Okra Charcoal Rot Information
Charcoal rot of okra is caused by a fungus in the soil called Macrophomina phaseolina. It lives in the soil, so it can build up each year and attack and infect roots year after year. The infection is most likely to set in when drought conditions have caused stress in okra plants. Signs of okra with charcoal rot include the characteristic ashy, gray appearance of infection on the stems that give the disease its name. Look for shredded stems with small black dots on the parts of stem that remain. The overall appearance should be like ash or charcoal.
Preventing and Treating Okra Charcoal Rot
If you are growing plants, like okra, that are susceptible to charcoal rot, it is important to practice good cultural practices for prevention of infection. The fungus builds up in the soil, so crop rotation is important, changing out susceptible plants with those that won’t host M. phaseolina. It is also important to remove and destroy any plant tissue and debris that was infected at the end of the growing season. Since the fungus has the most impact on drought-stressed plants, make sure your okra plants are well watered, especially during times when rainfall is less than normal. Agricultural researchers have found that certain substances can be useful in reducing the charcoal rot infection in okra plants as well as in increasing growth and yield. Salicylic acid, benzothiadiazole, ascorbic acid, and humic acid have all been found to be effective, especially at higher concentrations. You can use any of these to soak seeds before sowing them in the spring to prevent infection caused by fungus in the soil.
