1. Root rot and Damping off: Pythium, Rhizoctonia, Macrophomina
2. Southern blight: Sclerotium rolfsii
3. Cowpea mosaic :Virus
4. Fusarium wilt: Fusarium oxysporum

1. Root rot and Damping off: Pythium, Rhizoctonia, Macrophomina

	Symptom Symptoms vary and include rapid death of young succulent plants. Discoloration of taproots, longitudinal cracks of the stems, stunting, wilting and poor yields. Complete control of root rot and damping off is difficult, and no variety of cowpea is resistant to root rot. Persistent damp weather prior to development of the first true leaf and also the crowding of seedlings due to poor seed spacing may increase damping off.
Healthy and infected root

2. Southern blight:Sclerotium rolfsii

Symptom

• Southern blight is caused by a fungus that attacks roots and stems of cowpeas.
• The first visible symptom of southern blight is a progressive, yellowing and wilting of the foliage beginning on the lower leaves.
• The plant dies within a few days.
• A brownish vascular discoloration inside dead stem may extend several inches above the soil line.
• During warm, moist conditions, the coarse, white mycelium of the fungus makes characteristic fan-shaped patterns of growth on the stem at the soil line.
• In this white-mat of the fungus, numerous smooth, round, light-tan to dark-brown mustard seed-like bodies called sclerotia are formed.

3. Cowpea mosaic :Virus

Symptom Several viruses attack cowpea. A characteristic symptom of the mosaic disease is an intermixing of light and dark-brown areas. Mottled areas are irregular in outline and may follow the main veins. Infected leaves are generally smaller than healthy ones, and often there is a slight puckering and curling of leaf edges. Infected plants usually are more dwarfed and bushy and yields are reduced. Mosaic diseases can also result in malformed pods.

4. Fusarium wilt: Fusarium oxysporum

Symptom Fusarium wilt usually causes the lower leaves on one side of the plant to turn yellow. Infected plants usually are stunted and wilted as the organism develops in the food and water conducting tissues. Brick red tissue can be observed in the stem when it is split lengthwise.

Management

Fungal and viral diseases can be reduced by:

• Treating high quality seed with fungicides labeled for cowpeas.
• A four or five year rotation with other crops.
• In addition to the cultural practices listed above, bury previous crop debris and the sclerotia, to control Southern blight at least 6 inch deep as far ahead of planting as possible.
• Seeding into warm, well-prepared soils.
• Planting certified seed of resistant varieties.
• Controlling weeds.
• The removal of virus-affected plants.
• Spray any one of the systemic insecticide like Monocrotophos @0.1% to control the vector.
• When resistant varieties are not used, it is important that root-knot nematode control practices be followed since nematodes increase plant susceptibility to Fusarium wilt.