Responses of Potato (Solanum tuberosum) to Glomus sp. Combined with Pseudomonas diminuta at Different Rates of NPK Fertilizers

Abstract

Conventional farming for potato production in Indonesia has been using NPK fertilizer at high application rates. Any adverse environmental effects that might arise trough this fertilizer use shall be avoided. Application of bioferrtilizer consisted of ArbuscularMycorrhizal Fungi (Glomus sp.) isolated from the potato farming area and Mycorrhizal Helper Bacteria (Pseudomonas diminuta) have been tested to reduce the use of NPK rates in the production of potato crops. The inoculant has been pot-cultured prior to its application on potato crops. The controlled-field site experiment, used the mixtures of spores of Glomus sp. and inoculant of Pseudomonas diminuta, applied at different rates of NPK fertilizer. Results of the experiment showed that the application of Glomus sp. and Pseudomonas diminuta reduced the use of NPK up to 50%, where the growth, nutrients uptake(N,P,K), and tubers of potato had similar effect to the highest recommendation rate of NPK fertilizer (being applied by the farmers). Findings from this experiment confirmed the evidences that application of AM fungi and mycorrhizal helper bacteria could reduce the use of chemical fertilizer which support sustainable farming system. Further step has been done to scale up the production of inoculants for the wider use by local farmers. Keywords:Glomus, Pseudomonas, mycorrhiza, potato, NPK fertilizer.