Performing Department
Agriculture and Horticulture
Non Technical Summary
The peony (Paeonia spp), a flowering perennial plant, is one of two new, non-traditional agricultural crops in Alaska. The first peony farm was established in 1996. Establishing an agricultural industry in Alaska is very difficult and the peony cut-flower industry is no exception. In the past decade, diseases have become increasingly common. In a preliminary survey conducted recently, the PI learned that diseases, especially on some farms, are a serious threat to peony cut-flower production.Peonies, the tree and herbaceous species, are famed for their large, colorful and showy flowers. In the past decade, peonies of the herbaceous species attracted the attention of the cut-flower industry in the U.S. and the world. Growing market demand propelled peonies sales into a multi-million dollar industry. Because the flowering period of peonies is fairly short, with a limited shelf-life under current technology, to provide a continuous year-round supply of peonies requires tight coordination in production globally. Peonies are available from countries in the Northern Hemisphere (the Netherlands, Israel and the contiguous US states) from approximately mid-February through mid-July. Peonies from the Southern Hemisphere (New Zealand, Chile) are available from late-September through mid-January (Garfinkel, 2017). A production schedule gap--from mid-July through late-September--is left in the global supply chain. Because this is the time when Alaska peonies come to bloom (Holloway et al, 2005), the potential niche market and the reputed sale value of $10 per stem attracted many investors (some of whom had no previous experience in farming). Peony farms, many built on virgin soil, started by using rhizomes/root stocks imported primarily from the Netherlands. Presently, at $4 per stem, approximately 160 small peony farms are in production (down from 200), but the situation is decades away from market saturation (Auer, 2008).More than 25 Peony diseases were reported from the U.S. and the world, (Garfinkel and Chastagner, 2016). In a study on Botrytis and other peony diseases, Garfinkel found 6 species of Botrytis and S. sclerotiorum, Phoma spp and M. acerina. in Alaska (Garfinkel, 2017, Garfinkel and Chastagner, 2018). The recommended control for grey mold/Botrytis blight is frequent application of chemical fungicides. A few plants displaying the symptoms of tobacco rattle virus were found on one farm (Chastagner, 2018, personal communication). Tobacco rattle virus (TRV) is invasive to Alaska (McBeath, unpublished data). The pathway of introduction of TRV and other pathogens to Alaska needs to be investigated. Other diseases, such as those of crown and roots remain unknown. Growers frequently attribute the death of some peony plants to winter kill. However, results of the preliminary survey indicated that peony growers consider the most devastating disease to be bud blast. Because this disease is not well understood in Alaska environmental condition, and systematic research on the cause of the disease is much needed.Conventional agricultural practices that rely heavily on the use of chemicals could have especially serious consequences for the environment and human health in the far North. This is because of the persistence of pesticides in cold soils and subsequent bioaccumulation in plant tissues. To protect the ecosystem and human health, environmentally-responsible disease management measures for grey mold/Botrytis blight, bud blast and other diseases using biological and nutritional measures should be studied, and biological control and nutrient therapy practices should be developed.
Animal Health Component
0%
Research Effort Categories
Basic
100%
Applied
(N/A)
Developmental
(N/A)
Goals / Objectives
To discover, identify, and characterize microbes, biological control agents, biorational compounds, pathogen-suppressive microbiomes, as well as cultural practices and organic amendments that reduce plant diseases and damage caused by soilborne plant pathogens and improve plant health.
To determine how microbial populations function to suppress disease and how plants and the environment relate to this function.
