Okra Blossom Blight

Choanephora cucurbitarium, a common fungus

Also known as Whisker rot

Blossom blight on okra [Credit: Gerald Holmes, California Polytechnic State University at San Luis Obispo, Bugwood.org]

Host Plants:

On Crops: Okra, cucumber, squash

Where Found:

Warm temperate climates with abundant rainfall in late summer

Description:

This unusual disease is also called whisker rot, because infected blossoms become covered with a white cottony mass that develops black whiskers. These are the pin-like fruiting structures of the fungus. The fungus grows on the flower petals, and is active when weather conditions are very damp and temperatures exceed 75F (24 C).

Damage:

If the wet weather ends and you gently pull the infected blossom away, the pod may be worth saving if its tip has not darkened with rot. Prune off pods that feel soft at the tip.

Preventing Problems:

Grow okra at wide spacing, so that the leaves of neighboring plants barely overlap. After the soil has warmed in summer, mulch beneath plants to create a barrier between the soil and the plants’ foliage. Prune back plants in late summer to push out new growth. After the plants begin blooming, use soaker hoses instead of sprinklers to water thirsty plants.

Managing Outbreaks:

Harvest pods that grew from infected blossoms while they are small, because wet weather can cause the tip of the pod to start rotting. Clear away nearby vegetation that may slow the drying of okra foliage and blossoms after summer rains.

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