Barrier or border crops

Definition

Plants sown at the perimeter or within a crop field to impede, divert, or reduce the immigration of herbivorous insects and other pests from adjacent habitats, or to concentrate them where they can be more easily managed. These plantings may act through physical obstruction, preferential host attraction (trap-crop function), non-host repellency, or provision of natural enemy habitat. The distinction between 'barrier' (emphasizing interruption of movement) and 'border' (emphasizing edge placement) is often blurred in practice, with both terms used interchangeably in the entomological literature.

Etymology

Example

In East African maize systems, Napier grass (Pennisetum purpureum) planted as a border crop attracts and traps ovipositing stem borers (Busseola fusca, Chilo partellus) away from the main crop, while simultaneously fostering parasitoid populations that spill over into adjacent maize.

Synonyms

• perimeter plantings
• buffer strips (in pest-management context)

Related Terms

• trap crop
• push-pull system
• Intercropping
• crop rotation
• habitat management
• Integrated Pest Management
• dispersal barrier

Usage Notes

'Barrier crop' sometimes implies a non-host or repellent function that physically or chemically blocks pest entry, whereas 'border crop' more neutrally denotes spatial placement at field edges, which may serve attractive, repellent, or habitat-provisioning roles. Specialists may use the terms interchangeably; context determines intended mechanism. Effectiveness varies with pest flight behavior, crop phenology, and landscape structure. Not to be confused with windbreaks or conservation buffers designed primarily for erosion control or biodiversity without explicit pest-interception goals.