960 
Journal of Agricultural Research voi.xxvii,No.xa 
com was first germinated in Petri dishes (PI. 1) on a weak nutrient 
glucose agar. Only seedlings found to be free from infection at the end 
of a five to six day period were used. It was discovered that disease-free 
seed was very difficult to secure, but in these investigations some com 
seed samples were found which after surface treatment were practically 
100 per cent disease free. The seedlings were transferred from the plates 
to the jars with sterile forceps. During this transfer some of the soil in 
the jars was exposed to the air in the laboratory, but all possible pre¬ 
cautions were taken to prevent infection. The table on which the work 
was done, the hands, and all dishes and instruments used were swabbed 
with a 1 to 1,000 HgCl 2 in 50 per cent alcohol solution. At the time of 
planting, the soil in the jars was inoculated with the various organisms. 
This inoculation was obtained from pure cultures of these organisms 
grown on weak nutrient glucose agar. A sufficient quantity of the culture 
was added to the jars to insure a thorough inoculation. All experiments 
were run in duplicate. After the com was planted the tops of the jars 
were covered with sterile cotton. It was necessary to exercise care when 
the plants were coming through to see that the cotton cover did not inter¬ 
fere with their growth. The jars were kept properly supplied with 
water; the optimum moisture condition was met by supplying 30 per 
cent moisture at the time of planting and keeping this replenished every 
other day. 
STUDIES WITH ROOTROT SICK SOIL 
Preliminary studies were made on two soils taken from adjacent 
fields on a near-by farm. Previous to the growing of the com crop in 
1921, both fields had been part of a peach orchard for 12 years. Field 
No. 1 produced much rootrot and fallen com in 1921, while field No. 2 
produced a good com crop. It is not known by the writers what fertilizer 
or cultural treatments the fields had had during the 12-year period pre¬ 
vious to the experiment, but is is not thought likely that a very high de¬ 
gree of fertility was maintained. Field No. 1 was the lower of the two 
fields, and was poorly drained. The soil was a fine sandy loam, light 
brown in color. Large areas of nut grass (probably Cyperus rotundus) 
were growing in this field. Field No. 2 was somewhat higher than No. 1 
and was better drained. The soil was a fine sandy loam, very dark in 
color. These soils were plated and examined for pathogenic fungi; at¬ 
tention was given only to the four organisms, namely, Fusariim, monili - 
forme , Gibberella saubinetii , Diplodiazeae and the so-called Cephalosporium 
sacchari. The soil from field No. 1 was found to be apparently free from 
the above organisms, while field No. 2 showed an average of 300 colonies 
of F. moniliforme per gram. The other organisms did not show in the 
cultures. Total nitrogen and total organic matter determinations were 
run on each of these soils. The results were as follows: 
Nitrogen: Per cent. 
Field No. 1..0.040 
Field No. 2....046 
Organic matter: 
Field No. 1... 2.60 
Field Nq. 2..... 2.96 
The soil was brought into the laboratory from each of these two fields. 
The soil from field No. 1 (the nonresponsive sick field) was put into two 
3-gallon pots labeled iA and iB. The soil from field No. 2 was put into 
similar pots and labeled 2A and 2B. Pot 1A received a treatment of 7 % 
