Behaviour of Soil Borne Inoculum of Colletotrichum falcatum in Causing Red Rot in Sugarcane Varieties with Varying Disease Resistance

Abstract

Red rot caused by Colletotrichum falcatum Went is a serious stalk disease affecting production and productivity in sugarcane. Soil borne inoculum of C. falcatum serves as the major source of primary inoculum in disease epidemics and critically plays a key role in disease cycle. However, information on infectivity of the soil borne fungal inoculum on sugarcane varieties varying in disease resistance, sett germination and disease development is lacking. We have taken up detailed studies on the impact of this inoculum multiplied on sorghum grains on infection of planted setts on a set of 10 sugarcane varieties varying in disease resistance and disease build-up in the field with 11 different pathogenic isolates varying in their virulence. This study suggested a differential behaviour of soil borne inoculum of C. falcatum on vulnerability of sprouting buds, and probably, this primary infection may lead to C. falcatum adaptation in new host varieties.