Castor is the only crop where all types of pest incidence can be witnessed. so it is called as trap crop. Castor crop can be planted even in very small numbers along the borders of the field. The castor crop should be monitored very often and in case of any new pest incidence then it must be eradicated at intial stages.
Castor should not be planted at large numbers and also should be planted at enough spacing. it should not be planted at the middle of the field.
Castor can be planted along the borders of groundnut field at 2meters spacing. This helps in destroying the protenia worms.’
2) COW PEA:
Cowpea can be planted either as a border crop or as intercrop. This crop is suitable for the growth of aphids. When the aphids incidence is higher then to feed on them many beetles and beneficial insects visit the feild. This helps in protecting the main crop from pest attack.
Maize has many predators within it. When planted in borders and as a intercrops these predators in the maize trap the pest that attacks the main crops.
Maize is a suitable crops for the predators like birds. These birds feed on the insects in the fields and so when maize is planted as an intercrop it is highly beneficial in controlling pests like leafhopper and boll worms.
4) PEARL MILLET:
When pearl milled is sowed as an intercrop along with the groundnut the attack of leaf roller, thrips and moths can be controlled effectively.
5) YELLOW FLOWERED CROPS:
- Marigold’s roots secrete a chemical substance. This helps in destroying the root nematodes. This chemical substance has effect around 1 sq.m and so when planted between the crops helps in reducing the root nematode attack.
- Planting the sunflower in the cotton field helps in reducing the green leaf hopper attack.
- When daincha is planted along with the sugarcane crop the stem borer attack is controlled.
- To control termites infestation, we can plant crops like vetiver, euphorbia, erukku, castor in the field.
- When mustard is planted along with the vegetable crops like cabbage, cauliflower mustard act as a trap crop and destroys the diamond back moth attacking the main crop.
- Planting mint along the border helps in controlling rodents like rat.