Sweet potato weevil (Cylas formicarius)

A serious pest of sweet potato that infest the crop in the field, in storage sheds, and in propagation beds.The adults and larvae of the weevil damage the tuber by feeding and making tunnels just under the skin.

Integrated control

1) Remove and destroy the crop residues of the previous crop.
2) Use healthy and weevil-free planting materials.
3) Apply Eupatorium odoratum leaves as mulch @ 3 t/ha at 30 DAP.
4) Trap adult weevils using sweet potato pieces (of about 6 cm diameter) of 100 g size, kept at 5 m apart during 50 to 80 DAP at 10 days interval. Tubers may be cut and kept inside wire cages to avoid rat damage.
5) Use pheromone traps (3Z Dodecenyl 2E butenoate).

Harvesting

The duration of the crop depends on the variety; but in general, the crop can be harvested in about 3.5-4 months after planting. Harvest the crop when leaves begin to turn yellow and the tubers mature. The maturity of tuber can be ascertained by cutting fresh tubers. The cut surface will dry clear if the tuber is mature and becomes dark green if immature. Harvest the crop by digging out the tubers without causing injury. The average yield is 20-25 t/ha.