|Parsnip Root Rot|
To prevent this problem in the future the grower needs to ensure root crops are not planted back into this area for at least 3 years.
Areas where root crops are to be planted should be amended to improve drainage. This is best accomplished with a coarse organic matter - 1/4 inch in diameter. Don't use sand as this will most likely result in a concrete-like soil. Large particle of organic matter can result in crooked roots.
Avoid cultivating around root crops. Any damage to the 'skin' of the root will be a spot where these disease organisms can invade.