DISEASES OF PLANTS. (i87 



Observations show that potato plants dt-velojied from tubers which are nion^ or 

 less covered with sclerotia of this fungus usually liave their sul)terranean parts cov- 

 ered with a dark-ljrown cobweb-like mycelium. This covering frequently extends 

 up the green stems 1 to .'5 in., or more, above the ground, forming a thin layer of a 

 greenish-white color. This layer does not adhere firmly to the stem and cracks 

 easily when it becomes dry; conseijuently it disappears soon after the death of the 

 plant. The tip of the outermost branches of this layer produced spores. Thus far 

 inuT cultures of the fungus have not l)een directly obtained from the spores, but 

 cultures made from the hymenial layer invariably jiroduce a luxuriant growth of 

 Rhizoctonia. 



The character of the fungus agrees on the one hand with Cortlciinn ragum, and on 

 the other hand with Hypnochus sulani, and it is thought that probably these 2 species 

 may eventually ]irove to be the same. 



The formalin treatment for wheat and oat smut, R. K. Eeattie ( Washington 

 Sta. Bnl. 54, pi>. S). — The author estimates the losses in 1902 to the oat and wheat 

 harvest, in Washington, due to smut, at |2,500,000. Notes are given on various indi- 

 vidual losses, followed by a brief popular description of the smuts attacking the 

 cereals. 



Soaking the seed grain for a few minutes in copper-sulphate solutions is quite 

 extensively followed, but the investigations of the author show that the treatment 

 is not sufficiently prolonged. Instead of dipping the grain and allowing it to remain 

 in the solution from 5 to 20 minutes, as is the common practice, the author suggests 

 that the soaking should be for at least 12 hours. A better treatment, however, is 

 recommended in the substitution of formalin solution for the copper-sulphate solu- 

 tion. The method of treatment is described in detail. 



"Takeall" and "whiteheads" in wheat crops, W. L. Summers {Jour. Agr. 

 and Iiid. SoutJi AusfraUa, 7 {IDOS), No. 5, pp. 297-299). — Notes are given on the 

 disease of wheat which has been determined to be caused by the fungus Ophiobolus 

 gramini.s. This fungus has been the cause of considerable loss in various parts of the 

 country, and while in Europe it is said that the use of phosphates has been beneficial 

 in reducing the amount of disease, their use in Australia has not been followed with 

 a reduction of loss. The greatest benefit has been found by burning over the stubble 

 fields prior to plowing. 



TJredinous infection experiments in 1903, W. A. Kellerman {Jour. Mycol.,9 

 {1903), No. 68, pp. 225-238). — In continuation of experiments reported for 1902 

 (E. S. R., 14, p. 530), the author has carried on experiments with various species of 

 rusts (luring 1903, 22 species being used and 9 successful inoculations secured. As in 

 the former investigations, very early inoculations have proved advantageous in this 

 kind of investigation. 



The occurrence of Puccinia phragmitis in Nebraska, J. jNI. Bates {Jour. 

 Mycol., 9 {1903), No. 68, pp. 219, 220). — The author reports having found jecidia, 

 which proved to be Puccinia phragmitis on rhubarb in Nel)raska, ■\\hicli appears to 

 be a new host for this country. By subsequent investigations a number of species of 

 Rumcx were found affected in a similar way. 



Iietters on the diseases of plants, N. A. Cobb {Agr. Gaz. New South Wales, 14 

 {1903), No. 10, pj>. 955-9SG, figs. 31). — The author discusses ajiple canker, peach curl, 

 various diseases of citrus fruits, diseases of passion vines and walnuts, leaf curl of the 

 potato, and various root rots and timber rots. So far as known remedies are given 

 for these different pests. 



A method for rendering cucumber and tomato plants immune against 

 fungus parasites, (t. ^NIassee {Jour. Roy. Ilort. Soc. {^London'], 28 {1903), No. 1-2, 

 pp. 142-145) . — Cucumbers and tomatoes grown under glass are highly susceptible to 

 disea.se, the principal reasons for which are tlie soft foliage and the presence of fungi 



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