1918] DISEASES OF PLANTS. 251 



wilt of tobacco has been observed in 11 counties of North Corolina and the 

 tomato wilt caused by the same organism in 39 counties of the State. Cultural 

 studies on the identity of the organism from A^arious host plants showed that 

 there was no greater variation in the strains from the different hosts than in 

 strains all of which came from the same host. 



As a result of cultural studies, the authors have added 13 species of plants to 

 the known hosts of B. soJanaceartim, and it is claimed that 9 families are now 

 known to be subject to attack. Attention is called to the economic bearing 

 of weed and cultivated host plants in problems of control. 



Buckeye rot of tomato fruit, C. D. Shekbakoff {Phytopathology, 7 (1911), 

 No. 2, pp. 119-129, figs. 5). — A detailed account is given of a rot of tomato 

 fruit in Florida locally known as buckeye rot. of which a preliminary report 

 has been noted (E. S. R., 37, p. 601). The rot is said to be caused by Phytoph- 

 thora terrcstria n. sp., a technical description of which is given. 



This disease occurs only on fruit that touches or nearly touches the ground, 

 but may cause considerable injury to fruit in the field and in transit. Staking 

 the plants in the field to remove the fruit as far as possible from the ground 

 and holding the fruit for a few days before packing are methods of control 

 suggested. 



Phytophthora infestans, causing' damping'-off of tomatoes, J. E. Howitt 

 {Phytopathology, 1 {1911), No. 4, p. 319). — Attention is called to the damping- 

 off of tomatoes due to P. infestans, at least 50 per cent of the plants from large 

 nursery shipments to certain sections of Ontario having been destroyed in 1916. 



Apple scab on the twig's, M. T. Cook and G. A. Schwabze {Phytopathology, 

 1 {1911), No. 3, pp. 221, 222). — The authors report the occurrence on apple twigs 

 of Venturia ponii in the spring of 1916, viable conidia having been present in 

 considerable abundance. The presence of the organism on the twigs is believed 

 to have an important bearing on the infection of apples during the growing 

 seas(jn. 



Blister spot of apples and its relation to a disease of apple bark, D. H, 

 Rose {Phytopathology, 1 {1911), No. 3, pp. 198-208, figs. 3).— A disease of apple 

 is described in which small blister-like spots are formed in the fruit of a num- 

 ber of varieties. The trouble is said to be due to I'scudomona.s papulans n. sp. 



As a result of inoculation experiments, the author has shown that this species 

 of bacteria can also produce two forms of disease on the twigs and branches 

 known as rough bark or scurfy bark canker. A preliminary comparative study 

 of the culture characteristics of the organisms taken from the fruit and the 

 bark suggests that the differences between them are of degree rather than of 

 kind and that all three diseases are probably caused by one species of organism. 



Apple diseases in Indiana, with spray schedule, H. S. Jackson (Indiana 

 ^ta. Circ. 10 (1911), pp. 23, figs. IJf). — A popular description is given of a num- 

 ber of the more common diseases to Avhich the apple is subject, and a spray 

 schedule is appended for the prevention of fungus and insect attacks. 



A new leaf spot disease of cherries, B. A. Rudolph (Phytopathology, 7 

 (1911), No. 3, pp. 188-191, figs. 3). — A leaf spot of sweet cherries first obsprved 

 by the author in 1913 has been investigated at some length and determined to 

 be due to a fungus of close relationship to Alternaria citri, which is technically 

 described as A. citri cerasi n. var. 



Conspicuous spots are formed upon the leaves of cherry, the fungus usually 

 gaining entrance to the leaf tissue through injuries made by insects. Inocula- 

 tions on the bark and wood of normal cherry twigs gave negative results, but 

 from inoculations upon cherry leaves characteristic spots were obtained, as 

 also from inoculations on the leaves of a considerable number of other plants, 

 embracing apple, box elder, prune, plum, avocado, watermelon, and peach. 



