Growth cracks develop when the tuber’s internal tissue grows faster than its surface tissue. This problem is associated with conditions that cause rapid internal
growth, such as drought followed by a rainy period.
Also, growth cracks may develop when an excessive amount of fertilizer is available to the plant.
Growth cracks are also characteristic of some viral diseases and herbicide damage.
Thumbnail cracks are shallow splits in the tuber skin of well-hydrated tubers that have been exposed to drying conditions.
Elephant hide or alligator hide refers to thick, coarse russetting and cracking of the tuber skin. It has been associated with soils that contain undecomposed
organic matter, salts or certain agricultural chemicals.