Enhanced Mycorrhiza-Helper Bacteria Inoculant for The Health of Arabica Coffee Seedlings Grown in Nematode-Infected Soil Reginawanti Hindersah (a*), Iis Nur Asyiah (b*), Widi Amaria (c), Betty Natalie Fitriatin (a), Imam Mudakir (b)
a) Department of Soil Science and Land Resources, Faculty of Agriculture, Universitas Padjadjaran, Jalan Ir. Soekarno Km. 21, Jatiangor, Sumedang 45363, Jawa Barat, Indonesia
b) Department of Biology, Faculty of Teaching and Education, Universitas Jember, Jl. Moch. Sruji No.64-60, Cangkring, Kec. Patrang, Kabupaten Jember, Jawa Timur 68111, Indonesia
c) Research Center for Horticultural and Estate Crops, National Research and Innovation Agency, Jl. Raya Jakarta - Bogor KM 46, Cibinong Jawa Barat 16911, Indonesia
Abstract
The Arbuscular mycorrhizae fungi (AMF) and mycorrhiza-helper bacteria (MHB) are sustainable ways to control the nematode Pratylenchus coffeae infection on coffee plantations- moreover, AMF facilitates phosphorus availability for plants. Developing an MHB inoculant is the key to reducing endoparasite attacks. The objective of the experiment was to 1) formulate an enhanced MHB liquid inoculant composed of Bacillus subtilis and Pseudomonas diminuta and 2) observe its effectivity in controlling P. coffeae in roots- and improving the P status in soil and plants, and the growth of Arabica coffee seedlings infested by the nematode. Enhancing MHB liquid inoculant was conducted in the small-scale reactor by optimizing the concentration of molasses, Nitrogen, Phosphorus (P), and the initial composition of both bacteria. A greenhouse experiment to test the effectivity of AM fungi of Glomus agregatum and MHB inoculant was set in a randomized block design with five treatments and five replications. The results demonstrated that the improved broth formulation for MHB liquid inoculant was composed of molasses 2%, NH4Cl 0.05 %, and KH2PO4 0.1 % with initial volume composition of B. subtilis and P. diminuta of 2:3. Scaling up MHB inoculant in 30-L reactor increased the bacterial population up to 1010 colony forming unit (CFU)/mL and P content up to 100 mg/kg. Inoculating coffee seedlings by 200 spores of G. agregatum and MHB of 109 CFU/mL increased leaf number, P uptake by plants, and soil P while decreasing root damage and nematode population in soil and roots. Mixed AMF and MHB decreased P. coffeae infestation in roots by 70.79% and increased P content in soil and plant by 57.2 % and 61.9 %, respectively.
