108 PATHOLOGY [BoT. Absts., Vol. X, 



spots in the rings adjoining the bark. In some cases they are found in the last 2 or 3 rings and 

 it is supposed that the 1st infections must have taken place as early as 1917. The coloring 

 matter from these spots seems to pass into the other portions of the rings so that all of the 

 rings having dark spots are somewhat darker. The same symptoms are to be seen also in the 

 lower portion of the stem and even in the roots. Cultures from discolored portions of the wood 

 have yielded a number of fungi; the work on etiology is to be continued. — D. Atanasoff. 



697. Stevens, F. L. Helminthosporium and wheat foot-rot. [Abstract.] Phytopath- 

 ology 11: 37. 1921. 



698. TisDALE, W. H., AND J. MiTCHELL Jenkins. Rlcc Straight head and its control. 



[Abstract.] Phytopathology 11: 42-43. 1921. 



699. Uphof, J. C. Th. Eine neue Krankheit von Cephalanthus occidentalis L. [A new 

 disease of C. occidentalis L.] Zeitschr. Pflanzenkrankh. 31: 100-108. 1 fig. 1921. — The 

 author describes a disease of Cephalanthus occidentalis from southeastern Missouri, U. S. A., 

 which is believed to be a mosaic disease. Of 24 inoculations with juice from an affected plant 

 18 proved successful. Leaves, petioles, shoots, and roots may show effects of the attack. It 

 is suspected that the disease is carried in the soil, the "virus" from infected roots being spread 

 through the soil, principally by flooding. — H. T. Gtissow. 



700. Valleau, W. D. Wildfire and angular leaf-spot of tobacco. Kentucky Agric. Ext. 

 Circ. 89. 16 p., illus. 1921. — The author reports the severe outbreak of wildfire (Bacterium 

 tahacum, and angular leaf-spot {Bacterium angulatum) of tobacco in Kentucky in 1920. A 

 description of the diseases is given with the results of inoculation experiments in which it was 

 shown that infection takes place primarily through the under side of the leaf. Preventive 

 measures are discussed. Bagging seed heads is suggested as a means of control through pre- 

 venting seed-pod infection; selection of seed from apparently disease-free fields is not consid- 

 ered a sure means of securing disease-free seed as numerous seed beds were affected in 1920 

 though the diseases were not present in 1919 to a noticeable degree. — W. D. Valleau. 



701. Walker, J. C. The occurrence of dodder on onions. [Abstract.] Phytopathology 

 11: 53. 1921. 



ERADICATION AND CONTROL MEASURES 



702. Beach, F. H. Results of apple blotch control in southern Ohio. Trans. Indiana 

 Hort. Soc. 1919: 63-72. 4 fig- 1920. — The importance and distribution of blotch (Phyllosticta 

 solitaria) in Ohio is given. The unsatisfactory control secured by a Bordeaux spray at in- 

 tervals of 3, 6, and 9 weeks after petal fall in 1918 led to the trial of a 2-, 4-, 6-, and 10-week 

 (after petal fall) program in 3 orchards in 1919. A 3-5-50 Bordeaux was used on the varieties 

 Ben Davis an d^ Smith Cider. Data are presented which show that an excellent control of 

 blotch was obtained. It is concluded that the 2-, 4-, and 6-weeK schedule is far superior to 

 the 3-, 6-, and 9-week schedule. The importance of the earlier application of the 1st spray is 

 emphasized. In a 4th orchard, the relative [importance of the 2- and 4-week applications was 

 demonstrated. An account is given of the method of handling the spray gun in order to secure 

 thorough coating of the fruit, foliage, and twigs. It was found that the upper side of the fruit 

 in the top of a tree was commonly left unprotected. Recommendations for blotch control 

 include, in addition to the spray program, dormant pruning to open up dense portions of the 

 tree and to eliminate dead and cankered wood, and spring application of nitrate of soda 

 fertilizers. — Max W. Gardner. 



703. Bernatsky, J. Perozid sowie Kupfervitriol gegen Oidium. [Perozid and copper 

 sulphate versus Oidium.] Zeitschr. Pflanzenkrankh. 31: 94-96. 1921. — The author reports 

 excellent results from the use of "perozid" against Oidium of pumpkins. He emphasizes 

 that his experiments have no reference to the dreaded Plasmopara cubensis, only to Oidium. 

 He employed sulphur dust, 1 per cent copper sulphate, and "perozid" (2 per cent) 3 times 



