Peb. ax, 19x6 
Soilstain , or Scurf , 0 / Sweet Potato 
1001 
SUMMARY 
Soilstain, or scurf, is a disease of the epidermis of the sweet-potato 
root. The disease occurs in every sweet-potato section, East and South, 
and is probably generally distributed. It is more abundant in the heavier 
soils, especially where manure is used as a fertilizer. 
Soilstain reduces the market value of the mature roots. It reduces 
the average yield by attacking also the younger rootlets and stunting 
their development. 
Soilstain is a disease of the underground parts of the plant. In stor¬ 
age the disease spreads by contact and is favored by moist, poorly 
ventilated houses. 
The fungus Monilochaetes infuscans is difficult to culture, because it 
is a very slow grower and is readily overrun by associated saprophytes. 
The conidiophores of M. infuscans are distinct from the mycelium, the 
older growth of which is also dark. The conidia are borne in chains 
which readily break up when moistened or disturbed. 
LITERATURE CITED 
(1) Ceements, F. E. 
1909. The Genera of Fungi. 227 p. Minneapolis. 
(2) Engler, Adolf, and Prante, K. A. E. 
1897-1900. Dienatfirlichen Pflanzenfamilien ... T. 1, Abt. 1, 1897; T. 1, Abt. 
1**, 1900. Leipzig. 
(3) Halted, B. D. 
1890. Some fungous diseases of the sweet potato. N. J. Agr. Exp. Sta. Bui. 76, 
32 P- 
(4) Harter, L. L. 
1916. Sweet-potato scurf. In Jour. Agr. Research, v. 5, no. 17, p. 787-792,1 pi. 
(5) Saccardo, P. A. 
1911. Sylloge Fungorum ... v. 20. Patavii. 
(6) Smith, Erwin F. 
1905. Bacteria in Relation to Plant Diseases, v. 1, 285 p., 146 fig., 31 pi. 
Washington, D. C. (Carnegie Inst. Washington Pub. 27.) 
(7) Stevens, F. L. 
1913. The Fungi Which Cause Plant Disease. 754 p., illus. New York. 
(8) TaubEnhaus, J. J. 
1914. Soil stain and pox, two little known diseases of the sweet potato. (Ab¬ 
stract.) In Phytopathology, v. 4, no. 6, p. 405. 
-and Manns, T. F. 
1915. The diseases of the sweet potato and their control. Del. Agr. Exp. Sta. 
Bui. 109, 55 p., 65 fig. Literature, p. 48-5 1 * 
(9) 
