Microbial inoculants to support tea industry in India

A long term study has been carried out for over a decade across various tea gardens, located in different parts of Indian Himalayan Region (IHR), with a focus on rhizosphere microbiology of tea. Occurrence of ‘negative rhizosphere effect’ exerted by the established tea bushes, in contrast to the normal stimulatory effect exhibited by the plants in general as well as young tea bushes, is the first and foremost feature associated with tea plants. Colonization by large populations of antagonists and lowering of the soil pH are the other important characteristics associated with tea rhizosphere. With a view of scaling down the use of chemical fertilizers, experiments were conducted on isolation, characterization and formulation of suitable microbial inoculants for use in tea plantations across hilly regions. Based on a number of attributes related to plant growth promotion and disease control, selected bacterial and mycorrhizal species have been developed in suitable formulations for application in tea plantations. The post-application observations indicated the benefits of microbial inoculations on seed, cutting and tissue culture raised tea plants. The present paper is an attempt to review the basic and applied research work carried out on rhizosphere microbiology of tea, particularly in the last two decades, with reference to possible application in the tea industry.