DISEASES OF PLANTS. 643 



Copper sprays, H. Fonzes-Diacon (Compt. Rend. Acad. Sci. [Paris], 160 

 (1915), No. 16, pp. 528-530). — The author summarizes his account of a study 

 carried out by himself on the comparative fungicidal values of copper sprays 

 with the claim that strongly acid mixtures are rich in tetracupric sulphate. 

 They also contain the components of that ingredient in addition to copper sul- 

 phate, and possess, therefore, a high fungicidal value, while the neutral mix- 

 tures contain less, and the alkaline preparations but little of that ingredient. 

 The alkaline preparations tend, moreover, to the formation of the less effective 

 compounds of copper. 



Bordeaux and Burgundy mixtures, H. Fonzes-Diacon {Prog. Agr. et. Vit. 

 (Ed. I'Est-Centre), 36 (1915), No. 18, pp. 416-419).— Directions and suggestions 

 are given regarding the preparation and use of spraying mixtures in accordance 

 with the data set forth by the author in the article above noted. 



Report of the botanist and plant pathologist, H. W. Bakee (South Caro- 

 lina Sta. Rpt. 1915, pp. 21-26). — A progress report is given on the various 

 projects, in plant diseases, conducted under the Adams fund, and continuing 

 previous work (E. S. R., 32, p. 543). 



Continued investigations on the effect of hot-water treatment of cotton seed 

 for the prevention of anthracnose have proved quite successful. In one field 

 of 12 acres only about 1 per cent of the bolls showed any injury at the end 

 of the season, while from the same seed, untreated, 15 per cent of the bolls 

 were destroyed. In a field where the same cotton was grown the previous 

 year, 45 per cent of the bolls were destroyed. In connection with this investi- 

 gation, it was found that the seed of different varieties of cotton varied in 

 respect to the temperature they could withstand, some varieties being killed at 

 72° C, while others stood a temperature of 76°. 



In addition to the hot-water treatment, some spraying experiments were 

 conducted in which Bordeaux mixture, lime sulphur, and bichlorid of mercury 

 were tested. The amount of anthracnose was so considerably reduced that it is 

 intended to repeat the experiment another season. It is not expected, however, 

 that spraying cotton will prove an economical method of preventing anthrac- 

 nose, it being considered applicable only as an additional means of securing 

 clean seed for planting. 



The investigation on the relations of moisture content and shedding of bolls 

 has been continued, and an attempt is being made to determine at what season 

 the cotton plant needs most water. The 20 pot plants worked with used con- 

 siderably the most water in August. Data are also being collected on the 

 time it takes cotton to mature in this climate, from 24 to 30 days elapsing from 

 the first appearance of the squares until the flowers open, and from 55 to 65 

 days from blooming to the opening of the bolls. 



On the bacterial diseases of cotton, the work has been conducted by F. M. 

 Rolfs, who has made a study of the angular leaf spot caused by Bacterium 

 malvacearum. It is reported that seed treatment and spraying tests gave some 

 very satisfactory results. 



Among the miscellaneous notes given, the author reports the serious loss 

 caused to corn by Physoderma sp., the presence of a species of Sclerotinia on 

 alfalfa, and the work on cotton and cowpea wilt and root knot carried on in 

 cooperation with this Department. 



Administration report of the government mycologist for 1913—14, W. 

 McRae (Rpt. Dept. Agr. Madras, 1913-14, pp. 49, 50).— It is stated that the 

 bud rot of coconut palms found late in the previous year in Malabar has been 

 shown to be caused by Pythium palmivorum. The characteristic signs of bud 

 rot have been obtained by inoculation of young palmyra palms with the fungus 

 from diseased older trees. 



