DISEASES OF PLANTS. 551 



Notes on the wintering of powdery mildew, G. de Istvanffi (Buh Inst. 

 Vent. AnipcIoL Roy. JIuiujrois, J (W06), pp. D-IJ [pub. J!)OS]). — A resume is 

 given of investigations begun in 1903 on the wintering of the powdery mildew. 



The Oidium form was found to persist in buds and on tendrils, and for its 

 treatment the author recounneuds a late autumn spraying of the vines, the 

 collection and destruction of the tendrils, and in the spring the removal of 

 the young shoots which show the first spring attack. The spring treatment 

 is to be suppleuiontcd by powdering with sulphur or a mixture with bisulphite 

 of soda. This comi>ound is said to act at a lower temperature than sulphur, 

 which, it is said, is not etticient when the temperature falls below 17° C. 



Experiments in the control of powdery mildew in the greenhouse, G. ue 

 Istvanffi {Bitl. Inst. Cent. Amp(ilol. Roy. Hongrois, 1 {1906), pp. I.'i, l'> [pub. 

 1908^). — A brief report is given of exi)erinients for the control of the powdery 

 mildew in graperies, in which the best results were obtained where a mixture 

 of bisulphite of soda and sulphur was used. One-tenth per cent picric acid 

 was without much effect and it badly burned the leaves. 



Experiments on combating mildew, A. Szigethi-Gyula and L. Dupuis {Bui. 

 Inst. Cent. Ampelol. Roy. Ilonyrois, 1 {1906), pp. 13, 1', [pub. 1908]).— A brief 

 report is given of experiments in which about 1,000 grapevines were treated 

 for the prevention of mildew. The treatment included spraying and dusting 

 with fungicides before the opening of the buds, or the application of fungicides 

 later in the season. The preliminary treatment consisted of washing the vines 

 with solutions of sulphate of copper, bisulphite of sodium, neutral copper ace- 

 tate, and two trade preparations known as "Antispora " and " Result." The 

 later sprayings were with Bordeaux mixture made by different formulas, Anti- 

 spora, and Result. 



The best results obtained were where Bordeaux mixture was used, and Anti- 

 spora and Result were without much value for the control of the disease. 

 Where the vines were dusted with neutral copper acetate the leaves remained 

 green until the time they fell from the vines, while the check plants were 

 completely defoliated by the beginning of September. 



Experiments on the treatment of chlorosis of grapes, J. Bernatzky {BuI. 

 Inst. Cent. Ampelol. Roy. Hongrois, 1 {1906), pp. 8, 9 [pub. 1908]).— A summary 

 is given of experiments for the treatment of chlorosis. 



The author found that with the addition of 8 to 10 parts of carbonate of lime 

 or carbonate of magnesium in 1,000 parts of a normal culture medium chlorosis 

 would be produced in grapes, the leaves showing the characteristic symptoms 

 and the roots suffering in their development. The oxids of lime and magnesium 

 and the phosphate of sodium and tribasic potash produced similar effects even 

 when used in 5 parts per thousand. Smaller quantities of carbonates had no 

 effect on the production of the disease. 



In treating chlorosis it was found that by neutralizing the medium with 

 some form of acid the disease was prevented. This was particularly true when 

 sulphate of iron, or better, the sesquichlorid of iron was used. If the nutrient 

 solution did not contain iron, but was neutral or slightly acid, plants could 

 remain in it for from 2 to 3 months without showing any indication of disease. 

 The author says that in field treatment it is only necessary to neutralize the 

 alkaline soils to secure immunity from the disease. 



The falling of the flowers of grapes, E. I'antanelli {Atti R. Aeead. Lincei, 

 Rend. CI. Hci. Fis., Mat. e Nat., 5. ser., 18 {1909), I, No. 8, pp. .',06-Jitl ; abs. in 

 Jour. Chem. Soc. [London], 96 {1909), No. .560, II, p. ,1/.^).— The author has 

 investigated a case of the falling of flowers from grapevines, and finds that 



