A New stalk rot disease of sugarcane caused byphaeocytostroma sacchari in india

abstract

An unusual stalk rot was noticed in sugarcane varieties at the Sugarcane Breeding Institute, Coimbatore, and in clones of sugarcane germplasm at the Sugarcane Breeding Institute Research Centre, Kannur, at maturity stage of the crop. Affected cane stalks showed straw coloured rind discolouration. Internally, orange-brown rotting was noticed at nodal regions, which extended further to internodal region emitting a distinctive sour odour. In some cases brownish discolouration throughout the infected canes was noticed. In severe cases, rotting of entire stalks and desiccation were observed. Blackish discolouration of the dried canes revealed numerous coiled thread like spore masses extruding from black pustules that break through the rind of the entire cane stalk. A survey for the intensity of the disease revealed that collections ofSaccharum spp. as well as hybrid clones were affected to the tune of trace to cent per cent infection. The pathogen cultured from the infected canes was identified asPhaeocytostroma sacchari (Ellis and Everh.) Sutton. Association of other fungi such asFusarium moniliformae,Varonaea botryosa andColletotrichum gloeosporioides was also found in certain infected samples. This is the first report of stalk rot disease caused byP. sacchari in India.