1923] 



LEHMAN — POD AND STEM BLIGHT OF SOYBEAN 143 



Soybean stem and petiole. — Inoculated March 31, 1921. On 

 April 5, mycelium profuse, loose, high, growing down the stem, 

 white on the petiole and white with yellow-green in small areas 

 on the stem; no pycnidia. April 15, on stem, mycelium loose, 

 high, profuse over entire stem, white except at top which is 

 yellowish; pycnidia just appearing. On petiole, mycelium pro- 

 fuse over upper one-fourth, white with yellow-green areas, 

 remainder of petiole natural brown, mottled with black areas; 

 pycnidia numerous over entire stem, exuding spores in watery 

 white droplets. May 15, same as for previous date except 

 spore droplets dried to brown color. 



Inoculated August 18, 1921, with strain P 11 and kept in a 

 covered glass dish. August 23, mycelium profuse on upper half 

 of stems, rather sparse on petioles, white with yellow-green in 

 small areas where profuse; pycnidia numerous on petioles, 

 fewer on stems; no spores exuded. September 22, pycnidia 

 numerous on both stem and petioles, exuding pycnospores 

 which are drying to a yellow or brown color. 



Potato plugs. — Autoclaved in special tubes constricted to hold 

 the plug out of water. Inoculated March 31, 1921. April 5, 

 mycelium loose, high, profuse, white, spreading over entire plug. 

 April 15, mycelium profuse, dense, high, white with considerable 

 brown about the point of inoculation. May 15, mycelium 

 densely matted in places, high in others, matted over surface of 

 liquid; black stromatic masses present but no pycnidia. July 

 20, no pycnidia. 



Sweet potato. — Fifty grams of potato sliced and autoclaved 

 in enough water to cover, in 750-cc. flasks. Inoculated March 

 31, 1921. On April 5, mycelium profuse, moderately dense, 

 white, spreading rapidly. April 15, mycelium covering surface 

 of substratum, greenish, yellowish, with dirty brown areas, 

 droplets of brown fluid on surface. May 16, mycelium dirty 

 brown with white areas ; black, brown, and white areas on bottom 

 and sides of flask. Black stromatic masses present but contain 

 no pycnospores. July 21, mycelium a dirty brown with white 

 areas and black stromatic masses. Reverse side of culture 

 mostly black with white areas; very few pycnidia with pycno- 

 spores. Pycnospores have characteristic droplets, are some- 



