Plant Volatiles-based Insect Pest Management in Organic Farming

Abstract Organic agriculture is increasing in popularity worldwide due to the rapidly growing market for organic products. In organic production, insects present a major pest challenge that negatively impacts crop health and yield. To successfully manage an organic farmland, an effective insect pest management program is key. In this review, we first describe the approaches currently used for pest management in organic farming. Next, we review natural plant defense mechanisms, especially those based on plant volatile organic compounds. Chemically complex, plant volatiles have multiple ecological roles in plant-insect interactions including attracting pollinators, acting as cues for foraging herbivores as well as functioning as direct defense, indirect defense, or interplant priming. Based on the ecological roles of plant volatiles, we then discuss in-depth how pest management may be improved through a variety of strategies including using resistant cultivars, polyculture, using beneficial microorganisms such as mycorrhizal fungi and endophytes, and using plant-derived pesticides, all of which are reviewed in the context of plant volatiles. Lastly, integration of these different strategies based on the trait of plant volatiles for a successful and sustainable pest management program in organic farming is discussed. Keywords: organic farminginsect pestsplant volatilesplant defenses ACKNOWLEDGMENTS We thank Dr. William Klingeman for critical reading of the manuscript. Research on plant metabolism and plant-insect interactions in F Chen's lab is supported by the USDA-ARS, the University of Tennessee Experimental Station, the Southeastern Sun Grant Center and the DOE Office Biological and Environmental Research (BER) - Genome to Life Program through the BioEnergy Science Center (BESC). Organic research in A. Wszelaki's lab is supported by the IR-4 Biopesticide Program, the Tennessee Department of Agriculture and the University of Tennessee Cooperative Extension Service. D. Panthee's lab is supported by North Carolina Tomato Growers' Association.