Patna: Sugarcane farmers across Bihar have been urged to take immediate preventive action against the growing threat of smut disease and top borer infestation, which experts warn could cause significant damage to the state’s sugarcane crop this season.
The Sugarcane Industry Department has issued a formal advisory, alerting cultivators to the heightened risk of infection during the current high-temperature phase from late March through June. Smut disease, a major fungal infection, thrives in temperatures ranging from 32°C to 38°C and is particularly prevalent in poorly managed stubble crop fields.
Smut: A fast-spreading fungal threat
Smut disease visibly affects the crop by producing long, black, whip-like structures at the top of the plant, which are loaded with millions of spores. Infected leaves become narrow and date-palm-like in appearance. The disease causes a sharp decline in sugarcane quality and severely reduces juice and sugar content.
To curb its spread, the department recommends removing infected plants along with their roots and sealing them in plastic bags for safe disposal. Farmers are also advised to apply a fungicide—propiconazole—at a dose of 1 gram per litre of water. This should be sprayed twice at intervals of 15 to 20 days.
Critically, farmers should avoid using seeds from infected fields for future sowing. Crop rotation is strongly recommended in such areas, and it is advisable not to plant sugarcane there for at least two years to eliminate fungal spores through lack of a suitable host.
Top borer poses additional danger
Alongside smut, sugarcane is also under threat from the top borer insect, which bores into the central veins of sugarcane leaves, halting plant growth and causing the ‘bunchy top’ symptom. To mitigate the risk, the department suggests intercropping with spice crops and installing light traps positioned 15 cm above the crop canopy to monitor and capture the pests.
Effective crop management, timely monitoring, and following these preventive measures can help protect the sugarcane yield and boost both crop quality and farmer incomes.
Dr Rajendra Prasad Central Agricultural University’s Sugarcane Research Institute confirmed a sharp rise in cases of both smut and top borer in sugarcane fields across Bihar this year. The institute has appealed to farmers to inspect their fields weekly and implement pest and disease control protocols without delay.
