Alligator skin

The Alligator skin condition is a well-known physiological disorder that affects the surface of sweet potato (Ipomoea batatas) tubers. It is characterized by the development of rough, scaly, and deeply cracked skin, which gives the root crop a distinct resemblance to the hide of an alligator.

This disorder is primarily attributed to environmental stress rather than a pathogen. The most significant trigger is fluctuating soil moisture levels during the critical period of tuber expansion. Rapid changes in water availability cause the tuber to grow unevenly, leading to the cracking of the epidermal tissues as they fail to keep up with the internal expansion.

Symptoms are easily identifiable upon inspection of the harvested crop. The surface of the sweet potato loses its smooth texture and becomes covered in a network of fissures that often develop a corky appearance. While the internal flesh of the potato usually remains edible, the marketability of the crop is severely reduced due to its unappealing appearance.

Environmental conditions play a decisive role in the development and spread of this disorder. Hot, dry weather that is followed by sudden heavy rainfall or irrigation creates a perfect scenario for the skin to rupture. Furthermore, soils with poor water retention or high levels of compaction can exacerbate the plant's stress response.

Effective prevention and control measures focus on maintaining a stable growing environment for the plants:

• Implement consistent irrigation schedules to prevent moisture stress.
• Improve soil structure with organic matter to enhance water retention and drainage.
• Select sweet potato varieties known for their resistance to root cracking.
• Apply mulch to regulate soil temperature and minimize moisture evaporation from the root zone.