Page 34 - Agriculture_Form_3

Agriculture for Secondary Schools

Maize weevil: The maize weevil is a significant postharvest pest that damages
stored maize by boring holes in grains and feeds on the internal content. The
pest can also infest dried grains while still in the field. This leads to grain weight
loss and reduced seed viability. Management strategies include drying grain to a
moisture level below 13%, using airtight containers or hermetic storage bags to
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limit oxygen, and treating maize with insecticides. Figure 2.6 shows the maize
weevil and damaged maize.

Figure 2.6: Maize weevil and is damage on maize
Earworm: The earworm affects maize by feeding on silks and kernels, leading
to a reduction in grain quality. The damage caused by these larvae creates entry
points for secondary infections, such as fungal pathogens, which can further
affect the crop. To manage earworm infestations, resistant maize hybrids should
be used, which offer natural tolerance to the pest, and insecticides to minimise
losses. Figure 2.7 shows the earworms and the damage they cause.

Figure 2.7: Earworms and the damage they cause
Common maize diseases and their management
Maize can be affected by various diseases weakens the plant, reduce its growth,
and lower grain quality. Each disease shows different symptoms on the plant.
Recognizing these symptoms helps in selecting appropriate management
strategies to protect the crop. Common maize diseases include lethal necrosis,
common rust, smut and bacterial leaf streak.

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