Initially, indistinct olive-coloured spots can be observed on the lower side of the leaves. Especially older leaves, which are closer to the ground are affected by the disease. Light brown to grey mouldy fungal growth may develop on affected leaf surfaces. As the disease progresses, spots become necrotic and can also appear on the upper leaf surface. Infected leaves eventually become dry and wither. Stem and fruit may also be affected by similar symptoms. Under severe infestation, the plant might defoliate completely. Symptoms might be confused with C. malayensis.
The leaf spots are caused by the fungus Pseudocercospora abelmoschi. It survives and overwinters on infected plant debris in the soil and thus infects roots and lower leaves of the Okra plants. The spores are spread secondary via wind, rain, irrigation and mechanical tools. Leaf spots are very common during the humid season (flowering stage), as the fungi favour warm and wet weather.
To this day, we are not aware of any biological control method available against this disease. If you know of any successful method to reduce the incidence or the gravity of the symptoms, please contact us.
Always consider an integrated approach with preventive measures and biological treatments, if available. Spray fungicide on the lower side of leaves in the afternoon. Use protective fungicides as copper oxychloride @0.3%, Mancozeb @0.25% or Zineb @0.2% a month after sowing and repeat this procedure at fortnightly intervals, depending on severity. Carbendazim 50 DF @0.1% at 15 days interval also showed promising results in controlling the disease.