Efficacy of Systemic Fungicides Against Brown Root Rot (Fomeslamoensis) Disease of Tea (Camellia sinensis (L) O. Kuntze) in vitro and in Nursery Condition

The tea plant of commerce (Camellia sinensis (L) O. Kuntze) is grown in more than 50 countries lying between 43°N and 42°S latitudes and from sea level to 2300 m above mean sea level. These plants prefer warm humid climatic conditions, well-distributed rainfall and long sunshine hours. These conditions are also conducive for the growth of many pests and pathogens and further, the monoculture habitat provides a stable microclimate for their easy transmission and establishment. Brown root rot disease identified as the primary root disease of tea was isolated from naturally infected root of tea. The fungus is pathogenic to one year of tea plants, which exhibited brown root rot disease symptoms within one months of inoculation. Five systemic fungicides were screened and evaluated against the pathogen. Among the five fungicides used two namely, Propiconazole and Hexaconazole have shown 98.51 % and 100% inhibition properties against the pathogen at the concentration of 100mg/L, whereas Bavistin showed 12.58%, Roko 5.18 % and Ektino 1.48 % inhibition respectively. Therefore, the result of the present study suggest the potentials of use of Propiconazole and Hexaconazole at minimum concentration for maximum suppression inhibition of Fomeslamoensis. The results of the field observation have also been presented.