Trap cropping is the planting of a trap crop to protect the main cash crop from a certain pest or several pests. The trap crop can be from the same or different family group, than that of the main crop, as long as it is more attractive to the pest. There are two types of planting the trap crops; perimeter trap cropping and row intercropping. Perimeter trap cropping (border trap cropping) is the planting of trap crop completely surrounding the main cash crop. It prevents a pest attack that comes from all sides of the field. It works best on pests that are found near the borderline of the farm. Row intercropping is the planting of the trap crop in alternating rows within the main crop.
Advantages of trap cropping
1. Lessens the use of pesticide
2. Lowers the pesticide cost
3. Preserves the indigenous natural enemies
4. Improves the crop’s quality
5. Helps conserve the soil and the environment
Table 1. Examples of trap cropping practices
| Trap crop | Main crop | Method of planting | Pest controlled |
| Alfalfa (Meyer, 2003) | Cotton | Strip intercrop | Lygus bug |
| Basil and marigold (MMSU, 2003) | Garlic | Border crops | Thrips |
| Castor plant (Hasse, 1986; 1987) | Cotton | Border crop | Heliotis sp. |
| Chervil (Ellis; Bradley, 1996) | Vegetables Ornamentals | Among plants | Slugs |
| Chinese cabbage, mustard, and radish (Facknath, 1997; Muniappan; Lali, 1997) | Cabbage | Planted in every 15 rows of cabbage | Cabbage webworm Flea hopper Mustard aphid |
| Beans and other legumes | Corn | Row intercrop | Leafhopper Leaf beetles Stalk borer Fall armyworm |
| Chick pea (Grundy; Short, 2003) | Cotton | Block trap crop at 20 plants/ sq m (Brown, 2002) | Heliotis sp. |
| Collards (Boucher; Durgy, 2003) | Cabbage | Border crop | Diamondback moth |
| Corn (Hasse, 1986; 1987) | Cotton | Row intercrop, planted in every 20 rows of cotton or every 10-15 m | Heliotis sp. |
| Cowpea (CIKS, 2000) | Cotton | Row intercrop in every 5 rows of cotton | Heliotis sp. |
| Desmodium (ICIPE, 2003) | Corn Cowpea Millet Sorghum | Row intercrop | Stemborer Striga |
| Dill and lovage (Ellis; Bradley, 1996) | Tomato | Row intercrop | Tomato hornworm |
| Green beans (Ellis; Bradley, 1996) | Soybean | Row intercrop | Mexican bean beetle |
| Horse radish (DA, Philippines, 1997) | Potato | Intercrop | Colorado potato beetle |
| Hot cherry pepper (Boucher; Durgy, 2003) | Bell pepper | Border crop | Pepper maggot |
| Indian mustard (Cornell University, 1995) | Cabbage | Strip intercrop in between cabbage plots | Cabbage head caterpillar |
| Marigold (French and African marigold) (Vann; Kirkpatrick; Cartwright, 2004) (Dofour; Guerena; Earles, 2003) | Solanaceous Crucifers Legumes Cucurbits | Row/strip intercrop | Nematodes |
| Medic, Medicago litoralis (Miles, C.; et al., 1996) | Carrot | Strip intercrop in between carrot plots | Carrot root fly |
| Napier grass (ICIPE, 2003) | Corn | Intercrop Border crop | Stemborer |
| Nasturtium (Ellis; Bradley, 1996) | Cabbage | Row intercrop | Aphids Flea beetle Cucumber beetle Squash vine borer |
| Okra (Hasse, 1986; 1987) | Cotton | Border crop | Flower cotton weevil |
| Onion and garlic | Carrot | Border crops or barrier crops in between plots | Carrot root fly Thrips |
| Radish (Ellis; Bradley, 1996) | Cabbage family | Row intercrop | Flea beetle Root maggot |
| Rye (OIKOS, 2003) | Soybean | Row intercrop | Corn seedling maggot |
| Sesbania (Naito, 2001) | Soybean | Row intercrop at a distance of 15 m apart | Stink bug |
| Sickle pod (OIKOS, 2003) | Soybean | Strip intercrop | Velvet bean caterpillar Green stink bug |
| Soybean | Corn | Row intercrop | Heliotis sp. |
| Sudan grass (ICIPE, 2003) | Corn | Intercrop Border crop | Stemborer |
| Sunflower (CIKS, 2000) | Cotton | Row intercrop in every 5 rows of cotton | Heliotis sp. |
| Tansy (DA, Philippines, 1997) | Potato | Intercrop | Colorado potato beetle |
| Tobacco (Hasse, 1986; 1987) | Cotton | Row intercrop, planted in every 20 rows of cotton | Heliotis sp. |
| Tomato (Makumbi, 1996) | Cabbage | Intercrop (Tomato is planted 2 weeks ahead at the plots’ borders) | Diamondback moth |
| Vertiver grass (van de Berg, Undated) | Corn | Perimeter crop | Corn stalk borer |
Tips for successful trap cropping
· Make a farm plan. This will guide you on where the trap crops are to be sown or planted.
· Learn to know and identify the pests.
· Select a trap crop that is more attractive to the pest than the main crop. Ask for assistance from your local agriculturist.
· Monitor your plants regularly.
· Immediately control the pests that are found in the trap crop. Prune or remove the trap crops once the pest population is high, otherwise they will serve as the breeding ground and the pests will attack the rest of your farm.
· Be ready to sacrifice your trap crop as an early crop and destroy them once pest infestation is high.
· Always keep farm records.
