DISEASES OF PLANTS. 447 



types, Volga, proved more highly resistant than the best secured hi 1912. From 

 the second generation of selected heads sufficient seed was obtained iu 1913 for 

 a wider qualitative test of resistance on the part of these varieties. 



Decay of celery in storage, D. Reddick {Abs. in Phytoimthology, 4 (1914), 

 No. 1, p. 45). — Some experiments are reported upon to determine the keeping 

 quality of celery affected by the late blight disease {Septoria petroselina) when 

 placed under modern .storage conditions. When stored at a temperature of 31° 

 F. from October 15 to December 23, 1912. there was no appreciable sjjread of 

 the disease. 



The author also reports the deterioration of a carload of celery which wag 

 stored in November at a temperature of 31 to 32°. A study showed that this 

 lot was infected with Sclerotinia libertiana, and cultures of the fungus were 

 obtained which were used for inoculations with positive results. 



Some points in the life history of Phytophthora on ginseng, J. Rosenbaum 

 (Abs. in Phylopathology, 4 (1914), No. 1, p. 44)- — -^ disease of ginseng tops 

 due to Phytoi)lithora has been previously noted by Hori (E. S. R., 19, p. 752). 

 Some additional observations are reported and it is said that the disease on the 

 leaves and stems, as well as a very serious root disease, is caused by the same 

 organism. The Phytophthora organism may first appear on the tops, work its 

 way down by way of the stems, and eventually rot the root. Or it may first 

 appear on the root, and after rotting this, may travel upward into the stem 

 and appear 'in the tops. The conidia of the fungus may be washed down into 

 the soil and infect the root, provided the latter is not too deep below the surface. 



Fusaria of potatoes, C. D. Sherbakoff (Abs. in Phytopathology, 4 (1914), 

 No. 1, pp. 43, 44)- — This is the result of a taxonomic study of the species of 

 fungi of the genus Fusarium as they occur in Solnnum tnberostom. 



The author isolated 120 strains which seemed morphologically different, but 

 when grown on artificial and natural media about 70 of them were found to be 

 simply morphological variations. Of the remaining 50, many were identified 

 with the species described by Wollenweber (E. S. R., 29. p. 444). 



A study of the annual recurrence of Phytophthora infestans, I. E. Melhus 

 (Abs. in Phytopathology, 4 (1914), No. 1, p. 54). — A large number of potato 

 tubers infected with P. infestans were planted in northern Maine under field 

 conditions to determine the possibility of infection through the tuber. This 

 locality is said to be favorable for the annual recurrence of the blight, but the 

 land used in this experiment had not grown a crop of potatoes for at least five 

 years. 



Some of the diseased tubers produced plants which became infected by the 

 mycelium in the parent tuber. Above the surface of the soil the fungus pro- 

 duced spores and infected the foliage and neighboring shoots in the same and 

 adjoining hills. It 'is considered that this experiment demonstrated that seed 

 potatoes affected with P. infestans may function in starting an epidemic of 

 late blight. 



Some recent studies on new or little-known diseases of the sweet potato, 

 J. J. Taubenhaus (Abs. in Phytopathology, 4 (1914), No. 1, pp. 50, 51). — In 

 addition to the black rots previously described (E. S. R., 30. p. 150), accounts 

 are given of stem rot due to Fusarium batatis, ring rot, which recent studies 

 have shown is a form of soft rot (Rhizopus nigricans) , a white rust caused by 

 Cystopus ipomoEce pandurance, which is said to be of considerable importance, 

 and a new leaf spot, which is attributed to a species of Septoria as j'et unde- 

 scribed. 



Blossom-end rot of tomato, C. Bkooks (Abs. in Phytopathology, 4 (1914)^ 

 No. 1, p. 49). — The author states that this disease is usually not accompanied 

 by any organism, although bacteria and fungi are pi*esent in late stages of the 



