650 EXPERIMENT STATION RECOED. 



India due to Colletotrichum falcatum and held to be identical with the form 

 attacking the leaves and stalk as noted in Louisiana by Edgerton (E. S. R.. 

 26, p. 548). 



It is stated that spread of infection from growing canes is rather unlikely 

 in the absence of insect parasites', but that from dead and rotting canes the 

 fungus may be carried to sound ones by soil or irrigation water, by the feet 

 of workmen, or by the cane fly (Fyrilla aherrans). The fungus is said to enter 

 the plant most readily at the eye, but leaves, stems, and shoots may be attacked, 

 producing typical symptoms. Wounds also favor its entrance. Much of the 

 damage by this fungus is due to inversion of cane sugar owing to the presence of 

 invertase, which has been demonstrated both in the fungus and in the nutritive 

 medium. 



The disease is said to be less severe on the lighter canes. Care in selection 

 to secure only sound cane, removal of plants showing infection, and long period 

 rotation are preventive measures suggested. 



Some new sug-ar cane diseases, E. J. Butler and A. Hafiz (Mem. Dept. Agr. 

 India, Bot. Ser., 6 (19 J 8), No. 6, pp. 181-208, pis. 6, fig. i).— Continuing the 

 above report on sugar cane diseases the authors describe three fungi. One 

 associated with a cane wilt is named CeplialospoHum sacchari n. sp. A second 

 found in a collar rot is named Ilendersonina sacchari n. g. and sp. A third, 

 said to cause a leaf spot or streak, is named Helminthosporium sacchari n. sp. 

 These are not known to cause much loss at present, but further investigations 

 are in progress. 



The importance of the tarnished plant bug- in the dissemination of fire 

 blight in nursery stock, V. B. Stewart iPJiytopathoJogij, 3 (1913), No. 6, pp. 

 273-276, pi. i).— In a previous piiblication (E. S. R.. 29. p. 348) the author 

 called attention to the role of various insects in the dissemination of fire blight 

 in nursery stock. The investigations previously described have been continued, 

 and some experiments are reported on the tarnished plant bug {Lygus praten- 

 sis), which appears to be the most important insect in transmitting the blight 

 to healthy trees. 



In these experiments tarnished plant bugs were transferred from infected 

 trees or were placed in contact with cultures of the organism and then trans- 

 ferred to sound trees. The results of the experiments make it evident that the 

 tarnished plant bug is able to transmit the casual organism of fire blight from 

 exuding blight lesions to healthy shoots. 



Apple leaf spot {Bd. Agr. and Fisheries [Londoni, Leaflet 281 {1913), pp. 4, 

 figs. Jf)- — A brief description is given of 8ph(rropsis malorum attacking the 

 trunk, branches, leaves, and fruit of apple, pear, and quince in the United 

 States and more recently in England. 



Removal of dead branches and leaves, and spraying with half strength Bor- 

 deaux mixture about a week after the fall of the petals and again about a month 

 later are recommended, as is also treatment with lime-sulphur wash. 



Control of apple black rot, F. A. Wolf {Phytopathology, 3 {1913), No. 6, pp. 

 288, 289). — The apple black rot, due to Sphwropsis malorum, is said to be 

 becoming very destructive in certain commercial apple orchards in Alabama, and 

 some experiments were carried on in 1912 and 1913 for its control. 



In 1912 the trees were sprayed with lime sulphur, but it proved entirely in- 

 effective against either the black rot or the bitter rot, irrespective of the time 

 and number of applications. In 1913 the experiment was repeated, Bordeaux 

 mixture being used as the fungicide. The first application was made about the 

 middle of July and a second about two weeks later. Satisfactory results were 

 obtained from this work, less than 1 per cent of the variety Champion being 

 affected while from 85 to 90 per cent control was obtained with Black Ben Davis. 



