Effect of consortia of potassium solubilizing bacteria and fungi on growth, nutrient uptake and yield of banana

Abstract

In the present study, three potassium solubilizing bacteria (KSB) Pseudomonas sp. (KSB 49, 239.75 mgl-1; KSB 43, 228.25 mgl-1 and KSB 47, 205.75 mgl-1) and three potassium solubilizing fungi (KSF) Aspergillus sp. (KSF 3, 334.66 mgl-1; KSF 13, 310.16 mgl-1 and KSF 31, 297.66 mgl-1) were found to be efficient to release potassium from mica as compared with the commercial potassium solubilizing bacterial (CKSB) strain Frateuria aurantia (CKSB1, 221.25 mgl-1). Based on the compatibility test, the consortia of efficient potassium solubilizers were designed separately. The liquid bio-formulation for KSB consortium and talc powder for KSF consortium was found to be effective delivery system in banana field. For their influence on growth, nutrient uptake and yield of banana under field conditions with 13 treatments including KSB and KSF consortia with the application of graded levels of K2O (50, 75 and 100% RDF). The fungal consortium + 75% K2O treatment showed higher potential followed by bacterial consortium + 75% K2O treatment. The application of KSF consortium along with 75% K2O (T6) recorded the highest marketable number of hands per bunch, fingers per hand, bunch weight and total yield (9.22, 16.22, 28.55 kg and 126.87 t/ha, respectively). The maximum total potassium uptake of 1198.17 kg/ha was recorded by KSF consortium + 75% K2O (T6), which was at par with KSB consortium + 75% K2O (T3) (1177.21 kg/ ha). These findings clearly indicated that addition of KSF and KSB in the nutrient schedule, 25% savings of the potassium fertilizers, i.e., 222.22 K2O kg/ha was possible.