850 EXPERIMENT STATION RECORD, 



may be entirely resistant to attack throughout the season; that a particular 

 stocli may be throughout less resistant than another of the same variety; that 

 a stock or variety may be more sensitive under given conditions of development 

 (as age. soil, season, etc.) than another; and that stocks of the same variety 

 and even individual plants may show fluctuations as to sensitivity which appear 

 to depend rather upon the state of the natural defenses of the plant than upon 

 intensity of attack or other conditions. Some plants, it is said, are completely 

 resistant while very young, later showing resistance or sensitivity according 

 to certain circumstances, and still later, usually in August, showing suscepti- 

 bility continuing throughout the season. Late pruning with a view to retard- 

 ing the rather forward growth of 1912 is said to have favored mildew attack. 

 Kelative resistance as evidenced by a smaller proportion of surface attack 

 and absolute resistance as shown by complete immunity appear to be phenomena 

 of the same order, differing only in degree, being determined largely by the 

 conditions of the vegetative medium (such as age of organ or of stock, their 

 situation as regards moisture, etc.) and possibly to a certain extent by root 

 formation. 



An outbreak of mildew, M. Bailly {Rev. Vit., 39 (1913), No. 1019, pp. 876- 

 878, figs. 2). — Observations made by the author on downy mildew in Burgundy, 

 Champagne, and Loire, are said to lead to the conclusion that atmospheric con- 

 ditions of a general nature are probably in causal association with these attacks. 

 Precise data reg'arding- an attack of mildew, LaBeegeeie (Rev. Vit., 40 

 (1913), No. 1021, pp. 55, 56).— The author claims that observations made on' the 

 differences in degrees of attack resulting in a vineyard in blossom which was 

 sprayed partly before and pai'tly during a fine rain blowing from the south 

 enabled him to ascertain the exact hour of its infection by downy mildew. The 

 parts sprayed before the rain began were almost entirely free from mildew, 

 while the portions treated during its progress were heavily attacked and some 

 not treated at all showed almost a total loss of crop. Fourteen days were 

 required for the development of the fungus. 



Treatments for Oidium of grapevines, A. Thouret and J. L. Vidal (Rev. 

 Vit., 39 (1913), No. 1016, pp. 798, 795).— Formulas for fungicides are given, also 

 directions as to times and methods of their application. 



Wetting- power of fung-icidal mixtures, V. Vermorel and F. Dantony (Rev. 

 Vit., 39 (1913), No. 1015, pp. 759, 760).— In continuance of previous reports 

 (E. S. R., 27, p. 548; 29, p. 451), the authors state that all copper sprays 

 may be effectively and economically rendered adherent for grapevines by the 

 addition of 1 per cent of gelatin in the case of an acid reaction and of 2 per 

 cent casein in alkaline sprays. 



A spreading" and adherent form of Bordeaux mixture, J. Chauztt (Rev. 

 Vit., 39 (1913), No. 1015, pp. 764-766).— It is stated that the addition of casein 

 to Bordeaux mixture as recommended by Vermorel and Dantony (see above) 

 renders it especially adherent ; that the casein does not enter into combination 

 with the copper or cau.se it to take an insoluble form; that the copper com- 

 pound retains its strength and its full efficacy, being simply held to the leaf, 

 shoot, or berry as by a paste; and that in addition the casein confers upon the 

 fungicide a greater spreading capacity and a higher surface viscosity. 



Prevention and treatment of American gooseberry mildew, L. Hiltnee and 



KoRFF (Prakt. Bl. Pflanzenbau u. Schutz, n. ,^cr., 11 (1913), No. 6, pp. 73-77). 



A 3 years' course of treatment with sprays and fertilizers, particulars of which 

 are given, apparently freed severely infected plants from American gooseberry 

 mildew. 



