Junk, 1920J PATHOLOGY 383 



not the only physiological symptom of the disease. Presumably the rolling of the leaves 

 occurs as a o tnsequence of the disturbed metabolism present infernally. Be doubts, how- 

 ever, whether anatomical abnormalities such as Quanjcr's phloem necrosis may be regarded 

 as causal to the reduced translocation of starch. — //. T. GUssow. 



2631. Eustace, H. J. Horticultural notes. Michigan Agric. Exp. Sta. Quart. Bull. 1: 

 133. Feb., 1919— See Bot. Absts. 3, Entry 2331. 



2632. Eustace, H. J., and R. H. Pettit. Spray and practice outline for fruit growers. 

 Michigan Agric. Exp. Sta. Special Bull. 93. S2 p., 6 fig. 1919.— See Bot. Absts. 3, Entry 

 2332. 



2633. Eyre, J. Vargas, E. S. Salmon, and L. K. Wormald. Further notes on the pow- 

 dery mildews and the ammonium polysulphide wash. Jour. Bd. Agric. Great Britain 25: 

 1191-1497. 1919. — During the stage from the germination of the spore through the actual 

 penetration of the leaf tissue and to the formation of the mycelium on the surface of the 

 leaf, the hop mildew (Sphaerotheca hamuli) "offers the maximum resistance to the fungicide, 

 requiring not less than double the strength which is lethal in the later stage." Two appli- 

 cations of ammonium polysulphide solution at the strength of 1 gallon stock solution to 99 

 gallons water containing 5 pounds soft soap are required to control the disease. The method 

 of preparation of the stock solution, which is not of a kind that the growers can make for 

 themselves, is given.— The ammonium polysulphide and soft soap wash has proved effective 

 in controlling American gooseberry mildew and consequently may be used in place of lime- 

 sulphur when this material interferes with the marketing of the berries.— M. B. McKay. 



2634. Farrell J. Apple culture in Victoria. Jour. Dept. Agric. Victoria 17:287-295. 

 PI. 14- 1919.— Continuation of an earlier article. [See Bot. Absts. 3, Entry 758.] This 

 section deals with the fungous diseases of apples and their control. — J. J. Skinner. 



2635. Fawcett, H. S. Psorosis (scaly bark) of orange trees in California. California 

 Citrograph 4: 107, 133, 134. 5 fig. 1919.— This serious orange disease in California manifests 

 itself by an outer layer of bark in certain patches being broken into small irregular pieces 

 and by these being pushed off. Several years usually elapse before the death of the infected 

 limb. The causal organism, if such there is, has not been determined. The progress of the 

 disease is arbitrarily divided into three stages which are described. Suggestions for treat- 

 ment: first stage, aseptic excission; second stage, light scraping with application of bordeaux 

 paste; third stage, small chance for cure, if on limb, remove; if on trunk, gouge out dead or 

 affected wood, disinfect and paint with benzene-asphalt paint. — /. E. Coit. 



2636. Fawcett, George L. [Rev. of : Dracopoulos, Juan N. La gomosis de los citrus. 

 (Citrus gummosis.) Corrientes, 1918.] Rev. Indus, y Agric. Tucuman 8: 153-155. 1918. 



2637. Fawcett, H. S. Citrus blast. California Citrograph 5: 3. S fig. 1919.— A bac- 

 terial disease, due to Bacterium citrarefaciens, at present confined to northern California. 

 Active only in winter and early spring. The organism destroys leaves, kills back many of 

 the fruiting twigs and results in the formation of reddish brown scabs on the live twigs and 

 shoots usually at and surrounding the base of each dead leaf petiole. The organism does 

 not attack the fruit after it is set. Different varieties are differently affected, the navel 

 orange being most injured and lemons but slightly affected. There appears to be a relation- 

 ship between the following conditions and the severity of the disease: — direction of the pre- 

 vailing wind, distribution of rainfall, weakness of tree from neglect, age of tree, and time 

 of maturity of leaves and branches of the year before. A bibliography is appended. — 

 /. E. Coit. 



2638. Federal Horticultural Board, U. S. Dept. Agric. Quarantine on account of 

 flag smut and take-all diseases. Notice of quarantine No. 39 (with regulations). Serv. and 

 Reg. Announce. 64: 77-79. 1919. — Also issued as an unnumbered pamphlet from the office 



BOTANICAL ABSTRACTS, VOL. Ill, NO. 6 



