DISEASES OF PLANTS. 247 



o7 (toon). Xo. 11. pp. 29G-29H). — Studies were made of 25 varieties of potatoes 

 in wliicli the effect of cultural methods and different applications of fertilizers 

 on leaf curl and bacterial rin;;; disease was investigated. Tubers were planted 

 at different dei»tlis, large and small whole tubers and cuttings were compared, 

 and the relative effect of stable manure together with other fertilizers, large 

 applications of nitrate of soda, and the addition of lime were all tested. 



The effect of the different treatments on the diseases could not be definitely 

 stated, as many of the varieties differed widely in susceptibility and probably 

 in the amount of their previous infection. T^nusual depth of planting, either 

 too deep or too shallow, was found to be unfavorable to the plants. In many 

 cases it was imi)ossible to demonstrate the presence of the organisms causing the 

 disease, but the author believes that the lowered yields indicated the occurrence 

 of the fungi or bacteria even when mici'oscopical and bacteriological means 

 failed to reveal their presence. 



The author is led to believe that these diseases of potatoes are of an enzymic 

 nature and that the fungi and bacteria are of secondary importance. 



Directions for spraying potatoes, .T. G. Milward {^V^sconsin Sta. Circ. 

 Inform. S, pp. 8. fifjs. 3). — According to the author the early blight often develops 

 rapidly in Wisconsin after August 1. Only the standard medium late and late 

 varieties are much benefited by spraying with Bordeaux mixture. It is recom- 

 mend(>d that not less than 4 applications be given and that the spraying begin 

 not later than August 1ft. Where potatoes are grown on fertile soil and the 

 vines have made a healthy growth the spraying will usually be followed with 

 good results, but on poor soil where the growth is scanty it will seldom be 

 found profitable. The cost of spraying any considerable area should not exceed 

 $.'^>.20 per acre. 



Directions i)reviously noted (II S. R.. 20. j). 948) are given for the prepara- 

 tion and aitplication of Bordeaux mixture and arsenicals, together with sugges- 

 tions (m spraying machinery. 



Observations concerning' the American gooseberry mildew, 1906—1908, 

 G. LiND (K. Landtbr. Alcad. Handl. ocJi Tidskr., Jf8 {1909), No. 1, pp. 33-51, 

 fig. 1). — The results of three years' work conducted by the horticultural depart- 

 ment of the experiment station at Albano, Sweden, are given, with conclusions as 

 to the best methods of controlling the disease. 



Apoplexy of grapevines, L. Ravaz (Prop. Apr. ct Tit. {En. VEftt -Centre'), 

 30 (1909), A'o. .'i5, pp. 57-'i-579. pi. 1. dr/nis. /,). — A description is given of a 

 disease of grapevines due to a fungus, probably PoJiiporux'ignariu!^. Old vines 

 seem most sul^ject to the disease, and wlien cut into, the trunks are more or 

 less filled with matted masses of the fungus mycelium. Considerable loss is 

 reported in the Mediterranean region due to this cause. 



If the stock is not badly affected it is recommended that the diseased tissues 

 be cut out and the wounds covered with tar. When the fungus has severely 

 attacked the vines the diseased specimens should be entirely destroyed. 



Treatment for powdery mildew, G. CiiArPAz (Prog. Agr. et Vit. (Ed. VEnt- 

 Crntre), 30 (1909), Xo. 18, pp. 532-536. pi. 7).— For the prevention of powdery 

 mildew of grapes the author recommends mixed treatments as being efficient 

 and saving of labor. Sulphur may be combined with some of the copper solu- 

 tions for the first, third, and subsequent applications. For the second applica- 

 tion it is suggested that sulphur alone should be used and that it should be 

 apiilied just before the flowering of the grapes begins. By following this plan 

 both powdery and downy mildew may be combated at a considerable saving of 

 labor. 



Grape spraying experiments in Michigan, 1907-8, C. L. Shear and L. A. 

 Hawkins (Michigan Sta. Spec. Bui. .'f9, pp. 3-16, figs. 6).— This is a detailed 



