Page 124 - Agriculture_Form_3

Agriculture for Secondary Schools

FOR ONLINE READING ONLY

Figure 7.5: Cowpea bruchids and the damage they cause
Common diseases in cowpea and their management
Cowpeas are also affected by fungal, bacterial, and viral diseases. The most
common include leaf spot, powdery mildew and mosaic virus.

Leaf spot: This is a disease that is caused by either a bacterium or a fungus.
It appears as brown or black spots on leaves. It spreads through water splash
and infected crop remains. It reduces leaf area and weakens the plant. It can
be managed by crop rotation, removing infected plants, and using disease-free
seeds. Figure 7.6 shows symptoms of leaf spot disease on a cowpea plant.

Figure 7.6: Symptoms of leaf spot disease on cowpea
Powdery mildew: This is a fungal disease which appears as a white powder
on leaves and stems. Severely infected plants have distorted leaves, stunted
growth and reduced yield. It spreads in dry weather and is managed by using
resistant varieties and applying suitable fungicides. Figure 7.7 shows symptoms
of powdery mildew disease on a cowpea plant.

Student’s Book Form Three 115

17/09/2025 14:12
AGRICULTURE F3.indd 115 17/09/2025 14:12
AGRICULTURE F3.indd 115