750 EXPERIMENT STATION RECORD. 



overripe pears but only occasional causes of damage to apples. The optimum 

 temperature for growtli of the rot fungi appears generally to be above 18° C. 

 but growth continues until the freezing point is reached, although it is in general 

 checked by lowering temperature, different fungi showing considerable differ- 

 ences in this respect. 



Lime-sulphur wash for m.ildew of apple trees (Podosphaera oxycanthse), 

 J. Boll {Deut. Obstbau Zig., 1912, No. 3, pp. Ifi, h^). — The author notes that 

 while grape mildew (Oiclium tuckeri) appears to flourish best after heavy pre- 

 cipitation, the apple tree mildew seems to be favored by dry weather. For 

 control of both these fungi sulphur is recommended. 



In his experiments with lime-sulphur wash (1:20) after the outbreak had 

 become general, the first application stopped the spread, and a second killed 

 the remaining fungi, the dead leaves fell, and new leaves appeared. The author 

 recommends earlier spraying, perhaps late in April or early in May for the first, 

 and the latter part of June for the second, expressing further the opinion thar 

 the combat against this disease should reallj' be begun by appropriate means in 

 winter. 



Pourridie of the grape, G. Verge {Prog. Agr. et Vit. {Ed. VEst-Ccntre), 33 

 {1912), No. 5, pp. 132-136, pi. 1). — This disease, which has been long known in 

 Europe, is said to affect not only grapes but also fruit and forest trees, and is 

 known to occur iu France, Algeria, Italy, Switzerland, Austria, and Greece. 

 The cause of tlie disease is attributed to several of the higher fungi, among 

 them Agarimis melleus, DenwtopJiora necatrix, Rocsleria hypogca, and sometimes 

 PsathyreUa ampelina. The fungus spreads by means of rhizomorphs through the 

 soil, and for its control the author suggests digging deep trenches about the 

 affected plants so as to check the distribution of the mycelium in the soil. 



The treatment of downy mildew, C. Caors {Prog. Agr. et Vit. {Ed. VEst- 

 Centre), 33 {1912), No. 5, pp. IJfO, U/l). — The author reports the successful 

 treatment for a number of years of vineyards against attacks of downy mildew 

 by an early spraying of the vines, taking particular care to wet the lower sur- 

 faces of the lower leaves, upon which he thinks the first attack is made by the 

 winter spores being dashed upon them by rain. After the first spraying subse- 

 quent ones may be applied to the upper surfaces of the leaves, where most ^)f 

 the couidia find lodgment. 



On the chemistry of the higher fungi. — VII, Raspberry root rot fungus 

 (Hypholoma fasciculare), J. Zellner {Monatsh. Chem., 32 {1911), No. 10, 

 pp. 1051-1063) . — This is a continuation of previous reports (E. S. R., 24, p. 140) 

 and gives the results of an examination made by the author on the chemical 

 composition of this fungus. 



Nematodes on the roots of coffee trees, O. Tellez {Hacienda, 7 {1912), Nos. 4, 

 pp. 119-121, figs, .'i; 5. pp. lJf7, l-'i8, fig. 1). — A description is given of the at- 

 tacks of nematodes on the roots of coffee, and an account presented of ex- 

 periments with a number of different preparations for their control. Among 

 the substances tested were calcium carbid, various alkaline sulpho-carbonates, 

 carbon bisulphid, soap mixtures, petroleum, and tobacco.- 



The best results appear to have been obtained with calcium carbid. Eighty 

 gm. of this substance was divided and placed in holes about 3 cm. iu diameter 

 and 25 cm. deep, situated at a distance from the trunk equal to about the 

 length of the lower branches. 



Hollyhock disease, G. Webb {Gard. Chron., 3. ser., 50 {1911), No. 1288, 

 p. 174)- — Tbe author describes the successful treatment of hollyhocks against 

 attacks of the rust {Puccinia mulvacearum) by the application of a powder 

 which consisted of 1 bui of slaked lime, 1 bu. of soot, 4 lbs. of flowers of 

 sulphur, and 2 oz. of finely powdered sulphate of copper. This mixture should 

 be passed through a fine sieve and the plants dusted with the powder 3 or 4 



