PEST MANAGEMENT DECISION GUIDE: GREEN AND YELLOW LIST
Common bacterial blight on Bean
Xanthomonas axonopodis pv. phaseoli Chiwawu cha nyemba
- Use disease free certified seed
- Practice crop rotation with non host crops like maize and groundnuts for at least 2-3 years to break disease cycle
- Remove volunteer bean plants after harvest and before planting as they act as a source of inoculum
- Deep ploughing after harvest to bury the infected crop debris and encourage decomposition
- Suspend field operation when plants are wet to avoid spreading the disease
- Do not save and use seeds from the previous infected fields
- Start monitoring two weeks post seedling emergence and weekly until pod formation
- Look for water soaked dark spots under the leaf
- Leaf spots enlarge and merge to form a large brown irregular lesion with a yellow margin
- Stems rot at the first node where cotyledons are attached causing the plant to break
- On pods look for sunken lesions with reddish brown boarder
- Under wet conditions look for yellow slimy bacterial exudates that ooze out of the lesion
- Carry out direct controls as soon as symptoms are seen
- Uproot and burn all infected plants
- Spray recommended insecticides indicated in the Yellow Direct Control section
- Use personal protective equipment when handling and applying pesticides, follow the label recommendations. Do not eat, drink, smoke when mixing or applying pesticides.
Foliar application of Copper oxychloride 860g/Kg WP (Kocide) at 300-400g per 100 litres of water. Copper oxychloride is a bactericide with contact, multisite action. FRAC group: M1
WHO Class II (Moderately Hazardous). Apply at 14 day intervals. Do not breathe spray. Harmful if swallowed. Very toxic to aquatic organisms.
CREATED/UPDATED: July 2018
PRODUCED BY: Plantwise
©CAB International. Published under a CC-BY-SA 4.0 licence.