Project Methods
This project will enlist the participation of peony farmers, who serve as "citizen scientists" are frontline observers of the project. The first alert sent by these citizen scientists will enable the PI to make rapid responses.Another applied research action is to use knowledge and commercially available products in disease control. Field testing of Plant Helper (formulated cold tolerant Trichoderma atroviride) and Copper phosphite and Copper-halo-phosphite, will yield information on the suppression of Botrytis blight/grey mold and other diseases, on improvement of nutrient uptake, and on enhancement of the quality and quantities of peony flower production, etc. (see Section 4.D.) To acquire accurate evaluation of efficacies of these products on peony plants, nutrients in the tissues of peony will be used as an indicator. Nutrient data of peony tissues, acquired using microwave assisted acid digestion and ICP-OES (Section 4.C.), will be evaluated along with traditional evaluation by visual observation.This is the first project to apply cutting edge technologies in the study of the interactions of plants (peony), diseases (grey mold/Botrytis blight, bud blast, white mold), microbial communities and agricultural practices in Alaska. Protocols used in this research are detailed in Section 4.E.The PI has more than 30 years experience in the isolation, identification, selection, fermentation, formulation and commercialization of biological control agents. It is highly likely that a large number of beneficial microorganisms will be produced in this project, through conventional methods and advanced technologies (see Section 4.D.). These beneficial microbes will be identified and characterized. These isolates displaying novel abilities will be evaluated for their commercialization potential.This is also the first project to combine nutrient therapy with biocontrols in the development of environmentally-responsible disease control strategies. The novel copper phosphate and copper-halo-phosphite, which is compatible with T. atroviride in tests conducted in the laboratory, has high mobility in plant tissues and theoretically should add additional benefits to disease control Biocontrol Agents.In the past, extensive efforts were made to isolate microorganisms at random from soil and plant material and then identify, through in vitro, greenhouse and field tests, those with potential as biological control agents or plant growth promoters. This strategy tended to yield candidate species that occur in high populations or those that grow quickly in culture. Past members of this project have producedBacillus(41) andTrichodermaproducts (19). With the development of high-throughput sequencing and microbiome studies, we can now implicate and identify new fungi and bacteria. But much of the community work is still correlative- certain OTUs are associated with a phenomenon, such as disease suppression. Few studies have isolated, identified and tested candidate organisms, i.e. performing Koch's postulates. Project researchers in WA and CA were among the first to do this (75, 8). The other limitation is that many of the bacteria and fungi that are implicated in a function have been isolated or cultured. This will require new methods of directed isolation. For example, genomic understanding of the organism may provide clues to specific catabolic processes and unique carbon and nitrogen sources that can only be used by the organism. Other novel techniques include the use of isolation chips (5), co-culturing, or manipulation of the environment eg. acid conditions, high CO2. Members will continue to search for novel biocontrol agents using more directed methods based on high-throughput sequencing. Members will share protocols, data pipelines, and develop common projects.However, little is known about how larger groups or consortia function in disease suppressiveness. One line of research has focused on making synthetic microbial consortia and testing them in model systems such as Arabidopsis. Core microbiomes are identified, and combinations are tested. However, because our group is more oriented to practical applications, we will focus on describing and characterizing entire microbiomes. To this end, some of our members (WA-ARS, KS-KSU) have begun to describe the core rhizosphere microbiome of wheat in disease suppressive soils, under long-term no-till (which can promote suppression). Network analysis has provided a powerful tool to see interactions that are not evident by just analyzing the abundance of OTUs. Members of WA-ARS have begun to use these tools in describing how herbicides such as glyphosate and fertilization may have subtle effects on microbial communities (52, 62, 63, 64).W-3147 members are on the cutting edge of soil and root microbiome research, which will provide a powerful tool for understanding how natural disease suppression occurs and give clues to cultural methods that can be used to enhance this under real grower conditions. One major advantage of investigating microorganisms associated with suppressive soils is that these organisms have demonstrated the ability to function in production agricultural systems. We can study both fungal and bacterial communities, and even nematode communities. This can lead to the development of more sustainable and effective strategies to manage soilborne pathogens and enhance soil health.Recent research has focused on how different cultivars may support a different root microbiome and thus enhance suppression of pathogens. But it also involves assessment of the impacts on soil health through microbiome research using high-throughput sequencing and also the impacts on the pathogen. This is done with recent advances in identification and quantification of pathogens and beneficials with real-time quantitative PCR, loop-mediated isothermal amplification, and smart chip based real time PCR (Wafergen). In other words, many of the findings in Objective 1 and 2 will be applied to this objective. Much of this research is conducted on grower fields and research stations, and thus involves interactions with growers as part of our extension effort (Objective 4, outlined in OUTREACH). Growers like to see demonstrations before they will adopt new technologies. Thus, the applied part is crucial. The successful completion of this objective will contribute to greater root health (reducing damage caused by soilborne pathogens), improving soil health and productivity, and reducing environmental risks; thus leading to a more sustainable and resilient agrosystem.