Biocontrol of Sugarcane Insect Pests and Diseases

Sugarcane is a semi-perennial crop, which facilitates conservation and multiplication of natural enemies of sugarcane crop. Biological control along with cultural and mechanical control can keep pests population below economic injury level.

Borers

First two broods of early shoot borer damage the crop during pre-monsoon period. Top borer third brood, which appears in the beginning of July, causes maximum damage. Stalk borer causes damage during monsoon and post-monsoon period, and remains active during winter. Gurdaspur borer breeds and damages during July to October and diapauses during winter and pre-monsoon period. Root borer damage is sometimes noticed during pre-monsoon period. All the borers breed and feed from April to October, but Gurdaspur borer from July to October.

Sucking Pests

Pyrilla is a sporadic pest. Most years, its population remains below economic injury level by its natural enemies: Epiricania melanoleuca, Tetrasticus, Ageniasperus, other parasitoids and predators. Black bugs damage the ratoon crop during pre monsoon period. In July, its population decreases rapidly. White fly sometimes damage the crop, but mostly its population remains low. Mealy bug, thrips and mite are considered minor pests. All these sucking pests feed and breed from April to November.

Diseases

Red rot, wilt and smut are the major diseases of sugarcane. There is no effective control of these diseases, so we can control diseases by developing resistant varieties and clean cultivation.

We should try to control all the pests with cultural, mechanical and biological control, conservation augmentation inoculation of natural enemies. Always try to cultivate comparatively resistant varieties to diseases and pests. Avoid chemical control and it may be used only when it is very urgent. By adopting this strategy, we can minimize hazards of pesticides and in this way we will be able to get an eco-friendly agro ecosystem.

Plant Crop

1. Plant the crop after rauni irrigation before March 15th, so that sugarcane shoots may grow enough to withstand the damage of early shoot borer in May and June.

2. Use seeds from absolutely disease and insect pest free seed plot.

3. Grow varieties fairly resistant to diseases (red rot, wilt) and borers.

4. Strip the seed cane thoroughly to expose pests.

5. Do not plant sugarcane in disease affected field (red rot for one year and wilt for three years)

6. Plant the crop in rows 90 cm apart with trench planting method.

7. Collection of egg masses and roughing of dead heart of borers. Give special attention to second brood of top borer.

8. Release Trichogramma chilonis for early shoot borer and stalk borer at 20,000 per acre at 10 days interval from mid April to end June.

9. Release Trichogramma japonicum for top borer at 20,000 per acre at 10 days interval from mid April to end June.

10. Frequent irrigation during pre-monsoon period decreases early shoot borer incidence and withheld irrigation when second brood of top borer appears decreases top borer incidence.

11. Light earthing during April-May decreases early shoot borer incidence.

12. Judicious use of irrigation and fertilizer decreases lodging and stalk borer incidence.

13. Redistribution and colonization of Epiricania melanoleuca can help to decrease Pyrilla incidence.

14. Release Trichogramma chilonis at 20,000 per acre at 10 days interval from July to October (10-12 times) to control stalk borer.

15. Rogue out Gurdaspur attached canes (specially gregarious phase) from July to September at weekly interval.

16. Remove dry leaves from August to September to decrease stalk borer incidence.

17. Prop up the crop in the end of August to avoid lodging.

18. At harvest, cut the canes and water shoots below the ground level.

19. Heavily infested crop with top borer should be harvested by the end of February, and with stalk borer by the end of January, to decrease the overwintering population.

20. Rogue out and burn the diseased canes. Uproot the entire clumps and not merely the affected stalk.

21. Crush the crop affected with diseases early and plough up the fields soon after harvesting the crop. Collect and burn the stubbles.

22. Do not ratoon the diseased crop.

23. Do not ratoon heavily infested crop with Gurdaspur borer. Plough up the fields not meant for ratooning and destroy the stubbles before June to kill diapausing larvae.

Ratoon Crop

24. First brood of all the pests appear in ratoon crop during pre-monsoon period, then all the pests migrate to plant crop. It is very important to suppress pest population at ratoon crop, before it can migrate to plant crop.

25. Survey sugarcane crop regularly for insect pests and diseases infestation to take necessary control measures timely.