DISEASES OF PLANTS, 547 



For the downy mildew 3 treatments with liquid fungicides followed by 2 with 

 powdered sulphates, for the black rot 4 treatments with liquid fungicides and 2 

 with powdered sulphates, and for the powdery mildew 2 treatments with pure 

 sulphur combined with the necessary complementary treatments with powdered 

 sulphates are said to be sufficient for the control of these diseases. The time 

 for the different applications will vary with atmospheric and other conditions. 

 The liquid fungicides recommended are Bordeaux mixture, Burgundy mixture, 

 Bordeaux mixture to which molasses is added to improve its adhesiveness, and 

 copper acetate solutions, formulas for the preparation of which are given. In 

 choosing the powders there is said to be but little difference, except that the 

 first-named should should contain at least 50 per cent sulphur. 



Infection of the grape by downy mildew, L. Ravaz and G. Verge (Prog. 

 Agr. ct Vit. {Ed. VEnl-Ccntre), 33 (1912), No. 19, pp. 581-584).— In continuation 

 of previous work (E. S. R., 27, p. 49), the authors investigated the susceptibility 

 of flowers, fruits, pedicels, peduncles, and shoots of several varieties of grape 

 to mildew attack. They conclude from these that the fruit stems are less open 

 to infection than are the leaves, that the flowers are most liable to attack, and 

 that the berries were not contaminated in any case. Density of tissue and 

 rarity of stomata are supposed to be in a measure protective in this connection. 



The influence of weather on Peronospora disease of grape, R. Gerneck 

 (Weinbau u. Wcinliandcl, 30 {1912), No. 18, pp. 199, 200). — A short discussion 

 is given of the conditions favoring attacks by this disease as illustrated by 

 observations of recent years. Such conditions are said to be heavy rainfall, 

 heat, and shade. Storms furnish all these conditions at once, and have been 

 followed bj' notable outbreaks. 



A new parasite of the grape, L. Planchon {Prog. Agr. et Vit. {Ed. VEst- 

 Centre), 33 {1912), No. 22, pp. 676-686, i^. 1. figs. 7).— A description is given 

 of Osyrifi alha, a phanerogamic plant which is reported growing as a parasite 

 or hemiparasite on the roots of grapes in parts of France. 



A mulberry disease, R. Avekna-Sacca {BoL Agr. [Sao Paulo], 12. ser., 1911, 

 No. 9-10, pp. 121-1. 'fO, figs. 8). — An account is given of the symptoms and spread 

 of a leaf spot disease which is ascribed by the author to Sphccrella moricola and 

 is said to have been confused with that due to other organisms, as in case of 

 mulberry bacteriosis. A discussion is given of allied fungi, of conditions favor- 

 able to spread of this disease, of varieties of mulberry found to be resistant 

 thereto, and of preventive or remedial measures, as sulphate of copper and 

 Bordeaux mixture. -A brief bibliography is appended. 



Further studies on the pecan rust, F. Y. Rand {A'bs. in Science, n. ser., 35 

 {1912). No. 913, p. 1004).— In a preliminary report (E. S. R., 26, p. 56) the 

 author described the fungus causing the leaf disease of pecans as MycospliwreUa 

 convexula. Since that time additional studies have been made, and in the 

 course of 11 years' growth in cultures strains originally producing a majority 

 of apparently two-celled ascospores have changed until now most of the asco- 

 spores are distinctly nonseptate. Furthermore, a typical Gloeosporium form has 

 developed in culture and has also been obtained from the host. Inoculations 

 with cultures which originated from single ascospores made on Jonathan and 

 Yellow Newton apples gave a decay similar to the bitter rot, with the produc- 

 tion of conidia and immature perithecia on the latter. 



From the studies thus far made it appears that the fungus is closely related 

 to if not identical with Glomerella rufomacuhms, and that it is not a very 

 active parasite on the pecan. 



A bacterial disease of Aster chinensis, G. L. Pavarino (Atti R. Accad. 

 Lincei, Rend. CI. Sci. Fis., Mat. e Nat., 5. ser., 21 {1912), I, No. 8, pp. 5U-546).— 

 The author describes a disease of asters due to Bacillus asteracearum n. sp. 



