Tea root brown-rot fungus disease reduction and yield recovery with rhizobacteria inoculation in both nursery and field trials

Bacillus cereus PM 43, Pseudomonas aeruginosa PM 105 and Pseudomonas species PM 112 enhanced plant growth besides induced suppression of brown root rot disease caused by Fomes lamoensis in tea plants under nursery and field condition. The experiment were done Completely Randomized Design (CRD) had three set of replication with ten plants in each and the experiments were repeated thrice for recording the data. From the nursery experiment it was revealed that tea saplings (clone TV 1) treated with pathogen and bacterial strain together resulted an enhanced survival of plants as compared to pathogen alone treated plants. On the other hand tea plants treated with bacterial strains alone, enhanced number of new leaves with more chlorophyll, number of lateral branches, shoot height, root length, fresh and dry weight were recorded. The activity of defense related enzymes such as L-phenylalanine ammonia lyase (PAL), peroxidase (POD), polyphenol oxidase (PPO) and total phenol were noted higher in plants treated with bacterial strain grown in pathogen infested soil. The findings revealed that the presence of the bacterial strains were able to reduce the disease severity of the pathogen to a significant level under nursery condition. In field trials, an enhanced percentage of the survival of the plants besides improved yield productivity in pathogen infested area. The findings hold a promise to use these strains for growth and yield promotion in tea besides suppression of agriculturally important diseases like brown root rot after successful large scale field trials.