CONTROL OF BACTERIAL WILT 13 
Tobacco of good quality was produced on urea-treated soil, however, by grow- 
ing it in rotation with | year of corn in small plot trials completed in 1941 (fig. 5). 
This experiment was repeated in 1943 at five locations, in which the tobacco 
ripened and cured well. At one location where data were taken on plots in 
triplicate, the 1,000-pound rate of urea averaged 977 pounds of tobacco an acre 
that sold for $39.30 a hundredweight, a normal yield and value for the sandy 
loam soil on which the test was conducted. 
The quantity of urea required for wilt control, when used in combination with 
the corn rotation, was investigated on a total of nine replicates at the five loca- 
E; ili ps eo EE: eae 
Figure 5.—Control of wilt by a combination of rotation and urea treatment of 
the soil. A, Tobacco grown after 1 year of corn, badly wilted. 8B, Tobacco 
grown on soil treated with urea prior to planting corn, showing much less wilt; 
the leaves ripened and cured well. 
