DISEASES OF PLANTS. 251 



The downy mildew in 1908, II. Faes (Terrc Vaud., 1 {1909), No. 9, pp. 

 S5-87). — This is a discussion of the prepai'atiou of various sprays for combating 

 the grape mildew and the results obtained from conducting a series of experi- 

 ments in which the following sprays were used: Bordeaux mixture with 2 

 per cent coi)[ter sulphate, Bordeaux with 1 per cent copper sulphate, soda Bor- 

 deaux, soda Bordeaux and sulphur, oxychlorid of copper, sulphate of copper (1 

 per cent neutralized directly with 1 per cent of alkaline polysulphid), and 

 Reflorit, a trade compound. Three applications were made of each at intervals 

 of 15 days. 



The 1 and 2 per cent Bordeaux mixtures had the same effect in controlling 

 the mildew, as only a trace of the fungus could be found on the leaves, while the 

 yields were 313.46 and 301.7 liters per plat, respectively. The oxychlorid of 

 sulphur treatment was nearly as effective in controlling the fungus as the Bor- 

 deaux mixture, while the yield was 310.6(5 liters per plat. The sulphate of cop- 

 per and alkaline polysulphid was decidedly inferior to these sprays, both in 

 controlling the fungus and in the size of the yield, which was only 2ir).r)l liters, 

 while the Reflorit was poorest of all, as both the leaves and the fruit were 

 attacked on the plats treated with this spray and the yield was only 194.14 liters. 



Lathraea clandestina on the grapevine, P. Marsais (Rev. Vit., 33 (1910). 

 No. S4-'i. pp. 169-176, pi. 1, flfis. 9).— In a previous article (E. S. R., 21, p. 345), 

 the parasitism of L. chntdcstina on the grapevine is pointed out. The present 

 author adds to the information regarding this pest, giving an account of its life 

 history, parasitism, biology, and anatomy. 



The biology of Plasmopara viticola, W. Ruhland and F. C. von Faber 

 (Mitt. K. Biol. Anst. Land ii. Forstw., 1909, No. 8, pp. 19-21).— The results of 

 experiments on the germination, infection, and incubation periods of this fungus 

 are given. 



It was found that out of 51 inoculations of conidia on the upper surface of 

 the leaf only one infection was produced, while of 48 inoculations on the lower 

 leaf surface not less than 38 were effective. This would indicate that spraying 

 the upper surface of the leaves in combating this disease is practically worth- 

 less. 



The incubation period for the conidia, even under the most favorable condi- 

 tions, was found to be at least 5 days and often ranged from 10 to 20 days. 



The root rot of cofiEee in Guadeloupe, N. Patouillard {Jour. Agr. Trop., 

 10 {1910), No. lO-'f, pp. 58, 59). — A brief description is given of a root rot of 

 coffee, which can be recognized by the appearance of a mat of mycelium on the 

 surface of the roots, which also penetrates into the bark. Trees badly attacked 

 show the taproot lacking rootlets, while in other cases the rootlets are decorti- 

 cated to their extremities. In the absence of any fruiting bodies it is impossible 

 to determine definitely the fungus causing this trouble, but it is believed to be 

 a species of either Rosellinia or Dematophora. It has been found that in 

 Guadeloupe the same fungus attacks trees used as shade and from them may 

 spread to the coffee. 



As a means for preventing the spread of this disease it is recommended that 

 infected trees be dug up and their roots completely removed and burned in the 

 hole from which they were dug. Care should be exercised to prevent too much 

 moisture about trees. As the use of carbon bisulphid has given good results 

 with the root rot of grapes, it is thought that probably this method of treatment 

 would also be efficient. 



Coniophora cerebella as a timber destroyer, E. Sciiaffnit {Ccntbl. BaJct. 

 [fie], 2. AM., 26 {1910), No. 10-12, pp. 352-356, pi. i ) .—Attention is called to 

 the wood-destroying properties of this fungus, which like species of Meruliua 

 and Polyporus produces a form of dry rot in timber. 



