1920] DISEASES OF PLANTS. 151 



aiul liito hliglit ; siicli t'ahbnjrc disciises ;is lilacklcj,', black ro(, aii<l yollows; 

 toiiiat<) diseases, chief of which is tlie wilt caused by a fuiijius similar to that 

 causiiifi; cabbajje yellows; cucumber and melon diseases, particularly bacterial 

 wilt; bean diseases, of which anthracnose is the most important; and asi)ai-a,tius 

 nist, the chief protection against which is to grow rust-proof varieties. 



Plant disease investigations, J. B. S. Norton et al. {-Maryland Sta. Rpt. 

 1919, pp. XLVIII-LII). — Among the investigations reported upon are a study 

 of tomato blight due to Septoria lycopersici, Sclerotinia fruit rot, Fusarium 

 wilt resistant tomatoes, control of leaf blight of tomato, some studies on dis- 

 eases of seeds, the life history of IMycosjihserella, etc. 



In a study of the tomato blight, it was found that the conidial form of 

 S. liicopersici was able to withstand temperatures near zero, and was present 

 on tomato waste in the spring. ■ High temperature and humidity were found 

 to favor infection. Certain varieties of tomatoes in the seedling stage, at 

 least, were found more susceptible than others to infection. Many other solan- 

 aceous plants, especially horse nettle, eggplant, and potato are subject to attack 

 by this fungus. 



In investigations with Sclerotinia fruit rot, the relative abundance of blossom 

 blight and the apothecial stage of the fungus were determined. It was found 

 that the petals and other parts of the flowers affected by the ascospores may 

 carry the disease along to the stage wh,en injured or ripening fruits may be 

 attacked. 



In an effort to secure strains of canning tomatoes resistant to the wilt 

 fungus, strains of good yield and quality have b^en developed. These are being 

 given rather ^^■ide planting throughout the State. 



For the control of the leaf blight of tomato, the author reconiiiiends the use of 

 Bordeaux mixture to which resin fish oil soap was added as a sticker. In 

 order to avoid the mechanical injury to plants under ordinary conditions, it is 

 recoujmended that the row^s be 6 ft. apart and the plants spaced 3 ft. apart in 

 the row. 



Report of the microbiologist, 1917-18, S. F. Ashby {Ann. Rpt. Bd. Agr. 

 and Dept. Pub. Gard. and Plantations Jamaica, 1918, pp. 33, 3-'f). — I'anama 

 disease (wilt) has been found in new areas. Studies on banana soils reveal the 

 presence of two s])ecies of Fusarium. It is stated, however, that a form abso- 

 lutely identical with that producing the disease as regards such characters as 

 growth, reproduction, and odor has not yet been found in the soil. 



Coconut bud rot, causing loss in the eastern parishes, is described. A fungus 

 resembling Phytophthora (possibly Pythium palmivorum, said to cause a coco- 

 nut bud rot in India) has been isolated from the heartleaf spots, from water- 

 soaked tissue of the limb of the heartleaf, and from the husks of fully grown 

 but inunature nuts. Another fungus, a Phytophthora. has been isolated from 

 different parts of the tree. 



Leaf-bitten diseases have been extensively treated with promising results in 

 spite of hurricane injury. 



Gall disease of sweet potatoes, due apparently to Albngo sp., showed further 

 extension. The disease of pimento associated Vith fire blight symptoms was 

 again observed. The causal fungus was isolated and yielded a perfect fruiting 

 stage, proving its identity with RoatrcUa coffar. A rot of yams was found to be 

 caused by Cortirinm vayuin mlani. Potato late blight (I'ln/tophlliora infcstans) 

 appeai-ed at si'veral points. Honeycomb defect of copra A\as found to be due to 

 Bacillus mcscntcriciis vuh/atini. The strain is markedly thermophilic, with- 

 standing LW° F. Sulphur fumes are preventive. 



r Report of the microbiolooist, 1918-19, S. F. Asiiisy {Ann. Rpt. Bd. A;/!: 

 d Dcpt. Pub. Gard, and Plantations Jamaica, 1919, p. 26). — Some evidence was 



