symptoms
Root rot is a disease where the roots of the plant decay.
Swollen and distorted base of stem can be noticed.
Deep dark rot extendingdeep into tuber and forming elliptical cavities can also be seen.The affected parts show growth of white mold.
Management
Adopt proper field sanitation.
Select only disease free vines for planting.
Follow crop rotation.
For more information please contact with our toll free number 1800 425 1661
Dept of Agriculture Development 
SFAC Kerala