DISEASES OF PLANTS. 649 



Tomato diseases, G. E. Stone (Massachusetts Sta. Bid. 138, pp. 32, figs. 9). — 

 The principal portion of this bulletin is taken tip with a discussion of the blos- 

 som end rot of tomatoes, and an account given of experiments for its control. 



The different theories regarding the cause of this disease are summarized., 

 and the author states that his observations on the particular organism causing 

 the rot confirm those of Miss Smith to the effect that the disease is of bacterial 

 origin, as previously mentioned (E. S. R., 19, p. 49). 



Soil moisture was found to be an important factor in the control of the 

 blossom end rot in the greenhouse, but there were many other factors, such as 

 light, transportation, plant food, etc., which played an important role in its 

 occurrence. The observations of the author on the use of Bordeaux mixture for 

 the control of this disease have not been encouraging. His experiments indi- 

 cated that subirrigation greatly reduced the percentage of blossom end rot as 

 compared with top-watered plants and that a greater proportion of tomatoes 

 were affected in bright sunshine than where the plants were shaded. 



Notes are given on a number of other diseases of the tomato, among them 

 timber rot (Sclerotinia Ubertiana) , tomato scab (Cladosporiurn fulvum), sleep- 

 ing disease or wilt (Fusarium lycopersici) , downy mildew (Phytophthora infcs- 

 tans), anthracnose {Colletotrichum sp.), leaf blight (Cylindrosporium sp.), leaf 

 blight (Scptorin sp.), leaf mold (Alternaria solani), blight (Bacillus sola- 

 nacearnm), nematodes (Heterodcra radicicola), and surface molds. 



The effect of Gymnosporangium upon the transpiration and photosynthesis 

 of apple leaves, H. S. Reed and J. S. Cooley (Ahs. in Science, n. scr., 35 

 (1912), No. 891, p. 155). — In connection with pathological studies, the authors 

 determined the water elimination and carbon dioxid consumption of healthy 

 and rusted apple leaves of the varieties York Imperial ajid Ben Davis. Trans- 

 piration was measured on twigs on the trees and determined in grams per 

 square centimeter per hour. 



An average of 5 tests of Ben Davis apple leaves showed that in rusted leaves 

 the water elimination was about 50 per cent of that from healthy leaves on the 

 same trees. For determining the rate of photosynthesis Ganong's photosyn- 

 thometer was used, and the diseased leaves showed marked diminution in power 

 to consume carbon dioxid. 



The history and cause of the coconut bud rot, J. R. Johnston (U. 8. Dept. 

 Agr., Bur. Plant Indus. Bui. 228, pp. 175, pis. U, figs. iO).— This bulletin deals 

 with a destructive and widespread disease of coconuts, which is said to have 

 been known in Cuba for more than 30 years and also occurs in Jamaica, British 

 Guiana, Trinidad, British Honduras, and elsewhere. 



The author has conducted an investigation covering a period of about 4 years 

 on the nature and cause of this disease, a preliminary account of which has 

 been given elsewhere (E. S. R., 25, p. 552). Repeated inoculation experiments 

 have showTi that the disease is of bacterial origin, and the organism seems to 

 be identical with Bacillus coll. Inoculations into coconut seedlings with B. coU 

 of animal origin have given rise to infections similar to inoculations with the 

 coconut organisms. 



A bacterial disease of vanilla, G. L. Pavarino (Atti R. Accad. Lined, Rend. 

 CI. Set. Fis., Mat. e Nat., 5. ser., 20 (1911), II, No. 3, pp. 161, 162; ahs. in Riv. 

 Patol. Teg., 5 (1911), No. 8, pp. 125, 126). — A description is given of a bacterial 

 disease of vanilla that appeared in the botanic garden of Pavia. It is char- 

 acterized by the appearance on the leaves of small, irregular spots of a pitch 

 black color. Later the leaves may become perforated through the disintegra- 

 tion of the diseased tissues. The author repeatedly produced the disease 

 through subepidermal inoculations with the bacteria isolated from diseased 



