Bacteria wilt

3. Bacteria wilt (Ralstonia solanacearum)

The disease is due to soil bacterium living in humid and heavy soil. The disease penetrates through roots or injuries. The disease spreads by water, agricultural tools or disease plants transplanting.

To test for this condition: cut the lower stem of the infected plant, place the cuts in water. Milky stream of bacteria will be observed oozing from the cut ends.

Symptoms and damage

• Leaves start to wilt then after a few days the entire plant wilt while leaves maintain their green • Wilting begins with youngest leaves especially during warm or hot weather conditions • Wilted leaves do not fall. • Invaded roots may root from secondary bacteria • Discolouration of the internal vascular tissue of the stem.

Sudden wilting, no yellowing

Management

Internal discolouration of vascular tissue

• Use varieties resistant to BW • Encourage proper soil drainage • Crop rotation with crops which are tolerant to BW e.g. cereals crops • Avoiding planting successive solanaceae crops like tomatoes, pepper, and eggplant. • Control root knot nematodes and root feeding pests