Trap crops are plants grown to protect the main crop from pests. The trap crops attracts pest more than the main crop. Most of the insects will have an alternative host plant. The trap crop can be from the some family of main crop or from different family of the main crop. The trap crops will prevent the pest from reaching the main crop.
All the pests will have a preference to a particular crop stage; accordingly the trap crops need to be planted. In the main field trap crops can be planted in the boundary or as intercrops in rows. The advantages of trap cropping are reduce the use of pesticide, reduce the pesticide cost, Preserves the indigenous natural enemies, improves the crop's quality, helps to conserve the soil and the environment.
The pest that is attracted to the trap crops should be removed once the pest population is high, otherwise the trap crops will become breeding place of the pests.
Eg: For controlling the Fruit borer in Tomato, Marigold is used as trap crop