Hibiscus esculentus
Fusarium Wilt (fungus – Fusarium oxysporum F. sp. vasinfectum): The most obvious symptom is a typical wilt, followed by death. Infected plants may be stunted and yellow. The fungus invades the root system and colonizes the vascular system. In doing so, water movement is blocked and toxins from the fungus alter normal cell function. Cutting the base of the stem reveals a dark woody portion. No control is available other than a long rotation. All varieties are susceptible.
Root Knot Nematode (nematode – Meloidogyne sp.): Okra is highly susceptible. Root becomes enlarged and distorted. See the section on root knot nematodes. No resistant varieties are available.
Leaf Spot (fungi – Alternaria sp., Ascochyta sp., Cercospors malayensis, Phyllosticta hibiscina): There are several leaf spotting organisms which attack okra. However, none have been shown to cause economic loss. No control is recommended.
Blossom and Fruit Blight (fungus – Choanephora cucurbitarum): Young fruit and blossoms are attacked by the fungus which gives them a “whiskery” appearance. Infected plant parts are reduced to a soft rotten substance. Disease development is favored by warm, humid weather. Spray with an approved fungicide.
Seedling Disease (fungus – Rhizoctonia sp.): This disease is more likely to occur if okra is planted before soils warm sufficiently in the spring. See the Seedling Disease Section for more information.
Virus: A whitefly-transmitted geminivirus was detected by Dr. Judith K. Brown in okra from Tamaulipas, Mexico (adjacent to the Lower Rio Grande Valley) in the fall of 1994. Fruit has irregular yellow areas which follow a longitudinal alignment. The initial symptom on young leaves is a diffuse, mottled appearance. Older leaves have irregular yellow areas which are interveinal. The disease is associated with the presence of whiteflies. The nature of the geminivirus has not been determined, nor has the presence of other viruses been ruled out. Preliminary experiments by Dr. Brown suggest the virus is not seedborne. There are no control measures. Submitted by Tom Isakeit, 5/7/95.
Cotton Root Rot (fungus – Phymatorichum omnivorum): Infected plants die suddenly from mid-summer to fall. Leaves usually remain attached to the plant. For more information see the Cotton Root Rot Section.
Charcoal Rot (Fungus – Macrophomina phaseolina): (See section on Charcoal Rot)
Southern Blight (fungus – Sclerotium rolfsii): (See section on Southern Blight)
