Skip to main content
ARS Home » Northeast Area » Frederick, Maryland » Foreign Disease-Weed Science Research » Research » Research Project #439284

Research Project: Discovery and Development of Microbial-Based Biological Control Agents for Use Against Invasive Weeds in the United States

Location: Foreign Disease-Weed Science Research

Project Number: 8044-22000-047-00-D
Project Type: In-House Appropriated

Start Date: Oct 1, 2020
End Date: Sep 30, 2025

Objective 1: Isolate, identify, and evaluate endemic plant pathogens that can be utilized as biological control agents of invasive weeds, such as swallow-wort, garlic mustard, and Japanese hop. [NP304, Component 1, Problem Statement 1C; Component 2, Problem Statement 2B] Sub-objective 1.A – Isolation and identification. Sub-objective 1.B – Evaluation of pathogen efficacy. Sub-objective 1.C – Evaluation of disease reaction among non-target and target species. Sub-objective 1.D – Develop and submit a proposal for release, and if approved, participate with cooperators in release and post-release monitoring of the pathogen(s). Objective 2: Determine the diversity and population dynamics of microbes associated with invasive weeds. [NP304, Component 1, Problem Statement 1C; Component 2, Problem Statements 2A and 2B] Sub-objective 2.A – Characterize the microbiome/virome of invasive weed species. Sub-objective 2.B – Evaluate the emergence of endemic phytopathogens on non-native, invasive weed species. Sub-objective 2.C – Develop accurate and rapid means for identification and detection of microbes permitted for field release. Objective 3: Develop innovative technologies to enhance or complement biological control agents and suppress weed health, such as RNA interference and encapsulation matrices. [NP304, Component 2, Problem Statement 2A] Sub-objective 3.A – Evaluate the efficacy and applicability of exogenous double-stranded RNA applications for plant health suppression. Sub-objective 3.B – Evaluate encapsulation matrices that support microbe survival and disease development.

Plant pathogens and plant-associated microorganisms will be collected from target invasive weeds in the U.S.A, and evaluated for their potential use as biological control agents using conventional, molecular, and technology driven approaches. The conventional approach is a cyclical method that identifies and evaluates promising candidate plant pathogens as biological control agents of invasive weeds. The molecular approach leverages advances in genomics to characterize and exploit weed microbiomes and viromes for insights into pathogen emergence and novel microbial candidates for host suppression. The technology driven approach will investigate technological advances to augment microbial-based biological control agents and to provide value-added synthetic properties to increase disease development under diverse environmental conditions. Microorganisms will be evaluated for the risk associated with intended release into ecosystems containing economically and ecologically important North American plant species. Risk will be evaluated based on disease reaction of species related to the target weed from a test-plant list reviewed and modified according to recommendations of regulators at the USDA Animal and Plant Health Inspection Service. Microorganisms determined to have an adequately narrow host range will be proposed for release in the U.S.A. Proposals for release of the microorganism will be developed for review by the Technical Advisory Group for Biological Control Agents of Weeds, and subsequent development of an Environmental Assessment, declaration of Finding of No Significant Impact and issuance of federal and state permits for release. Inoculum of the microorganism will be prepared in sufficient quantity for release, and target weeds will be inoculated in the field under conditions that favor disease development and establishment. Establishment and spread of microorganisms will be monitored in the field by recording disease symptoms on the target weed and re-isolating the microorganism. Damage to target weed populations and environmental factors important in microorganism establishment, efficacy and spread, will be measured.