March, 1920] PATHOLOGY 115 



780. McHatton, T. II., and J. W. Fikor. Spray calender for Georgia. Georgia State 

 Coll. Agric. Bull. 170. 12 p., S fig. 1919. 



781. Osborn, T. G. B. Report of the Consulting Botanist and Plant Pathologist. Kept. 



Min. Agric. South Australia 1917-18: . 191S. [Issued separately, 3 p.]— "Take-all" 



(Ophiobolus graminis) on oats is reported, but the disease is not so severe as on wheat and 

 barley. — A species of Alternaria was apparently responsible for barren wheat plants. — Leaf 

 stripe, HelmirUhosporium inconspicuum, on Zea mays is reported for the first time. — The 

 following potato diseases were found: early blight (Alternaria solani), wilt (Fusarium solani), 

 Irish blight (P. infestans), scab (Rhizoctonia solani); the latter disease is responsible for 

 reduction in yield and a depreciation of the crop. — A dieback of apricots is attributed to 

 senility. — Coniothecium chromatosporium is constantly associated with a canker of apple and 

 pear. — Venturia pomi, of apples and pears, causes blossom rot of certain sheltered apple 

 trees. — A bacterial disease of Citrus is being studied. — The following diseases have been 

 found: onion mildew (P. schleideniana) , cucurbit mildew (Erysiphe cichoracearum) , streak of 

 sweet pea (Bacillus lalhyri), anthracnose of Platanus (Gloeosporium nervisequum) , also found 

 injuring American oaks (Quercus sp.), rhododendron leaf disease (Gloeosporium rhododendri), 

 poplar leaf blister (Taphrina aurea), smut of couch grass (Cynodon dactylon) caused by 

 I'stilago cynodontis. — D. Reddick. 



782. Palm, B. J. Sur une Plasmodiophoracee nouvelle, Liginera isoetis. [A new slime- 

 mold.] Svensk Bot. Tidsskrift 12: 228-232. 3 fig. 1918.— See Bot. Absts. 3, Entry 729. 



783. Parrott, P. J., H. E. Hodgkiss, and F. Z. Hartzell. The rosy aphis in 

 relation to abnormal apple structures. New York Agric. Exp. Sta. [Geneva] Tech. Bull. 66. 

 29 p., 8 pi. (2 colored), 6 fig. 1919. — Apples attacked by rosy aphis (Aphis sorbi Kalt.) are 

 abnormally small, poorly colored and unsymmetrical. They contain fewer seeds than normal 

 apples, the seeds are of smaller average size, and more of them are imperfect. Also, the seeds 

 are more variable in number and weight. Although attacks by rosy aphis increase the number 

 of small, few-seeded and seedless fruits, the number of such fruits which fall prematurely is 

 fewer than under normal conditions. Different structures of the apple are affected in dif- 

 ferent degrees, the weight of the fruit being most affected, weight of seeds next, and number 

 of seeds least. Both in aphis-injured apples and normal apples the relation between fruit 

 weight and seed weight appears to be closer in small fruits than in large ones; but this relation 

 is not very marked in any case. While there is no reduction in the number of primary fibro- 

 vascular bundles, even in severely malformed fruits, their development is arrested on the 

 side of greatest distortion, and the number of ultimate branches is much fewer than in normal 

 fruits. — F. C. Stewart. 



784. Pollock, J. B. The longevity in the soil of the Sclerotinia causing brown rot of 

 stone fruits. Rept. Michigan Acad. Sci. 20: 279-280. 1918. — Evidence is set forth to show 

 that the sclerotia of the Sclerotinia causing plum brown rot may remain alive in fallen mum- 

 mied fruits for 10 years at least, and some of them produce apothecia every year. It is sug- 

 gested that this longevity of the fungus renders control by disposal of mummied fruits more 

 difficult. — L. R. Hesler. 



785. Reed, George M. Phytopathological survey of the trees and shrubs of Prospect 

 Park and the Botanic Garden (Brooklyn). II. Report of the second season's work. Brooklyn 

 Bot. Gard. Rec. 7: 14-23. Jan., 1918.— Continuation of: Same title. I. Report of the first 

 season's work (Ibid. 6: 14-20. Jan., 1917). — The area intensively surveyed contained 

 approximately 1830 trees, representing about 50 different kinds. 231 trees had decayed areas 

 classified as major, and 192 trees had decayed areas classified as minor. Thus 423 trees, or a 

 total of 23 per cent were found to be injured by decay producing fungi. Certain kinds of 

 trees, as the silver maple, Norway maple, the ashes, and the birches, showed a very high 

 percentage (25 to 50 per cent) of decayed areas. Other species showed lower percentages of 

 injury. — C. S. Gager. 



