746 EXPERIMENT STATION RECORD. 



Methods used in fighting the peach yellows, E. Hutchins (Better Fruit, 

 5 {1910), A^o. 1, pp. 64, 6'.5).— The i-esults are given of a systematic weekly up- 

 rooting, cutting, and burning during three years of all trees showing evidence 

 of yellows, at the end of which time the disease was practically eradicated, and 

 the remainder of the trees were sound and vigorous. 



The mildew of the grape, L. Bottini (Prog. Agr. et Vit. (Ed. VEst-Gentre), 

 81 (1910). Ao. 26, pp. 180-1 S3). — In a studj' of the internal causes that produce 

 a difference of resistance in cei'tain varieties of grapes to the attacks of 

 Peronofepora, it was found that the leaves of a susceptible variety, when im- 

 mersed for 1 hour in the juice from a highly resistant variety and then inocu- 

 lated with the spores of Peronospora, were more resistant to the fungus than 

 untreated leaves. From this the author concludes that the juice or sap of the 

 highly resistant varieties is the cause of their greater immunity to the attacks 

 of the fungus. 



An eflB.cient spray against the grape mildew, V. Vermorel and E. Dantony 

 {Prog. Agr. et Vit. (Ed. VEst-Ccittrc), 31 (1910), No. 30, pp. 101, 102; abs. in 

 Rev. Vit., 34 (1910), No. 866, p. 71). — It is claimed that a spray comjwsed of 

 100 liters of water, 20 gm. of nitrate of silver, and 300 gm. of white soap has 

 pro\ed very valuable iu combating this fungus, being much superior to the cop- 

 per spi'ays used for comparison at the same time and with the same number of 

 applications. 



To prepare the spray, first dissolve the 20 gm. of nitrate of silver in 1 liter 

 of water and the 300 gm. of white soap (in powdered form) iu a few liters of 

 hot water, then pour the soap solution into 100 liters of water, and lastly, add 

 the silver nitrate solution and stir. 



The Oidium and a modified lime-sulphur spray, V. Thi^baut (Rev. Vit., 

 33 (1910), No. 862, pp. 691, 692).— The author states that since 1900 he has 

 used with complete success a modified lime-sulphur spray on his vineyard of 

 some 30.000 plants containing more than (JOO varieties, some of which are very 

 susceptible to the Oidium. and that since 11K)6 two treatments per season have 

 eomi)letely protected the foliage against this fungus. On some of the most sus- 

 ceptible varieties of grapes, however, the fruit has been attacked, to prevent 

 which a supplementary treatment of the inflorescence with lime sulphur alone 

 at the time of flowering has been used. 



To prepare the spray, slake one part by weight of good quicklime to a paste, 

 and while still hot add two parts by weight of sublimed sulphur, stirring thor- 

 oughly and rapidly with a wooden paddle until the mixture is sufficiently cool 

 to bear one's hand in it. Then add water little by little, stirring energetically, 

 until a semilicjuid, homogeneous, citron-colored paste is produced, which thickens 

 when cold, and. if covered up and stored in a cool place, will keep for a long 

 time. Now dissolve in water an amount of copper sulphate equal to the weight 

 of the sulphur used in the lime-sulphur paste, and add the lime-sulphur paste 

 to the sulphate solution, stirring vigorously until the resulting mixture is 

 neutralized, as shown bj'^ phenolp'hthalein paper. If properly done, the result 

 will be a very homogeneous mixture, which will not deposit sediment either in 

 the containing vessel or on the sprayer. 



The first application should be made with a 1 per cent solution of the lime- 

 sulphur-siilphate mixture when the young shoots are from G to S in. long. Dur- 

 ing the flowei'ing period the inflorescence alone should receive the lime-sulphur 

 mixture. Immediate! j after the flowering period there should be used a 1^ per 

 cent solution of the lime-sulphui"-sulphate mixture, and about the ripening i)eriod 

 another application of the same strength. 



