| SYMPTOMS |
CAUSES |
CONTROLS |
| Plants wilt or are stunted; leaves
turn yellow |
• Dry soil |
• Supply water |
| • Root rot (fungal disease) |
• Remove old plant debris; rotate; plant
in well drained area |
| • Root knot nematode |
• Rotate; soil pasteurization |
| • Poor fertility |
• Amend soil as needed |
| Failure to set pods |
• High temperatures, causing blossoms to
drop |
|
| • Dry soil |
• Supply water |
| • Wet soil, causing lack of oxygen to
roots |
• Do not overwater; plant in well drained
soil |
| • Mature pods left on vines, causing seed
production rather than pod set |
• Pick pods regularly |
| Rust-colored powdery spots surrounded by
yellow haloes form on leaves, stems, and pods |
• Rust (fungal disease) |
• Resistant varieties; use registered
fungicide; remove old plant debris |
| Soft, watery spots on leaves, stems, and pods;
white moldy growth on these plant parts; plants wilt and die |
• White mold (fungal disease) |
• Use registered fungicide; rotate;
remove old plant debris; plant in well-drained and ventilated
area not planted to beans last year |
| Thin, white powdery growth on leaves and pods |
• Powdery mildew (fungal disease) |
• Resistant varieties; use registered
fungicide; rotate; remove old plant debris |
| Small, brown spots surrounded by yellow haloes
on leaves: leaves wither |
• Halo blight (bacterial disease) |
• Avoid overhead watering which spreads
the disease; use fixed copper bactericide if available locally |
| Leaves skeletonized; copper-colored beetle
with black spots or yellow grubs with spines |
• Mexican bean beetle |
• Hand pick the beetles and grubs or use
registered insecticide |
| Leaves with shiny white spots |
• Spider mites |
• Use insecticidal soap spray or
registered miticide |
| Young leaves curled, distorted, and yellow;
clusters of tiny insects on leaves and stems |
• Aphids |
• Use registered insecticide or hard
stream of soapy water |
