844 EXPERIMENT STATION RECORD. 



Stem rot of sweet potato, L. L. Hartb:r and Ethel C. Field (Ztschr. Pflan- 

 zenkrank., 24 (1914), No. 4, pp. 204-201). — This is ii brief account of investiga- 

 fions which have already been noted elsewhere (E. S. R., 32, p. 50). 



Black rot, shed burn, and stem rot of tobacco, J. Johnson {Wisconsin Sta. 

 Research Bid. 32 {1914). pp. 6.^-86, figs. 7).— The results are given of studies 

 on some warehouse and curing house troubles of tobacco. 



The black rot, due to ^tcriginatori/.itis nigra, is said to cause considerable los.s 

 in the process of fermentation under certain conditions. The fungus requires 

 in its development a moisture content of 20 per cent or more, a temperature of 

 from 30 to 44° C. (86 to 111.2° F.), together with pror>er aeration. 



In order to control this disease regulation of warehouse conditions so as to 

 keep down the moisture content and provide proper temperature is recom- 

 mended. Fumigation with formaldehyde may also be adopted where the disease 

 has i)reviously been very prevalent. 



The author states that the difference between shed bum and stem rot, which 

 are due to one or more fungi, among them a species of Fusarium, appears to be 

 one of location rather than a difference in causal organisms. If the midrib is 

 attacked, the resulting decay is called stem rot. while if the leaf tissue is de- 

 cayed it is called shed burn. 



These diseases may be controlled by regulation of temperature and humidity 

 in the curing shed in connection with proi:)er ventilatiop- 



The yellow blight of the tomato, D. C. George (Washington Sta. Popular 

 Bill. 82 (1915), pp. 4)- — This is a popular bulletin based largely upon a previous 

 publication of the station (E. S. R., 32, p. 444). 



Fire blight, I. D. Cardiff (Washington Sta. Popular Bui. 80 (1915), poster). — 

 This i)ublication is intended to call attention to the prevalence of the fire 

 blight of pears, apples, etc.. and gives brief suggestions for control. 



Life history of a new species of Sph^rella, B. B. Higgins (Mycol. Centbl., 

 4 (1914), No. 4, pp. 187-193, figs. 2). — A fungus, said to be new and to cause a 

 disease of Primus pennsylvanica, is described under the name Mycosphwrella 

 mgerristigma. The name S. mgerristigma is, howevex', preferred. 



Roncet of grape, J. Bernatsky (Ztsclir. Pflanzenkrank., 24 (1914), ^'O. S, 

 pp.' 129-139, figs. 2). — The author, discussing this phenomenon and allied ab- 

 normalities describes the internal appearance of the deformed regions in cases 

 studied, and suggests possible causes, which it is said may differ considerably 

 as to character and mode of action. 



[Two fungus parasites of conifers in Scotland], W. Somerville (Quart. 

 Jour. Forestry, 9 (1915), No. 1, pp. 68, 69, pi. 1). — Chrysomyxa aWetis and C. 

 rhododendri are said to have been noted one or more times previously on conifers 

 at points in Scotland, and a watch for these fungi is recommended. 



Withertip of fir in Sweden, T. Lagerberg (Meddel. Stat. Skogsforsoksanst. 

 (Mitt. Forstl. Vers. Anst. Scliivcdens), No. 10 (1913), pp. 9-44, I-IV. figs. 19).— 

 This is substantially the same as a report already noted from another source 

 (E. S. R., 30, p. 453). 



On the mode of infection of larch canker and the possible means cf pre- 

 venting it, W. E. HiLEY (Quart. Jour. Forestry, 9 (1915), No. 1, pp. 7-17. pis. 

 3). — Among the Vv^ays in which Dasyscypha (Peziza) calycina may infect larch 

 are mentioned wounds made by frost, hail, the larch aphis (Chcrmes ahietis), 

 or abrasions due to movements of men, animals, or air, though the dangers from 

 such sources has, it is thought, been overestimated. 



Owing to the death of young branches the cankers of most direct importance 

 to foresters are those induced after the first two or three years of growth. 



