Abstract

A field experiment was conducted to study the efficacy of indigenous potassium solubilizing bacteria (KSB) in combination with various dosages of potash fertilizers along with recommended dose of nitrogen (N) and phosphorus (P) fertilizers in tea plants. Soil and leaf samples were drawn from the respective plots and they were subjected for the analysis of various parameters related to nutrients and quality aspects. Among various treatments, plants treated with N₁₀₀ P₁₀₀ K₇₅ + KSB concentration formulation was found to be the best in terms of high chlorophyll, carotenoid, N, P and K contents in the crop shoots followed by other treatments. Significantly higher yield of the green leaf was achieved by the same treatment. K content in soil and also in crop shoots was greatly improved due to the application of KSB along with possible reduced doses of potash source. On the other hand, N₁₀₀ P₁₀₀ K₂₅ + KSB formulation and untreated control plots have exhibited least green leaf yield and nutrient status of soil and crop shoots. The biochemical parameters, total polyphenols, catechins, amino acids and sugars were significantly at higher level in plants after imposing treatments in combination with KSB. Biometric parameters such as plucking surface of the tea bush canopy, plucking points per unit area, internodal length, leaf moisture and dry matter contents were analyzed and found to be high in tea plants treated with N₁₀₀ P₁₀₀ K₇₅ + KSB combination. Banji content was significantly reduced invariably in all the treatments except the untreated control plots. Evaluation of KSB population in soil revealed thatwherever KSB was incorporated, there was a significant increase in population level and has coincided with dehydrogenase enzyme activity. The flush shoots of tea comprising of three leaves and a bud were subjected to manufacture black tea, and it was revealed that almost all the tea quality parameters such as theaflavin, thearubigin, highly polymerized substances, total liquor colour, caffeine, briskness, colour and flavour indexes were greatly improved in KSB treated plants, which in turn improve the quality as well. This finding confirms that the influence of indigenous potassium solubilizing bacteria upon potassium nutrient exhibited improvement in the productivity and nutrient uptake in plants and retained in soil including quality parameters in tea plantations.

Key words: Tea, potassium solubilizing bacteria, biofertilizer, nutrient status, crop productivity, tea quality.