452 EXPERIMENT STATION RECORD. 



including employment of resistant stocks named, close in preference to wide 

 planting, and replanting with stocks fi-om roncet free localities. 



Court-noue associated with acariose in Swiss vineyards, H. Faes (Vie Agr. 

 et Rurale, 2 (1918), No. 27, pp. IJt-ll, fig- i).— Claiming that coiirt-nou6 of 

 grapevines, associated with general or physiological conditions in France, as 

 held by Ravaz (E. S. R., 29, p. 551), and in Italy, according to Pantanelli 

 (E. S. R., 28, p. 851), is due in Switzerland and Austria to the presence of an 

 acarid (Phyllocoptes vitis), previously described in connection with vine injury 

 (E. S. R., 24, p. 168), the author suggests the application in February or March 

 of alkaline polysulphid in 3 per cent solution. 



Studies on grape downy mildew, G. de IstvAnffi and G. Palinkas {Ann. 

 Inst. Cent. Amp^ol. Roy. Hongrois, ^ (1913), pp. 125, pis. 9, figs. 2; ahs. in 

 Oard. Chron., 3. ser., 54 {1913), No. 1046, p. 402).— This is a fuller account of 

 studies pursued for several years and in part already reported (E. S. R., 

 29, p. 350). It deals in considerable detail with the relations between plant 

 and parasite, discussing also some points still under investigation. 



It is stated that the germ tube enters by the stoma, forming beneath a 

 secondary spore, which throws out branching filaments. The oil spots are 

 centers of infection and are due to the presence of mycelium in and around 

 the stomata. In the leaf the hyphse appear more slender in dry weather. The 

 incubation period depends upon temperature and weather. It may be shortened 

 by hot, rainy weather, with absence of the oil spots. The form and size of the 

 latter also show a relation to the age of the leaves. At 6 to 8° C. the conidia 

 are said to retain their vitality for from 3 to 8 weeks. Infection occurs more 

 readily on the lower surface of the leaf. The receptivity to infection bears 

 some relation to substomatal vapor tension, to cell turgor, and to chemical com- 

 position of the cell sap. Rain, fog, and dew favor infection. 



A classified bibliography is given. 



Studies on grape downy mildew, G. de Istvanffi and G. PalinkXs {Rev. 

 Vit., 40 {1913), Nos. 1036, pp. 481-484; 1031, pp. 509-513; 1038, pp. 540-543).— 

 This is a more detailed discussion than that previously given (E. S. R., 29, p. 

 350), and deals with the development of Plasmopara viticola in the different 

 organs and the utilization of the incubation period for preventive treatment. 



Becent researches on grape mildew (Plasmopara viticola), G. de Istvanffi 

 and PixiNKAs {Internat. Inst. Agr. [Rome], Mo. Bui. Agr. Intel, and Plant 

 Diseases, 4 {1913), No. 10, pp. 1651-1655). —This gives briefly the substance of 

 the communications above noted from other sources. 



Red scald of grapes, II, H. Miilleb-Thurgatj {Centhl. Bakt. [etc.], 2. AM., 

 38 {1913), No. 21-25, pp. 586-621, pi. i).— Reporting further studies (E. S. R., 

 28, p. 55) on Pseudopeziza tracheiphila, the cause of red scald of grape leaves, 

 the author states that the fungus can live through the winter in dead leaves 

 and develop therefrom in the spring. It probably does not invade the shoots, 

 but the hyphse enter the leaf from either side during periods of moderate dry- 

 ness and follow the vascular bundles. The author recommends as preventive 

 or remedial measures the destruction of fallen or diseased leaves, improvement 

 in physical conditions and fertility of the soil, the planting of resistant varie- 

 ties, and spraying with Bordeaux mixture. 



Some diseases of pecans, F. V. Rand {U. S. Dept. Agr., Jour. Agr. Research, 

 1 {1914), No. 4, pp. 303-338, pis. 5, figs. 8). — A number of the more common 

 diseases of the pecan are described. Among these, nursery blight, due to Phyl- 

 losticta caryce, is said to be a serious disease of young trees but seldom found 

 in producing orchards. Brown leaf spot, caused by Cercospora fusca, is widely 



