Mysore Trumpetvine with Crown Gall? Rare but Treatable
Thunbergia mysorensis
Crown gall is a bacterial disease caused by Agrobacterium tumefaciens that affects over 140 species of plants. The bacteria insert DNA into plant cells, causing them to divide uncontrollably and form large tumor-like growths (galls) primarily on roots, stems, and at the soil line. These galls restrict water and nutrient flow, severely impacting plant health and potentially killing the plant.
ð Symptoms
- âĒ Large, rough, woody tumor-like growths (galls) at the base of stems
- âĒ White masses of callus tissue on roots and crown
- âĒ Galls appearing at or just below soil line
- âĒ Swellings on stems, limbs, trunks, or roots where wounds occur
- âĒ Stunted growth due to restricted water and nutrient flow
- âĒ Decline in overall plant vigor and health
â Possible Causes
- â Infection by Agrobacterium tumefaciens bacteria through wounds
- â Physical damage during planting, grafting, or cultivation
- â Soil insect feeding creating entry wounds
- â Root damage from excavation or mechanical injury
- â Use of contaminated tools or infected nursery stock
- â Bacteria surviving in soil from previous infected plants
ð Treatment
Quick Fixes
Step 1
Identify and mark all visible galls on crown and roots
Step 2
During dry season, use sterilized sharp knife or pruning saw to cut galls
Step 3
Cut at least 1-2 cm into healthy wood tissue around each gall
Step 4
Remove all gall tissue completely without leaving infected remnants
Step 5
Allow cut surfaces to dry in open air for 24-48 hours
Step 6
Apply copper-based wound dressing to exposed areas
Step 7
Monitor weekly for 4-6 weeks for regrowth
Organic Treatment
Step 1
Inspect plants carefully before purchase and select only certified disease-free stock
Step 2
Dip bare roots or drench potted plants with Agrobacterium radiobacter K-84 (commercial product: Galltrol) before planting
Step 3
Sterilize all pruning tools with 70% alcohol or 10% bleach solution between cuts
Step 4
Apply copper octanoate as a preventive soil drench in high-risk areas
Step 5
Remove small galls by cutting into healthy wood during dry season, minimizing healthy tissue removal
Step 6
Expose cut surfaces to air and sunlight for natural drying
ðĄïļ Prevention
- â Inspect all nursery stock carefully and reject plants with any galls
- â Sterilize all pruning tools between plants using 10% bleach solution
- â Avoid wounding plant crowns and roots during cultivation
- â Control root-chewing insects to prevent wound creation
- â Improve soil drainage to reduce bacterial activity
- â Use certified disease-free planting material
- â Solarize soil with clear plastic for 4-6 weeks before planting
- â Remove and destroy infected plants immediately - do not compost
ðą Care Guide: Mysore Trumpetvine
ð§ How to Water
Water every 4-6 days during the growing season, thoroughly soaking the root zone. In winter, reduce watering significantly to encourage blooming. Always allow the top inch of soil to dry slightly between waterings to prevent root rot.
âïļ Lighting
Provide full sun (at least 6 hours of direct sunlight daily) for the best flowering. In hot climates, light afternoon shade can be beneficial. The plant requires bright light to produce its iconic cascading flower clusters.
ðŠī Ideal Soil
Plant in well-draining, humus-rich soil with a slightly acidic to neutral pH (6.0-7.0). Amend clay or sandy soils with compost or perlite to improve drainage and fertility.
Sources & References
- Agrobacterium tumefaciens - Wikipedia
- Crown gall | UMN Extension
- Crown gall: Causes, Symptoms & Control | RHS Advice
- Crown Gall / UC Statewide IPM Program
- Agrobacterium tumefaciens - Crown Gall | UMass
- RHS - Thunbergia mysorensis
- Green Cover Initiative - Indian Clock Vine
- Mahindra Nursery - Thunbergia Care Guide
- Wikipedia - Thunbergia mysorensis
- Gardenia.net - Thunbergia mysorensis