Page 36 - Agriculture_Form_3

Agriculture for Secondary Schools

Maize smut: This is a fungal disease that causes swollen galls filled with black
spores on maize ears, stalks and tassels. The disease leads to stunted growth and
reduced crop yield. The galls eventually burst, spreading spores to nearby plants.
Management includes removing the infected plants and properly destroying
them, practising crop rotation with non-host crops, and planting resistant maize
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hybrids to minimise infection risk. Figure 2.10 shows the symptoms of maize
smut on the maize cob.

Figure 2.10: Symptoms of smut on maize cobs

Bacterial leaf streak: Bacterial leaf streak is a disease that causes water-soaked
lines on maize leaves. The leaves then turn yellow, dry out, and the plant makes
less food through photosynthesis (Figure 2.11). The disease spreads quickly
through splashing water and infected plant parts, especially in wet conditions.
It can be managed by avoiding overhead irrigation, using clean seeds, planting
resistant varieties, and rotating crops. Keeping the field clean also helps to stop
the disease from spreading.

Figure 2.11: Symptoms of bacterial leaf streak on maize leaves

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