Bean and cowpea mosaic
Leaves show light and dark green patches, pucker and curl down, and the pods are few and twisted.
Crops it strikes
What you see
When to act
Check growing tips and young pods twice a week for aphid colonies, most of all in the first month. Spraying the aphids does little against this virus, so put the effort into clean seed and early roguing.
Before you spray
No spray cures it, and aphids pass the virus in seconds, before any insecticide acts. Plant clean seed, pull sick plants early and keep new plantings away from old ones.
The insect that spreads it
No spray cures a sick plant. What slows the spread is keeping the bean aphid (cowpea aphid) down, early, before it carries the disease to healthy plants.
How to prevent it
- Plant clean seed, and never save seed from plants with mottled, curled or blistered leaves. Both viruses travel in seed.
- Grow a resistant variety where one is sold.
- Pull mottled plants as soon as you see them, before aphids carry the virus to their neighbors.
- Keep new plantings away from older bean and cowpea fields, and clear legume weeds and volunteers.
- Plant a border of corn or sorghum around the field and use silver mulch to keep winged aphids off.
Natural enemies and biological help
- Ladybirds, hoverfly larvae and small parasitic wasps hold aphids down. Avoid broad sprays that kill them.
Where this comes from
Not sure it is this one?
Many diseases look alike. Send a photo to Anee, the smart farm technician in anee.io. She reads it with your crop, its age and the weather, and tells you what it most likely is and what to do first. In Tagalog or English.