52 EXPERIMENT STATION EECORD. 



Frost is thouglit to influence tlie sprouting of the grain, but just how has not 

 yet been determined, and this is true also of the chemical changes in chilled 

 plants. Resistance to cold by some varieties seems to show a relation to the 

 water content, and it also appears to be true that an increase of water content 

 renders the plant more sensitive to outside influences. Nocturnal frosts seem to 

 render the stems liable to breaking, and chilling affects the heads also in ways 

 not fully understood. 



Studies of club root. — II, Disease resistance of crucifers; methods of com- 

 bating club root, G. C. Cunningham {Vermont Sta. Bui. 185 {19U), pp. 67-96, 

 pis, 8),— This bulletin is the second on club root studies (E. S. R., 31, p. 642); 



In the present publication the author gives the results of observations on 

 the susceptibility of different cruciferous plants to club root, and it was found 

 that the great majority, if not all crucifers, were more or less susceptible. 

 Cabbages showed variety resistance, a number of varieties being somewhat less 

 subject to attack than others 



Radishes showed a wide range of susceptibility, and in case of turnips and 

 rutabagas the rate was even greater than in cabbages or radishes. In this 

 wide range of susceptibility the author believes that satisfactory means of 

 combating the disease may be found. 



An examination of many thousands of plants, including 28 genera and 104 

 species, led the author to describe 6 types of hypertrophy which are more or 

 less characteristic of certain cracifers. 



For the control of the disease the application of lime, preferably air-slaked 

 lime, at the rate of 150 bu. to the acre, greatly increased the production of 

 marketable cabbage. The lime to be effective should be thoroughly worked 

 into the soil to a depth from 6 to 9 in. In 1912 experiments showed that hilling 

 up about cabbage stalks caused the formation of adventitious roots and ma- 

 terially increased the crop, but in 1913 no beneficial results were obtained, 

 possibly on account of the dry season. 



A bibliography is given. 



Studies on potato anatomy, von Tiesenhatjsen {Jahresher. Kaiser Wil- 

 Jielms Inst. Landw. Brotnberg, 1913, pp. 23-25). — A brief discussion is given of 

 studies in progress, the results of which thus far as related to phloem necrosis 

 in the potato are said not to be in complete agreement with the conclusions 

 announced by Quanjer (E. S. R., 29, p. 347). 



Diseases of potatoes, II, III, H. L. Rees {Washington Sta., West. Wash. 

 Sta. Mo. Bui, 1 {1014), Nos. 6, jvp. 9-16, figs. 1; 7, pp. U-1 6 ) .—F ovular descrip- 

 tions are given of Rhizoctonia or little potato disease, potato wilt or dry rot, 

 blackleg, silver scurf, scab, powdery scab, internal brown spot, and internal 

 cracking of the potato, with suggestions for their control. 



The spindling-sprout disease of potatoes, F. C. Stewart and F. A. Sirrine 

 {New Yorlc State Sta. Bui. 399 {1915), pp. 133-143, pis. 3; ahs. in Phytopathol- 

 ogy, 4 {1914), No. 6, p. 395). — ^Attention is called to the fact that Long Island 

 potato growers in 1914 who planted their fields with home-grown seed secured 

 a poor stand, many of the plants being small and weak. The seed pieces did 

 not rot prematurely and there was no spotting, rolling, or curling of the leaves, 

 or other pathological symptom. The tubers used for seed purposes were small, 

 but otherwise normal in appearance. 



Examination of unsatisfactory stands showed that weak plants and missing 

 hills were in most cases due to using, for seeds, tubers which produced slender 

 thread-like sprouts. This trouble is considered due to a weakened or debili- 

 tated condition of the seed tubers and is thought to be a result produced by the 

 excessively hot weather in the summer of 1913. 



