RUGOSE MOSAI 
it 
. ENTIRELY . . 
IN UPPER LEAVES OF ALL SHOOTS 
IN UPPER LEAVES OF SOME SHOOTS 
\M/LD MOSAIC 
Fig 
IG . i — Diagrammatic representation of the results of inoculation with rugose mosaic and of proximity in 
1923 to plants with this disease. Each circle represents a hill (drawn to scale as of one foot m diameter of 
each circle), with disease indicated as explained in the legend. See also Plate 9, A In Section W 1, 
planted on May 15, and observed on July 31, row 12 was planted with controlhealthy stock rows 13 to 15 
with seed from rugose mosaic plants, and rows 16 to 18 as for row 12. Section W 6 was planted on May 19, 
as a control plot, from the same stock as the control rows in Section W-l, and was observed on Aug 14. 
Section W-7 was planted on June 19 and 22 with the same control stock as above, was inoculated on July 
14 and was observed on August 14. In this section, hills of row 1 were inoculated with juice from the roots 
of rugose mosaic plants, row 2 from the leaflets, and row 3 from the stems and petioles, row 4 from the 
shoots (stems and leaves), row 5 from the seed tubers, and row 6 with tap water. On this section each row 
consists of 10 four-hill tuber units, and one or two hills in each tuber unit were inoculated, these being the 
two right-hand or west hills in each tuber unit in rows 2, 3, and 4. In section W-6, each row consists of 20 
two-hill tuber units. For further discussion see the text on pp. 507 and 509 
