Symptom

• Seedlings, leaves, stem and fruits are affected
• Spots on leaves, stems and fruits
• White blister like spots in the margins of leaves and turn brown.
• Wilting of leaves and shoots, streaks on stems and petioles.
• Small, water soaked spots with white halo on fruits.
• Centre of spots become slightly raised
• tan coloured and rough
• Cankers develop and form cracks
• slimy bacterial ooze through cracks.
• Vascular discolouration.

Stem infection	Fruit infection

Causal Organism :

• Clavibacter michiganensis subsp. michiganensis (Smith) Davis

Pathogen :

• Gram-positive, non-motile, rod-shaped, aerobic bacterium

Survival and Mode of Spread

Survival :

• In Infected debris

Primary spread:

• Infected plant debris and seed

Secondary spread:

• Rain splash

Favourable conditions

• Soil temperature - 28°C
• High humidity or persistent dew
• Moist weather with intermittent showers

Integrated Disease Management

• Field sanitation
• Crop rotation with non host crops
• Use of disease free seeds
• Disinfection of tools and implements
• Removal of weeds

Source of Information

• https:www.apsnet.org
• Crop production guide – Horticulture 2020.

Acknowledgement