Banana Erwinia rot: Erwinia carotovora sub sp. carovora
Symptom:
- This disease is more pronounced on young suckers leading to rotting and emitting of foul odour
- Roting of crown region is a characteristic symptom followed by epinasty of leaves, which dry out suddenly
- If affected plants are pulled out it comes out from the crown region leaving the corm with their roots in the soil
- Splitting of pseudostem is common in late stage of infection in cultivars Robusta, Grand Naine and Thella Chakkerakeli
- When affected plants are cut open at collar region yellowish to reddish ooze is seen
- In early stage of infection dark brown or yellow water soaked areas are more in the cortex area
- In advance stage, the interior lesions may decay to such extent that cavities surrounded by dark spongy tissues are formed
- This soft rotting may spread radially towards growing point through the cortical tissues. The rotten corm emits a foul smell.
Identification of pathogen:
- The pathogen is a Gram-negative bacterium with peritrichous flagella and it is a rod shaped bacterium that lives alone or aggregates into pairs and chains
- The pathogen is soil borne and enters through wounds and also through leaf sheath of suckers
- The disease can be spread by infected plant debris, plant wounds and injuries. Hot and damp weather with plenty of rainfall trigger the disease to occur. Water is required for the bacteria to invade into the plant.
Management:
Cultural method
- Good drainage and soil conditioning can control the disease to some extent.
- Plant disease free suckers.
- Remove infected plants immediately.
- Remove plant residues after harvest.
- Practice crop rotation by using crops that are not susceptible to the bacterial rot disease like soybean, forage legumes and small grains. Banana should not be grown along with onion and other vegetables.
- Control nematodes and other insect pests that serve as vectors of the bacteria to invade the plant tissues.
- Use of rhizomes with dead central buds and active lateral buds prevents the appearance of the disease.
- Avoid planting during the rainy season and use of bigger suckers (more than 500g) for planting.
Chemical method
- Dip suckers in copper oxychloride (40g/10l)+ streptocycline (3g/10lit) for 30 min before planting.
- Drench with 6g/tree or Sodium hypochlorite 10% or Bleaching powder 20g /litre/tree. Immediately irrigate after application.
- Repeat twice at 10 days interval.
Source-
- TamilNadu Agritech Portal