DISEASES OF PLANTS. 145 



to have been attacked by disease. This variety has been subjected to severe 

 tests as to disease resistance for the past 10 years, but has never shown any 

 signs of disease. It produced no pollen until 1910, and was also sterile to all 

 pollen of other varieties, but by using its pollen on the varieties Factor and 

 Admiral, fertilization occurred and an abundance of good seed was obtained. 

 This immune variety is of excellent edible quality, and although the color of its 

 tubers and its low yield make it worthless as a commercial potato, its progeny 

 should develop some very valuable disease-resistant strains. 



The potato eelworm, S. B. Doten and P. P^bandsen (Nevada /S7«. Bui. 76, pp. 

 7, figs. 2).— This bulletin gives a popular discussion of the characteristics of 

 this pest, the damage done l)y it, and methods of control. 



The potato eelworm, S. B. Doten and P. Frandsen, trans, by Marie Trosi 

 {Nevada Sta. Bui. 76, pp. 7, figs. 2). — An Italian edition of the above. 



On the presence of Tilletia horrida in rice flour, P. Filter (Centbl. Bakt. 

 [etc.'i, 2. AM., 29 (1911), No. 12-lJf, pp. 3-^2-346, figs. ^ ) .—Attention is called to 

 the frequent presence of spores of this smut in rice flour, indicating a more 

 general distribution of this fungus than hitherto supposed. According to the 

 author, T. corona is ouly a synonym of T. horrida. 



A new myxomycete on sugar beets, B. Nem6c (Bcr. Deut. Bot. Gesell., 29 

 (1911), No. 2, pp. 48-50). — The author describes as new a chytridiaceous para- 

 site which is found in the cortical cells of the side roots of the sugar beet. It 

 does not produce hypertrophy of the attacked cells. 



He proposes Sorolpidium betw n. g. and sp. as the name of this organism. 



Root tumors of sugar beet (Jour. Bd. Agr. [London'\, 17 (1911), No. 10, 

 pp. 830, 831, pi. i ) .—Attention is called to the occurrence in England of tumors 

 on the crowns of the sugar beet, a disease which has long been prevalent in 

 many beet-growing regions on the Continent. 



Experiments on the control of Phytophthora on tobacco, H. Jensen (JaarT). 

 Dept. Landb. Nederland. Indie, 1909, pp. 192-197). — The results are given of 

 experiments with lime and ammonium sulphate, nitrate of soda, carbon bi- 

 sulphid, formalin, and potassium permanganate in combating the Phytophthora. 

 It was found that both carbon bisulphid and potassium permanganate appreci- 

 ably checked the Phytophthora without injury to the tobacco plants. 



Injury caused by the apple powdei-y mildew, W. H. Volck (Better Fruit, 5 

 (1911), Nos. S, pp. 39-46, 59-61, figs. 9; 9, pp. 60-69) .—In a general discussion 

 of the characters of this disease, the damage caused by it, and methods used 

 for its control, the author gives the results of a series of experiments with 

 various fungicides in combating this mildew under California conditions. 



The following substances were used as winter sprays in an attempt to kill 

 the fungus on the mildewed twigs : Copper sulphate, Bordeaux mixture, sul- 

 phuric acid, iron sulphate and sulphuric acid, lime-sulphur solution, lime-sul- 

 phur and salt, lye-sulphur solution, potash and soda-lye sulphids and excess of 

 lye, and lime-sulphur solution and copper sulphate. Pruning off infected twigs 

 was also tried as a remedy. Treatments during the growing season, both cura- 

 tive and preventive, were also tried, as follows : Bordeaux mixture, copper 

 sulphate, ammoniacal copper carbonate, copper acetate, copper carbonate, copper 

 benzoate, copper hydroxid, copper sulphid, metallic copper, copper sulphid plus 

 sulphur, iron sulphid, iron sulphid plus sulphur, sulphur (in various forrcs). 

 sulphuric acid, lime-sulphur solution, lime-sulphur solution plus barium car- 

 bonate, potassium sulphid, benzoates (sodium, ammonium, potassium), sali- 

 cylates (same as benzoates), picric acid, phenol, potassium permanganate, 

 zinc oxid, zinc arsenite, kedzie mixture, arsenate of lead, and pruning. 



The wintering-over fungus upon mildewed twigs was so resistant that none 

 of the fungicides killed it, except in the case of the 10 per cent sulphuric acid 



