To overcome these problems,
there is a vital need to develop biocontrol agents which can survive
in acidic tea plantation soils. Earlier, Baby and Chandramouli
(1996) reported the in vitro antifungal activity of Trichoderma
and Gliocladium spp. against certain primary pathogens. In addition,
evaluation of these biocontrol agents under field condition
were performed against root diseases caused by Ustulina deusta
(Fr) Petrak and Botryodiplodia theobromae Pat (Borthakur and
Dutta, 1992). Similarly, biocontrol agents were evaluated against
grey blight disease of tea in the field (Sanjay et al., 2008).