- The Bacterial Blight of Coffee (BBC) , also known as Elgon/Solai
Die- Back is caused by a bacterium Pseudomonas syringae pv Garcae
- The bacterium is found on all healthy parts of the coffee tree.
- BBC is confined to a few coffee growing areas, (Solai in Nakuru and around Mt Elgon - North Rift).
- Recently, a few cases have been reported in the East of Rift.
Conditions favorable to the disease
Cool, wet weather triggers the multiplication of the bacteria
Rapidly causing an epidemic.
Management of BBC
- Cut off infected twigs and branches.
- Plant shade trees and wind breaks on exposed sides of BBC areas.
- Observe field hygiene by disinfecting tools used for pruning infected trees with a suitable disinfectant such as Kerol 0.1 % , Lysol 3%.
- Avoid planting materials from known BBC areas.
- Critical spray time is just before, during and after flowering especially when these coincide with wet weather.
- Complete first spray by mid-February and continue through the rains at two week intervals and after rains at three week interval .
Details on recommended chemicals
- Lesions appear on leaves, water soaked margin and black at start of infection. Leaves eventually dry up and roll inwards turning brown.
- Dead and dried leaves do not shed but remain attached to the plant.
- Terminal bud is attacked. Infection then extends downwards, resulting in die-back.
On young succulent branches:
- Infection starts from the stipules, then entire node is attacked. Infection spreads to internodes. Branch then dies above the blackened node.
- Internodes infection as a result of hail damage or through wounds caused by sucking insects. This is not a common
On flowers and pinhead stage:
- Entire trusse or pinheads may be attacked and appear black and water soaked.
- Flowers and pin-heads shrivel and turn black.
- The entire crop may be lost.
Highlights on Good Agricultural/Hygienic Practices
- Avoid indiscriminate use of fungicides to prevent pesticide residue accumulation.▪ Sterilise all implements used on diseased plants.
- Severe infection leads to death of twigs and branches which reduces yield and bean quality.
- Only recommended fungicides should be used.
Avoid planting materials from BBC known areas