1923] 



LEHMAN — POD AND STEM BLIGHT OF SOYBEAN 135 



their dense foliage. The Haberlandt variety was used for this 

 test. The plants were still green, the pods varying from nearly 

 full size to very small and immature. Sixty-two pods of various 

 sizes and stages of development on one plant were inoculated by 

 inserting mycelium and spores into the wall of the pod, using care 

 not to puncture the cavity of the pod. Thirty-two pods on 

 another plant in the same stage of maturity were similarly 

 wounded but not inoculated. The inoculations were made on 

 August 18 and on September 22, the interval usually hot and 

 dry being marked by subnormal rainfall and high temperatures. 

 Fifteen pods were found with scattered pycnidia over the entire 

 pod or about the wounded area. Others of the inoculated pods 

 which bore no pycnidia on their surface had their seeds attacked 

 and even covered with a mycelial weft. The diseased pods 

 were well distributed over the entire plant. None of the pods 

 on the check plant showed infection, the wounds healing and the 

 pods maturing in an apparently normal manner. 



On 4 different occasions, seedlings growing in large test-tubes 

 (20 X 2.5 cm.) on sterile blotting-paper moistened with Shive's 

 3-salt nutrient solution have been inoculated by atomizing the 

 seedlings with a water suspension of the pycnospores. Under 

 these conditions, uninfected plants live 4 weeks or more and 

 attain a stem length of 6 inches, pushing vigorously against the 

 cotton plugs and developing the first pair of true leaves. When 

 inoculated with a spore suspension of pycnidia of the soybean 

 pod- and stem-blight organism, the seedlings became diseased 

 and pycnidia developed in large numbers on the stems and coty- 

 ledons. 



During the summer of 1921, inoculations were made at various 

 times on plants growing in 4-gallon jars in the greenhouse. The 

 results of the most important of these are given in the following 

 paragraphs : 



On May 23, 1921, two plants bearing 4 pods each were inocu- 

 lated by atomizing pods, stems, and leaves with a spore suspension 

 of strain 7. On June 24, 1 pod of each plant was found to be 

 covered with pycnidia. The remaining 6 pods were plucked 

 and put into a moist chamber, whereupon 5 developed many 

 pycnidia in the course of 5 days, the sixth pod remaining free. 



