Clemson University

Awards Issued Prior to January 20, 2025, Were Funded Under Previous Administrations and May Not Reflect the Priorities and Policies of the Current Administration. Stone Fruit and Nut Crops (peach, Almond, and Cherry) Provide Vital Contributions to Human Health, Communities, and Economies Across the U.s. These Crops Are Under Serious Threat of Rapid Collapse and Eventual Extinction Due to a Devastating Fungal Threat Called Armillaria Root Rot (arr). Arr Presents a Major Challenge to the U.s. Stone Fruit and Nut Industry. Growers With Arr - Infected Orchards Are Faced With a Persistent Problem, as Both the Host and the Disease Are Long-lived. Producers Cannot Rotate to Other Sites Due to the Lack of Un-infected Land for New Plantings, Especially Critical in SC Peach and Mi Cherry Industries. They Cannot Fumigate the Soil, and Once an Entire Orchard Is Replanted, They Are Left With the Prospects of Having to Replant Again Not Long After Having Invested in the High Orchard Establishment Costs. With This Same Scenario in Peaches in the Southeast, Cherries in Michigan, and Peach, Cherry, and Almond in California, Arr Is a Threat of National Importance. Without Practices to Eradicate the Pathogens or Methods to Counteract Reduced Productivity, Infected Sites Are Unsuitable for Replanting. the Pathogen Is Long-lived, With Inoculum That Can Persist Below Ground for Many Years. as Such, Leaving the Ground Fallow Before Replanting Would Require Up to a Decade and Have an Unacceptable Economic Burden on Producers. Furthermore, Planting Another Horticultural Crop Other Than a Prunus Species Is Not an Economically Viable Option, Given the Broad Host Range of Arr (500+ Woody Plant Species). Without Solutions, This Loss of Production Will Not Only Have Devastating Impacts on the Affected Producers and Rural Communities But Will Also Contribute to a Reduction in the Supply of These Products and Potentially Increased Costs for Consumers.u.s. Stakeholders and Industries That Span These Crops Have Given Arr the Highest Priority for the Development of Short and Long-term Solutions to Preserving These Critical Crops and Industries. the Most Sustainable and Effective Approach to Mitigate the Arr Threat to Peach, Cherry, and Almond Production in the U.s. Is to Develop Genetically Durable Arr-resistant Rootstocks. While Long-term Solutions Are Required, in the Interim, Short- and Medium-termed Solutions Are Necessary, Which Is Why This Project Encompasses Both. This Project Will Identify Resistant Germplasm, Characterize the Mode of Resistance and Understand the Genetic Base of the Resistance by Linking the Genome With Phenome Through Systems-scale Datasets, Such as Transcriptomics, Metabolomics, Etc., Along With Sophisticated Statistical Methods, to Enable Genomic Solutions and Translational Breeding of Natural (local and Exotic) Sources of Arr Resistance to Deliver Arr Resistant Rootstocks in the Longer Term. the Industry Will Perceive an Immediate Benefit With the Change in Cultural Practice and Direct Utilization of New Sources of Resistance in Nurseries. Above Ground Root Collar Excavation Cultural Practice (agrce), That Extends the Lifespan of Orchards on Arr Infected Sites, and Nursery and Producer Evaluation of Horticultural Acceptance of the Resistant Material, Provide Short- and Medium-term Solutions, Respectively, as the Work on Genetic Resistance Progresses. Cultural Practices Have the Potential to Reduce the Financial Burden of Arr to Producers by Extending the Long-term Productivity of Prunus Orchards, Therefore This Project Will Implement Agrce for Peach and Cherry and Explore the Use of Sectoral Chimera Rootstocks in Almond as a Strategy to Increase Tree Longevity Until Arr Resistant Compatible Rootstocks Are Developed. Socio-economic Research Will Determine Economic Effects of Arr and Impact of Proposed Solutions to Provide Guidelines for Growers, While Outreach and Extension Activities Will Target Peach, Cherry, and Almond Growers Affected by Arr and Tree-fruit Nurseries, as the Key Partners in Delivering Genetic Solutions to Producers, So That New Knowledge Can Be Quickly Disseminated and Feedback Obtained. in This Way, a Range of Consumers Will Benefit From Sustainable Stone Fruit and Nut Production, Which Would Increase Consumption and Improve Human Health and Physical Well-being.