650 EXPERIMENT STATION RECORD. 



The leaf cast diseases of currants and their successful control, H. Rosen- 

 TiiAT, (Dent. OhHthau Ztff., 1910, No. U,, pp. 172, 173, fig. i).— It is claimed that 

 the two fungi GloEosporium curratmn and G. riMs, which often cause the com- 

 plete defoliation of currant bushes, can be successfully controlled by a i per 

 cent soda Bordeaux mixture applied about 8 days after blossoming, with 

 a second application when the berries are gathered. 



Cauliflower disease of strawberries (Jour. Bd. Agr. [I^ondon], 17 (1910), 

 No. 3, p. 21Ji, fig. 1). — In this disease, due to the attacks of a nematode {ApTie- 

 lenchus fragarke). the flower buds and flower stems are stunted and form short, 

 fleshy, irregular masses resembling pieces of cauliflower. The buds in tbe axils 

 of the leaves become hard and scaly and do not grow out into stolons. The 

 nematodes are present in the diseased flower buds and the swollen portions of 

 the plant. 



Diseased plants should be removed and burned. Sulphate of potash has 

 proved effective in checking the disease when applied at the rate of 100 lbs. 

 per acre. 



The diseases of the grape and means of combating them, V. Xazari ( Sta::;. 

 Hpcr. Agr. ItaL, //2 (1909), Xo. 9, pp. 609-S06). — In this paper are described 

 the insect and fungus enemies of the grape as they have appeared each succes- 

 sive year from 1S9S to 1907, inclusive, together with the means used for their 

 control. An extended bibliography on the disease of the grape for each year is 

 appended. 



Field studies of the crown gall of the grape, G. G. Hedgcock ( U. S. Dcpt. 

 Agr., Bur. Plant Indus. Bui. 183, pp. .'lO, pis. //). — The results are reported of 

 several years' investigations of the crown gall of the gi'ape in the western part 

 of the United States, and esi^ecially of the susceptibility and immunity to the 

 disease of the most important varieties of grajjes. The author also discusses 

 the distribution and importance of crown gnll, its two forms (root and cane 

 galls), its development, effects, cause, cure, and prevention, and gives an exten- 

 sive bibliography of the subject. 



In the experiments on the susceptibility and resistance of various species and 

 varieties of grapes to this disease it was found that two factors enter into the 

 problem. One of these is the susceptibility of the species or varieties to frosts 

 and similar injuries in the locality where they are grown; for example, the 

 Concord, Catawba, Delaware, and other American varieties are perfectly hardy 

 and usually free from the disease, when varieties of Vitis vinifcra are seriously 

 injured by freezing and frosts and become badly diseased. The second is the 

 variation in the chemical constituents of the sap, the sap of the most resistant 

 vines being especially acid to the taste. Vines of V. cordifolia and F,. llnsecomU 

 are susceptible, while varieties of V. rupestris and V. vulpina are quite resistant, 

 for example, Rupestris St. George and Rupestris Martin. Of European varieties, 

 the Mission of California, Muscat of Alexandria, Flame Tokay, Rose of Peru, 

 and Malaga are very susceptible, but may be grown in infected areas on resist- 

 ant stocks. 



The cause of the disease seems to be Bacterium tiimrfacicns, which produces 

 similar galls on a variety of plants. The crown gall is a communicable disease, 

 and usually attacks the vine through wounds from frost, itrunlng. Insects, etc. 

 Its prevention is mainly a matter of growing resistant varieties or grafting non- 

 resistant scions on resistant stocks. All diseased vines, should be dug up and 

 burned as soon as discovered. In the arid regions, planting deeply, so that not 

 more than one bud will remain above ground is recommended as a protection 

 from freezing and the burning sun. Fungicides gave negative results. 



The acidity of the sap of plants in relation to their resistance to the 

 attacks of parasites, R. Averna-Sacca (.4"". A'. .s'^/~. VJiiiii. Agr, Spvr. Roma, 



