Arrowroot with Southern Blight? Rare but Treatable

Maranta arundinacea

Susceptibility: Low Severity: High Difficulty: Medium

Southern Blight on Arrowroot: What to Know?

Southern Blight on Arrowroot (Maranta arundinacea) is a fungal condition with high severity. Arrowroot has low susceptibility to this disease. Southern blight is a devastating soilborne fungal disease caused by Athelia rolfsii (formerly Sclerotium rolfsii), affecting over 500 plant species including vegetables, ornamentals, and fruit crops....

Arrowroot is a medium-care plant. Recovery from Southern Blight takes approximately 21 days with proper treatment. As an indoor plant, ensure good ventilation to aid recovery.

Unlike most plants, Arrowroot has natural resistance to Southern Blight. Best treated with preventive measures rather than reactive treatment. Unlike bacterial infections, Southern Blight on Arrowroot can be managed with organic fungicides.

🔍 What Does Southern Blight Look Like on Arrowroot?

• Brown to black lesions on stem near soil line
• Water-soaked appearance on lower leaves
• Sudden and permanent wilting of entire plant within days
• White mycelium radiating from plant base onto soil surface
• Spherical tan to reddish-brown sclerotia (1-2mm)
• Yellowing and necrosis of foliage
• Crown and root rot
• On fruits: sunken yellow lesions turning water-soaked

❓ What Causes Southern Blight on Arrowroot?

→ Soilborne fungus Athelia rolfsii surviving through sclerotia
→ High temperatures (25-30°C / 77-95°F)
→ High soil moisture and relative humidity above 90%
→ Acidic soil (pH below 7, especially pH 2-5)
→ Spread through infested soil and plant debris
→ Contaminated tools, irrigation water, and transplants
→ Contaminated mulch or compost
→ Plant stress and stem injuries

💊 How to Treat Southern Blight on Arrowroot?

TLDR: Treat Southern Blight on Arrowroot with quick treatment (~11 days) or organic (~21 days). Arrowroot has low susceptibility to this disease.

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Quick Fixes

Step 1

Remove infected plants IMMEDIATELY with roots and soil

Step 2

Apply azoxystrobin drench to adjacent plants

Step 3

Spray mancozeb on base of all plants in area

Step 4

Drastically reduce irrigation

Step 5

Reapply fungicides every 7-10 days for 3 weeks

🌿

Organic Treatment

Step 1

Remove diseased plants and 3 inches of contaminated soil

Step 2

Solarize area with clear plastic for 6 weeks

Step 3

Incorporate compost rich in Trichoderma

Step 4

Adjust soil pH with lime

Step 5

Improve drainage and plant spacing

Step 6

Apply preventive bicarbonate spray biweekly

🛡️ How to Prevent Southern Blight on Arrowroot?

TLDR: Prevent Southern Blight on Arrowroot with 10 essential preventive care practices.

✓ Carefully inspect transplants for sclerotia before planting
✓ Avoid planting in fields with history of infestation
✓ Maintain soil pH above 7 (lime reduces sclerotial germination)
✓ Improve plant spacing to increase airflow
✓ Use high-quality mulches from reputable suppliers
✓ Rotate with non-host crops (corn, wheat, barley) for 2-3 years
✓ Avoid overwatering and excessive soil moisture
✓ Disinfect tools between plants
✓ Deep plow (8-12 inches) to bury sclerotia
✓ Remove symptomatic plants and weeds immediately

🌱 How to Care for Arrowroot to Prevent Southern Blight?

💧 How to Water

Water about once a week, keeping the soil evenly moist but never waterlogged; let the top layer dry slightly between waterings to avoid root rot. Use rainwater or filtered water since arrowroot is sensitive to lime and hard water.

☀️ Lighting

Provide bright, indirect light -- a spot within a couple of meters of an east- or south-facing window is ideal. Avoid harsh direct midday sun, which can scorch the leaves, and avoid deep shade, which slows growth.

🪴 Ideal Soil

Plant in a rich, organic, well-draining mix with a slightly acidic pH of 5.5-6.5. A blend of quality potting soil, compost, and perlite works well to hold moisture while preventing waterlogging.

Frequently asked questions

Can Southern Blight kill my Arrowroot?

Yes, without treatment, Southern Blight can be fatal to Arrowroot. Early detection and treatment are key.

How long does Arrowroot take to recover from Southern Blight?

With proper treatment, recovery takes approximately 21 days. Without treatment, it can take significantly longer.

Is Southern Blight contagious to other plants near Arrowroot?

Yes, Southern Blight can spread to nearby plants. Isolate the affected Arrowroot immediately.

See more: Arrowroot → See more: Southern Blight →