ames, Iowa. The most 

 notable feature of the year is said to have been the spread and injury to apple 

 trees by the Illinois canker, apple blotch, and powdery mildew on the seedlings. 



Report of the imperial mycologist, E. J. Butler {Rpt. Agr. Research Inst, 

 and Col. Pusa [India], 1911-12, pp. 54-64)- — Besides accounts of other work 

 of the institute, reports are made of plant investigations completed in 1911 

 and 1912, or now in progress or in contemplation. 



The ufra rice disease of eastern Bengal is said to have increased in violence, 

 and it is claimed that recent investigations point to a nematode, Tylenchus sp., 

 as the probable cause of the trouble. An unsuccessful attempt to trace by 

 field inoculations the life history of the " false " smut of rice due to TJstila- 

 ginoidea virens is being repeated. 



Rhizoctonia solani is reported as a root rot on potatoes at Bankapur; on 

 jute, peanut, and cowpea at Pusa; on sesame at Surat; and on seedling cotton 

 at Cawnpore, this last attack being claimed to be identical with sore shin in 

 Egypt and damping off in America. R. solani is suspected to form biologic 

 races corresponding with its various hosts. A second Rhizoctonia, found on pea- 

 nut and cowpea, was examined, the study resulting in the retention therefor of 

 the name R. violacea. In the difficult work of combating Rhizoctonia, a dress- 

 ing of naphthalin was found beneficial in case of cotton. Carbolic acid proved 

 helpful but expensive. Cereals appear to be immune to Rhizoctonia and their 

 employment in rotation is suggested. 



For the first time in some years a severe attack of wheat rust is reported 

 in the Central Provinces and elsewhere, notably in Rajputana. Most of the 

 damage was caused by orange rust {Puceinia triticina) and black rust (P. 

 graminis). yellow rust (P. glumnrum) being much less common. Orange 

 rust has recently much extended its territory. 



Phytophthora colocasiw, which attacks kachu {Colocasia antiquorum), was 

 studied and is to be reported on later. The saprophytic culture of another 

 species of Phytophthora which attacks the castor bean plant was accom- 

 plished. P. infestans was found attacking potatoes and tomatoes at Jorhat 



