PLATE 4 
A. —Radial cut of fleshy root (variety Key West) showing severe symptoms of 
internal breakdown. The longitudinal passages are interrupted by diaphragms. 
The lining of the cavities shows a brown discoloration. 
B. —The same as above, except that the breakdown has not yet reached the stage 
showing brown discoloration. Cavities shaded in drawing. 
C. —Cross section of fleshy root shown in A. Notice the denudation of the larger 
bundles. 
D. —Cross section of fleshy root shown in B. This is a typical view exhibited by 
sweet potatoes affected with internal breakdown. 
