FIG. 26. SWEET POTATO DISEASES. 



a. Black rot at place of a bruise, b. black shank, c. showing a pycnidium of the 

 black rot fungus, d. dry rot, e. cross section through /, to show the effect of the 

 disease on the root, /. Java black rot surface view, showing strings of spores oozing 

 out from the center of spot, g. cross section through .diseased sweet potato root to 

 show pycnidia of the fungus Diplodia tubericola. 



