DISEASES OF PLANTS. 841 



nates In that way. The black rot is said to be due to Steriginatocysti^ nigra, 

 which affects the tobacco after it is harvested. A high moisture content and 

 high temperature in the curing house favor the development of this disease. 

 Practical methods for its control have been worked out which are based on the 

 regulation of the percentage of moisture in the leaf and conti'ol of temperature 

 during fermentation. 



In cooperation with C. L. Shear, of this Department, L. R. Jones has carried 

 on some investigations on the false blossom of cranberries, which is found to 

 be a physiological trouble due to unfavorable cultural conditions. The most 

 important factor for the elimination of this trouble is said to be proper drain- 

 age. Surveys made of cranberry diseases indicate that while other diseases are 

 present, none are serious that can not be controlled by spraying or other well- 

 recognized methods. 



Fungus diseases of plants, S. L. Ajrekae {Poona Agr. Col. Mag., 5 (1914), 

 No. 3, pp. 184-192). — ^As a preliminary account of plant diseases, brief descrip- 

 tions are given of millet smut, grapevine mildew, red rot in sugar cane, and 

 Koleroga disease of palms, together with suggestions for their control. 



Phytopathological report for 1913, E. Foex (Rev. Phytopath. AppL, 1 

 {1914), ^^os. 18-19, pp. 13-15; 20-21, pp. 17-23; 22-23, pp. 25-29).— Condensed 

 accounts are given of observations on diseases of cereals, tubers, forage plants, 

 vines, fruits, berries, pines, and oaks, with some remedies tested or proposed. 



Diseases of plants. — I, Herbaceous plants, B. Tomei {Malattie delle Piante. 

 Piante Erhacee. JJrhino, Italy, 1913, pt. 1, pp. 111). — This contains very brief 

 discussions of several diseases, with proposed I'emedies, of wheat, corn, vetch, 

 potato, tobacco, alfalfa, clover, sulla, and sainfoin. 



The introduction of model treatments of plant diseases in Posen and West 

 Prussia, R. Schandee (Mitt. Dcut. Landw. GeselL, 29 (1914), No. 21, 294-298).— 

 This is a brief outline of the proposed general plan and scope of operations 

 for the protection of economic plants from various diseases in this section. 



Some practical means of combating plant diseases as employed in Russia, 

 A. DE Jaczewski (1. Cong. Internat. Pathol. Compar^e [Paris], 1912, vol. 2, 

 Comp. Rend., pp. 948-955). — Among the results reported, it is claimed to have 

 been shown that the general requirements for a practical fungicide are best 

 fulfilled by a mixture of copper sulphate and alkaline polysnlphids, this proving 

 safe, cheap, and efficacious, as instanced by tests on Phyllosticta 'briardi on 

 apple trees, the proportion formerly used (0.5 per cent of each component) be- 

 ing found to be reducible to 0.2 per cent of the former and 0.3 per cent of the 

 lattei'. 



The immense damage formerly done by Bphwrotheca mors-uvw to gooseberry 

 has been greatly reduced by use of alkaline polysnlphids. The hot water treat- 

 ment for Ustilago hordei and U. tritici is thought to be limited in its beneficial 

 effect only by the present difficulty in securing the best conditions for its 

 employment. 



Heredity of disease in plants and Mendelism, L. Blaringhem (1. Cong. 

 Internat. Pathol. Compart^e [Paris}, 1912, vol. 1, Raps., pp. 250-312, figs. 12).— 

 This is a somewhat comprehensive discussion, dealing with different phases and 

 probable origins or causes of anomaly or disease in plants, including the influ- 

 ence of heredity and environment, as well as of parasitism. A bibliography is 

 appended. 



Tumors of roots and rootlets, O. Larcheb (1. Cong. Internat. Pathol. Com- 

 par6e [Paris], 1912, vol. 1, Raps., pp. 312-328). — This is a brief general treat- 

 ment as to tumors of underground portions of plants, as regards their external 

 characters, pathological anatomy, effects, etc., with a somewhat extensive bib- 

 liography of the subject. 



