150. EXPERIMENT STATION RECORD. 



gators as lo tlic ciiusc of lliis tlisc-isi' .•iiid tlic identity of the fungus, ;ind de- 

 cides that from the evidence at hand it sliould l)e called »S'. fiubterranea. 



Experiments have been carried on in pot cultures to test the possibility of 

 preventing this disease. Treating scabby tubers with a 2 per cent sohition of 

 Bordeaux mixture gave a crop free from scab, but the use of sulphur was with- 

 out any benefit. Covering uncut tubi rs with spores of the fungus did not 

 affect the resulting crop. As a result of his experiments, the author recom- 

 mends the planting of whole tubers previously treated with fungicides. 



Leaf curl or bacterial ring disease of potatoes, J. Branol ( Wiener Landio. 

 Ztg., 59 (1909), Nos. 10, pp. 69t-(!93, figs. /,; 7/, pp. 101, 702, figs. 5).— A 

 popular description is given of the leaf curl or bacterial ring disease of potatoes, 

 which it is said has become widely distributed throughout Germany, Denmark, 

 Holland, and Switzerland, and lately has become quite troublesome in a num- 

 ber of portions of Austria and Hungary. 



The ring disease of potatoes, L. C. Coleman (Dcpt. Agr. Mysore, Mycol. Ser. 

 Bui. 1, pp. 15, pis. U/). — This is a preliminary popular report on the bacterial 

 disease of potatoes known as the ring disease, and is to be followed by a more 

 technical paper giving the results of the author's investigations. 



A new rust of orchids in greenhouses, E. Griffon and A. Maublanc (Bui. 

 Trimcst. Soc. Mycol. France, 25 (1909), No. 3, pp. 135-139, pi. 1).—X descrip- 

 tion is given of Hemileia oncidii n. sp., a fungus causing considerable injury to 

 species of Oncidium growing in greenhouses. 



Orchard fungus diseases, F. M. Rolfs (Ann. lipt. Mo. Bil. Hort., 2 (190S), 

 pp. 63-70). — Descriptions ai'e given of a number of the more common fungus 

 diseases of peach trees, with suggestions for their control. For most of the 

 diseases the author has found self-boiled lime-sulphur mixture, if properly 

 prepared and applied, to be very satisfactory. 



A disease of neglected peach trees, F. M. Holfs (Ann. Rpt. Mo. Bd. Hort., 

 2 (1908), pp. 278-283). — Attention is called to a disease of peach trees due to 

 the fungus Cytospora, which has previously been described as occurring in 

 New York (E. S. R., 13, p. 148). 



Experiments conducted at the Missouri Fruit Station showed that the Cy- 

 tospora is the imperfect form of Valsa leucostoma, and that the organism is 

 capable of attacking the limbs, twigs, and trunks of peach, plum, apricot, and 

 cultivated and wild cherry trees. It has also been observed on apple and 

 pear trees and rose and rasjjberry canes. On the peach tree infections are 

 said to take place invariably at the buds. If the weather conditions are favor- 

 able for its growth, the fungus becomes active during the late winter and early 

 spring months, and periods of warm weather followed by late frost appear to 

 render the tissues extremely favorable to its development. 



During 1907 observations were made on the rate of advancement of the 

 fungus, and the advancement on the twigs was found to average about 8 in. 

 between February and October. Inoculations on healthy twigs of pure cultures 

 of the fungus produced the characteristic winterkilled appearance. The fungus 

 seems to start the wounds and plays a prominent part in extending the injury, 

 but after it once gets established other organisms materially aid in destroying 

 the trees. 



Applications of Bordeaux mixture and lime-sulphur wash materially reduced 

 the twig infections but did not check the enlargement of the cankers or sun- 

 scald areas produced by the fungus, and consequently these fungicides can not 

 be relied upon as means of controlling the disease after the organism has once 

 become established. 



[Some peach diseases], M. A. Blake and A. J. Farley (Neio Jersey Stas. Rpt. 

 1908, pp. 53-56, pis. 3). — Descriptions are given of peach leaf curl and peach 



