Farmers Guide: Secret Behind Rotting Of Sweet Potatoes In Garden

By Spy Uganda

Sweet potatoes can rot in the garden for several reasons, typically related to environmental conditions, soil health, and pests. Here are the main factors that can cause sweet potatoes to rot:

1. Excessive Moisture or Poor Drainage

• Overwatering or heavy rain can cause the soil to stay too wet, leading to waterlogged conditions. Sweet potatoes thrive in well-drained soil, and when their roots are constantly wet, they can rot.
• Poor soil drainage can also create a similar problem. If the soil doesn’t drain properly, the tubers stay wet and susceptible to rot.

2. Soilborne Diseases

Several diseases can cause sweet potatoes to rot, including:

• Fusarium Wilt: Caused by the Fusarium fungus, this disease can lead to rot in the roots, especially under moist conditions. It causes the leaves to yellow and the plant to wilt, which can also lead to the tubers rotting.
• Rhizopus Rot: This is a common fungal infection that attacks sweet potatoes, causing soft, mushy rot. It thrives in warm, wet conditions, especially after harvesting, but it can also affect the roots in the garden.
• Southern Blight: A soilborne fungus that can infect sweet potatoes and cause root rot, especially in warm, humid conditions.

3. Insects and Pests

• Root-knot nematodes: These tiny pests can infect the roots of sweet potatoes, causing swelling and damage. While the sweet potato may initially grow, the damaged roots become more susceptible to rot.
• Wireworms and root borers: These pests can also damage the sweet potato roots, creating entry points for pathogens that cause rot.

4. Improper Harvesting

• If sweet potatoes are harvested too early or too late, they may be more prone to rotting. Early harvests can result in immature tubers that are not fully formed and more susceptible to disease. On the other hand, leaving them in the ground too long can lead to over-ripening and softening, which makes them more prone to rot.

5. Inadequate Air Circulation

• Sweet potatoes require good air circulation around their roots. If they are planted too closely together or if there is insufficient space for air to flow, moisture can build up around the tubers, leading to rot.

6. Overcrowding

• When sweet potato vines are crowded or not spaced properly, they can shade the soil and reduce airflow, creating a humid, stagnant environment where rot can develop.

7. Infection During Storage

• If sweet potatoes are harvested and stored improperly, they can begin to rot even after being harvested from the garden. Sweet potatoes should be cured in warm, dry conditions before storage to improve their shelf life. If stored in too much moisture or in an area with poor ventilation, the tubers are more prone to rot.

8. Temperature Fluctuations

• Extreme temperature changes, particularly early frosts or late-season cold snaps, can damage the sweet potatoes, making them vulnerable to rot. They should be harvested before the first frost to avoid this.

How to Prevent Rotting in Sweet Potatoes:

1. Improve Drainage: Ensure the garden soil has good drainage by amending it with organic matter or planting in raised beds to avoid waterlogging.
2. Avoid Overwatering: Water the plants consistently but not excessively. Sweet potatoes prefer slightly dry conditions once established.
3. Space the Plants: Properly space sweet potato plants (usually 12–18 inches apart) to ensure good air circulation and reduce the risk of rot.
4. Practice Crop Rotation: Rotate sweet potatoes with other crops to reduce the risk of soilborne diseases.
5. Control Pests: Use natural pest control methods to manage insects like root-knot nematodes and wireworms.
6. Harvest Properly: Harvest sweet potatoes at the right time—before the first frost—and handle them carefully to avoid bruising or injury.
7. Cure the Tubers: Cure the harvested sweet potatoes in a warm (80-85°F or 27-29°C), dry area for about 10-14 days before storing them to promote healing and improve storage life.
8. Store Correctly: Store cured sweet potatoes in a cool, dry, and well-ventilated area. Avoid storing them in the fridge, as cold temperatures can cause the starches to turn into sugars, affecting the texture and flavor.