Concept:Maize stem borer is a pest that remains inside maize stems, so cultural removal and destruction of infected plants give the most effective control.
Explanation:The maize stem borer attacks the stem and feeds inside the plant.
Larvae and pupae stay hidden within the stems of affected maize crops.
Chemical sprays often fail because the insect is protected inside the stem.
Uprooting affected crops removes the entire plant from the field.
Burning the uprooted crops kills the larvae and pupae through heat.
This destroys the pest's breeding source and interrupts its life cycle.
As a result, the borer cannot spread to healthy maize plants.
Timely removal and burning of infected crops is, therefore, the most effective control measure.
Rodenticides target rodents, nematicides target nematodes, and fertilizers improve plant nutrition.
None of these options directly controls maize stem borer.
Answer:A. affected crops are uprooted and burnt