12 Journal of Agricultural Research voi. iv. no. i 



JiMSON WEED {Datura iatula). — On April 25, 191 4, three mature plants 

 of Jimson weed growing in pots at the greenhouse were sprayed with 

 a spore suspension of the Phoma fungus. These plants were placed 

 beneath bell jars for a period of 10 days, but no leaf spotting developed. 



Garden peas (Pisum sativum) and beans (Phaseolus vulgaris). — 

 Young plants, 10 to 12 cm. high, growing in greenhouse pots, were 

 inoculated on April 16, 191 4, by spraying \\ath a spore suspension of 

 the Phoma fungus. The spraying was done with an atomizer on a 

 cloudy day at a room temperature of 78° F. The plants were not cov- 

 ered. In two weeks no spotting had occurred upon either pea or bean 

 leaves. 



A second experiment with bean plants was tried similar to the preced- 

 ing, except that the plants were placed beneath bell jars after the spray- 

 ing. At the end of 10 days there was no infection. 



Pepper plants (Capsicum annuum). — In February, 191 4, some pepper 

 plants just coming into blossom were sprayed with the Phoma spore 

 suspension. The plants were kept under bell jars for 10 days. No 

 infection could be seen after a period of three weeks. Other pepper 

 plants were sprayed March 10, 1914, and placed in an infection cage. 

 There was no infection in two weeks' time. 



REISOLATION OF THE FUNGUS 



From plants inoculated in greenhouse. — Spots have been repeat- 

 edly produced by means of inoculations upon tomato fruit growing on 

 greenhouse plants, and the Phoma fungus has been plated out from the 

 discolored tissue. The following inoculations are typical of many others. 

 In February, 1914, diseased spots were produced upon green tomato 

 frtiit by means of needle-prick inoculations. From tissue cut from the 

 spots the fungus was recovered in agar plates. Diseased spots were 

 produced upon mature fruit growing on greenhouse vines (Pi. Ill, fig. 2)^ 

 and the fungous was isolated in pure cultures on February 2, 1914. The 

 leaves of young and of mature tomato plants were diseased as a result 

 of being sprayed with a fungous suspension in January, 191 4. From 

 the spotted leaf tissue taken from both young and old leaves the Phoma 

 was isolated by means of agar plate cultures. 



From plants inoculated in laboratory. — Green, partially ripened, 

 and fully matured tomato fruits were picked from vines growing in the 

 greenhouse and brought to the laboratory for inoculation. Upon these 

 tomatoes spots were readily produced in four to seven days by means 

 of needle-prick inoculations of the Phoma, and the fungus was recov- 

 ered in pure cultures from tissue taken from the spots. 



From plants inoculated in field. — From tomato fruit, stem, and 

 leaf tissue diseased through inoculation of the Phoma the fungus was, 

 obtained in pure culture by means of agar plates (Aug. 19, 191 4). 



