Current status and management of sugarcanesmut disease in North India

Sugarcane an important cash crop suffers from several fungal, bacterial, phytoplasmal and viral diseases. Of the fungal diseases, smut had been a major constraint to sugarcane production in most of the sugarcane growing tracts of the country. The disease is caused by fungus Sporisoriumscitamineum (Syn: Ustilago scitaminea).Primary transmission of the disease takes place trough infected setts. Earlier this disease was kept under control through heat therapy (Aerated steam therapy /moist hot air treatment) of seed canes by the sugar mills and sugarcane research centers. However, since last couple of years, sett treatment practice has been stopped and smut incidence increased by many folds. To know the current scenario of sugarcane diseases in the subtropical region, authors surveyed the reserved areas of 44 sugar mills in Haryana, Punjab, Uttar Pradesh, Bihar and Uttrakhand states during 2010-2019 crop seasons regularly. In Haryana, smut prevails as major disease in most of the sugar mills and its incidence is increasing rapidly. The disease incidence ranged from 1.0 to 40.0% in ratoons and traces to 9.0% in plant crops of varieties viz. Co 0238, Co 89003, CoH 116, CoH 119, CoH 150, CoH 152, CoH 156, CoH 160, CoJ 85, CoJ 88 and CoS 8436. In Shahabad area most of the fields of variety CoH 160 had severe smut incidence i.e. up to 40.0% in ratoon and 9.0% on plant crops. Similarly in the varieties Co 0238, Co 89003 and CoJ 88 cultivated under Punjab, traces to 11.0% incidence in ratoon and up to 5.0% in plant crops was found. Further, in western UP occurrence of smut was moderate to 6.5% in ratoon and traces to 1.5% in plant crops of cultivated varieties. The maximum disease incidence (T-2.5%) was noted in Harinagar (Bihar) on variety CoSe98231, whereas, under Laksar (Uttrakhand) it observed to a tune of 4.5% and 6.0% on varieties CoSe 03234 and CoSe 01434, respectively. In the light of observations recoded over the period, advisories were issued regularly to the sugar mills for its prevention and farmers of the state have adopted smut management practices i.e. roguing of smut whips followed by spray of Propiconazole 25EC @ 0.1%. Farmers and sugar mill officials of the state have been advised to adopt seed cane treatment practices with Sett Treatment Device, recently developed by ICAR-SBI, Coimbatore to combat this disease. The Haryana sugar Federation is also advised to promote sett treatment practice in the state. Since last four years all the Co-operative sugar mills have been running tractor driven sett treatment units for seed cane treatment at farmer fields to manage sett borne diseases. Since smut has emerged as a serious disease, sugar industry should take up the disease management in a systematic way to sustain sugarcane cultivation in the region and also to prevent buildup of disease epidemics.