19221 OQO 



ROSEN — A BACTERIAL DISEASE OF FOXTAIL OOd 



Group number. — According to the most recent chart adopted 

 by the Society of American Bacteriologists (Conn, et al, II, '20), 

 the foxtail organism has the following index number : 5322-31220- 

 1333. 



Technical Description 



Pseudomonas alboprecipitans, 1 n. sp. 2 



Narrow rods with rounded ends, solitary or in pairs; average 

 measurement of single rods 0.6 by 1.8 \i, motile by a single polar 

 flagellum; no spores, zoogloea or irregular forms; capsules pres- 

 ent ; strict aerobe ; surface colonies on nutrient agar white, round, 

 somewhat raised, smooth, amorphous, sticky, margins entire, 

 surrounded by areas followed by a white precipitate on media 

 testing acid, as Ph 6.6; nitrates reduced to nitrites; ammonia 

 produced; indol and hydrogen sulphide not produced; no acid 

 or gas produced in the presence or absence of carbohydrates; 

 diastatic action strong ; no growth in Cohn's solution but growth 

 in Uschinsky's and Fermi's solutions is fair; minimum tempera- 

 ture about 0° C, optimum between 30 and 35°, maximum about 

 40°, thermal death point 41-43°; vitality on culture media 

 comparatively long ; not sensitive to drying or freezing ; not very 

 sensitive to sunlight; Gram-negative, not acid fast. Pathogenic 

 to Chaetochloa lutescens, C. geniculata, C. italica, Avena sativa, 

 Holcus Sorghum, H. Sorghum sudanensis, Hordeum vulgare, 

 Secale cereale, Triticum sativum, and Zea Mays. 



Summary 



The bacterial disease here described is common on yellow fox- 

 tail in Arkansas. No concerted effort has been made to discover 

 the disease on other grasses but artificial inoculations show that 

 the pathogen is infectious on wheat, oats, rye, barley, corn, Sudan 

 grass, millet, and perennial foxtail. 



According to the classification suggested by Smith (II, '05, p. 171) the com- 

 bination would be Bacterium alboprecipitans n. sp. 



'Pseudomonas alboprecipitans, sp. nov., aerobus; baculis asporis cylindrieis 

 singulis vel binatis apicibus utrinque rotundatis flagello uno polare mobile, baculis 

 solitariis 0.6X1.8 ^. 



Coloniae in agar-agar rotundatae albae leves, marginibus plenis; in culturis 

 acidi minimi zonae hyalinae factae sunt secutae a precipito albo. Gelatina non 

 liquef acit. Acidum et gas non ef ficiuntur. 



Habitat in foliis vivis Chaetochloae lutescentis, C. italicae, C. genicuJatae, 

 Tritici vulgaris, Secalis cerealis, Avenae sativae, Hordei vulgaris, Zcae Mays, 

 Holci Sorghi. 



Arkansas, Amer. bor. 



