580 EXPERIMENT STATION RECORD. 



A disease of potato stems in Ohio, due to Rhizoctonia, A. D. Sklby {Abs. 

 in tSdence, ii. ser., 16 {1903), No. 395, p. 138). — For some time past investigations have 

 been in progress at the Ohio Experiment Station upon the Rhizoctonia disease of 

 potatoes. During June of 1902 a well-marked outbreak of this disease was reported 

 at several points within the State. The affected plants show local areas of decay, 

 both above and below the soil line. The most striking feature of the disease is the 

 characteristic rosette aspect of the central leaves of the plants attacked. By the 

 slight incurling of the leaves the affected plants may be readily recognized. This 

 characteristic seems to be quite constant to a number of varieties. 



Observations on the foot disease of wheat, L. Mangin {Jour. Agr. Prat., n. 

 ser., 4 {1902), No. 36, pp. 306-308). — Notes are given on a disease of wheat to which 

 the name "pietin" is given. This disease has been known in France for more than 

 half a century, and has recently been ascribed to attacks of OpMoholus grammis, which 

 is said to occur as a parasite on the wheat plant quite near the ground. Assoi-iated 

 with this fungus are others, of which Leptosphieria herpotrichoidex is the most conniion. 

 The author has conducted a number of experiments to determine the parasitism of 

 these fungi, and both were found to be parasitic, but their role in the development 

 of the disease is quite independent. The Ophiobolus, only in exceptional cases, 

 causes the lodging of the grain, while on the other hand the Leptospha;-ria is quite 

 commonly the cause of the breaking down of the plants. Suggestions are given for 

 the prevention of these diseases, the principal means being the treatment of the seed 

 with fungicides and the selection of resistant varieties, the latter method seeming to 

 offer the most satisfactory results. 



The results of the hot -water treatment of oats and spring wheat for smut 

 prevention, II. Rommetin {Jour. Agr. Prat., n. ser., 4 {1902), No. 39, pp. 407,408). — 

 A brief note is given on the effect of hot water treatment on the eradication of oat 

 smut. In fields which had from 8 to 12 per cent of their spikelets attacked by dis- 

 ease, when this seed was treated with hot water and sown, less than 1:10,000 of the 

 plants were found to be infected. 



A bacterial soft rot of certain cruciferous plants, H. A. Harding and F. C. 

 Stewart {Science, n. ser., 16 {1902), No. 399, pp. 314, 315).— For a number of years 

 the writers have had under observation a soft rot of certain cruciferous plants, par- 

 ticularly of cabbage and cauliflower. During epidemics of black rot, due to Pseudo- 

 monas campeslrh, there is often nmch damage done by soft rot, and at first the dis- 

 ease was supposed to be a virulent form of black rot. Subsequently there were 

 found several attacks of soft rot where there was little or no black rot, and this led 

 to a further study of the cause of the disease. 



From cauliflower beds which were severely attacked the writers isolated an organ- 

 ism which has been secured in pure cultures and inoculated into cabbage and cauli- 

 flower plants, producing the typical form of the disease. Cabbage and cauliflower 

 plants inoculated between March 10 and June 17, with one exception, became rotten 

 at the point of inoculation, while check plants showed no disease or discoloration. 

 The extent of the rotting seems to be dependent upon the condition of the plant. 

 On young, thrifty plants it progresses with great rapidity, while on old, woody, slow 

 growing plants the signs of inoculation do not appear for several days, and in the 

 majority of cases such plants are only checked in growth. 



Cabbage and cauliflower leaves inoculated in the petioles usually become broken 

 down at the point of inoculation within 48 hours. Young plants of kohl-rabi and 

 Brussels sprouts were successfully inoculated in the stem, ruta-bagas in the leaf peti- 

 oles, and radish and flat turnip by inoculation in the fleshy roots. The organism 

 was tested on a large number of different kinds of plants, and from present intlica- 

 tions it is believed that it is one of a group of organisms closely related to Bacillus 

 carotovorus, which has been described as occurring on carrot and other plants (E. S. R., 

 13, p. 362). 



