PLANT MICROBE INTERACTIONS Identification of mVOCs from Andean Rhizobacteria and Field Evaluation of Bacterial and Mycorrhizal Inoculants on Growth of Potato in its Center of Origin Siva L. S. Velivelli & Peter Kromann & Paul Lojan & Mercy Rojas & Javier Franco & Juan Pablo Suarez & Barbara Doyle Prestwich Received: 19 April 2014 /Accepted: 8 October 2014 /Published online: 23 October 2014 # Springer Science+Business Media New York 2014 Abstract Food security (a pressing issue for all nations) faces a threat due to population growth, land availability for grow- ing crops, a changing climate (leading to increases in both abiotic and biotic stresses), heightened consumer awareness of the risks related to the use of agrichemicals, and also the reliance on depleting fossil fuel reserves for their production. Legislative changes in Europe mean that fewer agrichemicals will be available in the future for the control of crop pests and pathogens. The need for the implementation of a more sus- tainable agricultural system globally, incorporating an inte- grated approach to disease management, has never been more urgent. To that end, the Valorizing Andean Microbial Diversity (VALORAM) project ( http://valoram.ucc.ie), funded under FP7, examined the role of microbial communities in crop production and protection to improve the sustainability, food security, environmental protection, and productivity for rural Andean farmers. During this work, microbial volatile organic compounds (mVOCs) of 27 rhizobacterial isolates were identified using gas chromatography/mass spectrometry (GC/MS), and their anti- fungal activity against Rhizoctonia solani was determined in vitro and compared to the activity of a selection of pure volatile compounds. Five of these isolates, Pseudomonas palleroniana R43631, Bacillus sp. R47065, R47131, Paenibacillus sp. B3a R49541, and Bacillus simplex M3-4 R49538 trialled in the field in their respective countries of origin, i.e., Bolivia, Peru, and Ecuador, showed significant increase in the yield of potato. The strategy followed in the VALORAM project may offer a template for the future isola- tion and determination of putative biocontrol and plant growth-promoting agents, useful as part of a low-input inte- grated pest management system. Keywords mVOCs . Sustainability . Andean potato . Rhizobacteria . AMF . Biocontrol Introduction In the Central Andean Highlands of Peru, Bolivia and Ecuador—the center of origin of potatoes, where potato is the main food crop—most farmers use small amounts of organic manure and chemical fertilizer to improve crop S. L. S. Velivelli : B. D. Prestwich (*) School of Biological Earth and Environmental Sciences, University College Cork, Butler Building, Distillery Fields, North Mall, Cork, Ireland e-mail: b.doyle@ucc.ie S. L. S. Velivelli e-mail: s.velivelli@umail.ucc.ie P. Kromann International Potato Center (CIP), Panamericana Sur Km 1, Apartado, 17-21-1977 Quito, Ecuador e-mail: p.kromann@cgiar.org P. Lojan : J. P. Suarez Departamento de Ciencias Naturales, Universidad Técnica Particular de Loja (UTPL), San Cayetano Alto y Paris s/n, C.P. 11 01 608 Loja, Ecuador P. Lojan e-mail: pdlojan@utpl.edu.ec J. P. Suarez e-mail: jpsuarez@utpl.edu.ec M. Rojas International Potato Center (CIP), Av. La Molina 1895, Apartado, 1558 Lima, Peru e-mail: m.p.rojas@cgiar.org J. Franco Fundación PROINPA Foundation, Casilla Postal 4285Av. Meneces, Km 4, El Paso, Cochabamba, Bolivia e-mail: j.franco@proinpa.org Microb Ecol (2015) 69:652–667 DOI 10.1007/s00248-014-0514-2