Abstract

                                Chemical components like total chlorophyll, chlorophyll 'a' Chlorophyll 'b' reducing sugar, non reducing sugar and total sugar in relation to charcoal rot disease across three seasons were estimated and compared in each of the two proven resistant and susceptible sorghum cultivars. It was observed that the lower concentrations of total chlorophyll, chlorophyll 'b' and higher concentration of chlorophyll 'a', reducing sugar, non reducing sugar and total sugars were associated with resistance reaction to charcoal rot whereas the reverse trend was observed in the susceptible cultivars. The relative magnitude of concentrations of chlorophyll 'a', chlorophyll 'b' and total chlorophyll were higher during summer, whereas reducing sugar, non reducing sugar and total sugars were higher in Kharif for all the cultivars. It is further projected that the higher concentrations of chlorophyll 'a', reducing sugar, non reducing sugar and total sugars may be utilised as possible indices to screen sorghum genotypes against charcoal rot disease.

Key words : Charcoal rot