202 PATHOLOGY [BoT. Absts., Vol. VIII, 



1396. Howard, W. L., and W. T. Horne. Brown rot of apricots. Univ. California 

 Agric. Exp. Sta. Bull. 326. 73-88. 1920. — The results for one season, using 16 different spray 

 treatments, justify the conclusion that apricot blossoms may be effectively protected from 

 brown rot by spraying the trees once, shortly before they come into bloom, with either lime- 

 sulphur or Bordeaux mixture. The lime-sulphur should be used at the rate of 1 gallon to 9 

 gallons of water, and the Bordeaux mixture at a strength of 4-5-50 (4 lbs. bluestone, 5 lbs. 

 fresh stone lime, 50 gal. water). The so-called dry lim-e-sulphur, used at the rate of 12 lbs. 

 to 50 gal. of water, is quite as effective as either of the other 2 sprays. Early winter spraying 

 against the brown rot is useless. Brown rot on the fruit cannot be prevented by cutting out 

 the diseased twigs, but twig blight can be controlled as effectively, and more easily, by remov- 

 ing them in the fall or winter as by cutting them out in the spring. — A. R. C. Haas. 



1397. Hubert, E. E. Observations on Cytospora chrysosperma in the Northwest. Phy- 

 topath. 10: 442-447. 1920.— The unusually dry siunmers of 1917, 1918, and 1919 favored the 

 development of Cytospora chrysosperma on shade and ornamental trees. It is common and 

 injurious in Montana, Idaho, Wyoming, and Washington on species of Populus, Acer and 

 Salix, Prunus demissa, Sorbus scopulijia, and Sambucus glauca. The author produced in- 

 fection on small plants of Populus trichocarpa low in vigor. Control methods consist in 

 selecting resistant species, giving proper care to shade trees, and closely inspecting nursery 

 stock. — C. J. Humphrey. 



1398. Johnson, James. Fusarium-wilt of tobacco. Jour. Agric. Res. 20:515-535. PI. 

 63-67. 1921. — This previously undescribed disease was found to occur in Maryland, Ohio, 

 and Kentucky. It is characterized by a yellowing and wilting of the leaves, usually fol- 

 lowed by death of the entire plant. The vascular system of infected plants is characteristi- 

 cally brown or black. The pathogene concerned is Fusarium oxysporum (Schlecht.) Wr. var. 

 nicotianae n. var., of which a description is given. The fungus differs somewhat from F. 

 oxysporum (Schlecht.) Wr. in morphology, physiology, and pathogenicity. Infection was 

 secured with 2 strains of F. oxysporum from potato on tobacco, but not with the tobacco strain 

 on potato. The symptoms of the wilt produced by the potato strain were not identical with 

 those produced by the strain from tobacco. Conditions favoring infection with the tobacco- 

 wilt organism are heavy soil infestation, wounded host tissue, a relatively high soil tempera- 

 ture (2S-31°C.), and a susceptible variety. Varieties of tobacco differ markedly in their 

 resistance to the disease. The White-Burley variety is most susceptible, and the Havana 

 Seed and Cuban varieties are among the most resistant. The development of resistant strains 

 within the various susceptible varieties offers the most helpful means of control. Growers 

 are advised not to grow tobacco on infested soils and to avoid the danger of infested seed 

 beds. — L. M. Massey. 



1399. Matz, Julius. Gumming disease of sugar cane in Porto Rico. Phytopath. 10: 

 429-430. / fig. 1920. — The author gives the distribution of the gumming disease caused by 

 Bacterium vascularum. The variety "Otaheite" is very susceptible to the disease. "Caven- 

 gerie," a less popular variety, is apparently very resistant. — William B. Tisdale. 



1400. Matz, Julius. Gumming of sugar cane in Porto Rico. Sugar 22: 282-283, 1920.— 

 A description and history of the gumming disease of sugar cane caused by Bacterium vascu- 

 larum. — C. W. Edgerton. 



1401. Matz, Julius. La gomosis de la cana de azucar. [Gumming of sugar cane.] Sugar 

 22 : 363-364. 1 fig. 1920. — A translation in Spanish of an earlier publication [see preceding 

 entry]. — C. W. Edgerton. 



1402. Merker, Gustav. Ein neuer Pilzschadling im Fichtenpfianzgarten. [A new fungus 

 pest in Norway spruce (Picea excelsa) nurseries,] Naturw. Zeitschr. Forst- u. Landw. 18: 

 218-219. 1920, — This new disease was discovered on 4-year spruce in the spring of 1920 in 

 the "Forstverwaltung" Gratz, near Troppau in Silesia, and the causal organism was identi- 



