Degeneration in Sugarcane Varieties: Does the Sugar Industry Realize it?

Generally, it is believed that sugarcane grows normally in the absence of stalk infecting pathogens causing red rot, wilt, smut or fungal diseases. Although degeneration occurs in sugarcane due to systemic build-up of non-fungal pathogens, the canes are harvested as healthy canes. The degenerated canes showed 30–50% reduction in cane weight and also a similar loss in juice yield. Even though physiological yield potential of sugarcane is more than 300 t/ha, an average cane yield of only 84 t/ha is achieved in India. Yield gap due to the degeneration caused by the non-fungal pathogens, especially viruses associated with mosaic and yellow leaf disease, ratoon stunting bacterium and grassy shoot phytoplasma are ignored under field conditions. Improved molecular diagnostics combined virus elimination through meristem culture showed a practical approach to manage varietal rejuvenation in sugarcane and demonstrated restoration of yield potential of major varieties. The industry should realize this major impact to sugarcane and take corrective measures to sustain the cane cultivation in India.