Gardening Articles: Care :: Pests & Problems
Diseases of Eggplant , Pepper, and Okra (page 2 of 2)
by National Gardening Association Editors
Common Diseases of Eggplant, Peppers, and Okra
The descriptions below will help you identify diseases affecting your crops. By following the recommended controls you may be able to catch the problem early on and check their progress.
Leaf spot shows up in various forms: leaves, stems, or roots develop small, yellowish-green to brown spots; old leaves may show water-soaked spots; fruit develop small, raised rough spots or rot spots, or fruit may fail to set. There are a few leaf spot diseases caused by various seed- and soil-borne fungi and bacteria. Control measures include use of disease-free seed, crop rotation, and avoidance of overhead watering.
Anthracnose appears on fruits as dark circular, sunken spots with black spores. It's a seed- and soil-borne fungus that can also be transmitted by infected plant debris. To control, use disease-free seed, do not cultivate when plants are wet, and rotate crops.
Mosiac symptoms include green-yellow mottling of leaves, which become curved and distorted; the plant is usually stunted; fruits are yellow or wrinkled with dark spots, or are small, bumpy, and off-colored. Aphids transmit the virus that causes mosaic. Gardeners may carry it from infected areas, and the disease can live on crop refuse. To control it, destroy infected plants, do not use tobacco while in the garden, wash hands with soap and water before handling plants, control insects that transmit the disease, and use resistant varieties.
Blossom end rot appears as a black, sunken ring on the base of a fruit. It's different from the other diseases because it's not caused by an organism, but by a nutrient deficiency. Large fluctuations in soil moisture can make roots unable to take up adequate calcium, and the cells at the fruit's growing tip die. To avoid blossom end rot maintain soil pH between 6.0 to 6.8, and maintain adequate, regular moisture by improving soil, spreading mulch, and watering deeply and evenly when needed.
Root knot nematodes produce galls (knots) on okra and pepper roots, which stunt and weaken plants. Root-knot nematodes are microscopic worms that live in the soil and can be transmitted on seeds. To control nematodes, rotate crops with grasses or legumes, and maintain a high level of soil organic matter.
Wilts show up as wilting leaves and plants, and eventually plants die. Fruits are few, small, and of poor quality. Wilts are caused by various fungi that live in the soil or on crop residues. Control via crop rotation, a high level of soil organic matter, and good drainage.
Photography by Iowa State University Extension Plant Pathology