In this project, I propose to develop transfer methods of tomato foliar microbial communities effective at suppressing either bacterial spot or speck. I hypothesize that a community of microorganisms will provide increased plant health and prevent disease development to a greater extent than a single organism application, and that these microbes can be efficiently and economically transferred with dry plant material.
The specific objectives of this proposal are:
1. Develop a method for transferring communities via leaf application during germination in the greenhouse. Expected outcome: This objective will identify the efficacy of foliar microbial community transfer using plant material.
2. Determine the amount of plant material required for detectable disease suppression. Expected outcome: This objective will establish the amount of plant material needed for disease suppression to inform the economic feasibility of each transfer method.
3. Assess the efficacy of plant material that is stored over an extended period of time for disease reduction. Expected outcome: This objective will indicate whether plant material can be stored long-term prior to application and still retain effectiveness.
Overall, this project will provide a method for designing a more sustainable crop system for protecting crops from diseases in the short-term, and potentially long-term in the field. This research will provide the critical data that will aid in selecting methods that could be incorporated into current growing practices in an economically feasible manner.
Tomato is an economically important horticultural crop in the Northeast (MD, PA, NJ, NY), particularly for small-scale growers, with approximately 8000 acres harvested in 2017 worth $59 million (USDA-AMS 2017). Yet, bacterial diseases of tomato, such as bacterial speck (Pseudomonas syringae pv. tomato) and spot (Xanthomonas spp.), are becoming more prominent in the Northeast region, and in particular Pennsylvania, due to shorter crop rotations and increased rainfall (Bogash 2016). Given the nature of bacterial plant diseases and the economic necessity of growing highly susceptible cultivars, there is significant reliance on chemical (e.g. fixed copper) and antibiotic (e.g. streptomycin) control measures (Vidaver 2002). However, such control management strategies have become less effective as resistance has emerged and spread through pathogen populations (Stall and Thayer 1962; Stall, Loschke, and Jones 1986; Obradovic et al. 2004). Hence, alternative approaches, such as utilizing biological control agents (BCAs), have the potential to substitute or combine with currently employed strategies to provide more robust disease control in both conventional and organic tomato production.
Preliminary research was conducted in the summer of 2019 (supported by Pennsylvania Vegetable Growers Association) to identify suppressive foliar microbial communities that displayed enhanced disease suppression. Additionally, different plant material transfer methods were trialed. The analysis of the microbial communities is on-going. The suppressive foliar microbial communities from this work will be the benchmark for this proposal.
Experiments will be conducted in the coming months in a growth chamber environment to test the protocols for each of the transfer treatment methods.
Results are not available.
Education & Outreach Activities and Participation Summary
Currently, no educational or outreach events have been undertaken.
No project outcomes at this stage.
We have identified that a microbial community-based approach could improve plant productivity due to increased pathogen suppression and this approach is supported by previous theoretical and empirical research. This management strategy will support sustainable IPM systems and be applicable in conventional and organic tomato production.