Abundance of Beneficial Soil Microbes in the Rhizosphere of Coffee Plants Infected by Pratylenchus coffeae

Abstract

Enzymatic transformation in the Nitrogen (N) and phosphorus (P) cycles in soil can only be carried out by microbes. The latest approach in coffee cultivation is to utilize soil microbes to enhance plant growth, also to reduce the attack of the nematode Pratylenchus coffeae on coffee roots. This exploratory study aimed to observe the attack of P. coffeae on coffee tree, and the presence of N-fixing bacteria (NFB) and P-solubilizing microbes (PSM) in the coffee rhizosphere which have the potency to be used as biofertilizer and bioprotectants in coffee plantation. The study was conducted in Arabica and Robusta coffee plantation of PT Perkebunan Kalibendo, East Java; on immature plants (IP) and mature plants (MP). This exploration explained that the IP and MP of arabica and robusta coffee plantations were attacked by P. coffeae. The NFB and PSM were successfully isolated from the rhizosphere of both coffee plantations types. The population of NFB Azotobacter in IP was lower than in MP, but the PSM population in IP rhizosphere was not different from that in MP. Based on morphological and biochemical characterization, three isolates of Azotobacter bacteria, six species of P-solubilizing bacteria and six species of phosphate-solubilizing fungi were obtained. This exploration confirmed that the microbes involved in the N and P cycle colonized the rhizosphere of coffee which was attacked by P. coffeae. Further research is recommended to observe the effectiveness of microbes as biological fertilizers and bioprotectants for coffee plants.