244 EXPERIMENT STATION EECOED. 



Of preventive and remedial measures, drainage and rotation are regarded as 

 practicable, and cultivation of resistant varieties as desirable, if found to be 

 possible. 



The action of sulphuric acid on stalk disease of wheat, J. Capus (Coinpt. 

 Rend. Acad. Agr. France, 1 {1915), Ko. 6, pp. 224-231) .—The results are given 

 of a study on tlie development of foot or stalk disease of cereals ascribed to 

 Leptosjihceria herpotrichoides. 



The action of sulphuric acid, regarding which conflicting opinions are held, 

 has been studied. It is thought that the killing of the lower leaves by the use 

 of this acid, as reported by Rabate (E. S. R., 30, p. 441), may be the actual 

 cause of the checking of the fungus, which is opposed by aeration and sunshine, 

 and also by di-yness of the soil, luxuriant growth or abundant soil moisture 

 being very favorable to its development. 



Infection experiments with timothy rust, E. C. Stakman and Louise Jen- 

 sen {U. S. Dept. Agr., Jour. Agr. Research, 5 (1915), No. 5, pp. 211-216) .—As 

 a result of experiments carried on at the Minnesota Station, in which inocula- 

 tions were made on seedlings, the authors have found that timothy rust (which 

 has been called Puccinia phleipratensis) may be supcessfully transferred di- 

 rectly from timothy to Avcna sativa, A. fatua, A. elatior, Hordeum vulgare, 

 Secale cercale, Dactylis gJomerata, Elymus virginicus, LoJiuin italicum, L. 

 perenne, and Bromns tecionim. 



Attempts to increase the infection capabilities of the rust by the use of bridg- 

 ing hosts for short periods of time were unsuccessful. The infection capabili- 

 ties of timothy rust are said to be quite similar to those of P. graminis aveno'. 

 Attempts to infect timothy with P. graminis avcnxe and P. graminis hnrdei were 

 unsuccessful. The morphology of the spores of timothy rust on different hosts 

 varies slightly, those produced on barley being considerably smaller than those 

 on more congenial hosts. 



A heart rot of celeiy caused by bacteria, H. WoEi[ALD (Jour. Southeast. Agr. 

 Col. Wye, No. 22 (1913), pp. 457-413, pis. 4, fig. 1).—A somewhat detailed ac- 

 count has already been noted (E. S. R., 31, p. 542) of the organism there de- 

 scribed as BaciUvs apiovorus n. sp., the cause of a celery rot. It is thought 

 probable, as the result of recent studies described, that several bacteria may be 

 concerned in the production of bacteriosis in celery. 



The chief protective measures recommended are the burning of plants affected, 

 rotation, and control of attacks by snails, slugs, nematodes, and biting insects. 



A bibliography is appended. 



Dissemination of bacterial wilt of cucurbits, F. V. Rand ( U. S. Dept. Agr., 

 Jour. Agr. Research, 5 (1915), No. 6, pp. 257-260, pi. 1). — A preliminary note is 

 given of investigations conducted to throw some light on the mode of hiberna- 

 tion of the bacteria which cause the wilt of cucurbits and of developing some 

 practical method of control. 



Cucumber plants were grown in cages so constructed as to prevent the en- 

 trance of injurious insects, and the results obtained indicate that the wilt bac- 

 teria are carried over the winter by the hibernating beetles and inoculated into 

 the cucumbers as they feed upon the young leaves. From results obtained in 

 four cages, it appears that not all hibernating beetles can carry the disease, but 

 only those which have previously fed upon wiltetl plants. Negative evidence Is 

 also afforded by the fact that in all the cages from which beetles were excluded 

 the plants remained free from the disease in two fields where it was very 

 prevalent. 



Some ginseng troubles, E. A. Bessey and J. A. McClintock (Michigan Sta. 

 Spec. Bui. 72 (1915), pp. 8-15, figs. 5). — Notes are given on the black rot of 

 ginseng, due to Sclerotinia panacis, the control of daniplng-off of ginseng seed- 



