Bui. 818, U. S. Dept. of Agriculture. 
Plate IV. 
Fig. I. —Lettuce Plants from Bench Sections Nos. 3 and 4, Shown in 
Plate III, Figure 2. 
Note (A) the white, healthy, vigorous root systems from plants grown in treated section No. 3, as 
compared with (B, C, and D) the nematode infe4ted and blackened, Rhizoctonia-diseased roots 
from untreated section No. 4. 
Fig. 2— Tomato Plants Grown in 4-Inch Pots of (A,) Treated and Untreated 
Infested Soil as Compared with (B,) Treated and Untreated Fresh Green- 
house Soil, Experiment Series II. 
Note the pronounced differences in size, vigor, and number of plants between the front check pot 
and the back treated pot. For details of results, see the text. 
