Location: Northwest Irrigation and Soils Research
Project Number: 2054-21220-006-001-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Jul 1, 2023
End Date: Jun 30, 2024
Objective:
1. To demonstrate the impact of plasma treatment on wound healing, quality, and disease control for pink rot, silver scurf, and dry rot during storage.
2. To demonstrate the efficacy of plasma treatment for sprout control during post-harvest storage.
Approach:
Objective 1. Disease control, wound healing, and quality
Following harvest, potato tubers of ‘Clearwater Russet’ and ‘Russet Norkotah’ will be treated with a single dose of plasma (voltage: 4200 V) and various exposure times (10 mins, 20 mins, 30 mins, 40 mins) along with untreated control tubers. In addition, tubers will be artificially inoculated with Phytophthora erythroseptica (cause of pink rot), and Fusarium sambucinum (cause of dry rot), and naturally infected Russet Norkotah tubers with Helminthosporium solani (cause of silver scurf) and treated with plasma and evaluated for disease incidence and severity after 2 weeks (pink rot) and 3 months (dry rot and silver scurf). Wound healing will be evaluated according to the suberin and phenolic compounds deposition in periderm samples (3 replicates/treatment and 10 tubers/replicate) taken every 2 days up to 14 days after treatment using High-Performance Liquid Chromatography (HPLC). Physiological parameters, fresh weight loss, respiration, and reducing sugars measurements will be periodically performed to evaluate treatment effects. In-depth studies including microbiome and metabolite analyses (untargeted metabolomics) will be performed on tubers where specific plasma treatment resulted in disease reduction. Samples for microbiome analysis will be collected (5 replicates/treatment; 2 tubers/replicate) at ‘0’ time point (prior to plasma treatment), 1-, 2- and 14-days post-treatment along with plasma untreated control samples for each time point. Sequencing (16S and ITS barcode) will be performed to quantify changes in bacteria and fungi (both beneficial and pathogenic) respectively in response to the treatments to delineate their potential contribution in disease control during post-harvest storage. Untargeted metabolomics will be performed to evaluate global changes in metabolites in the tubers following plasma treatments in relation to their role in disease control during post-harvest storage. Metabolites related to antioxidant potential and wound healing of tubers such as phenols, flavonoids, suberin will be some of our specific interests besides other metabolites related to quality and nutrition.
Objective 2. Sprout control
Potato tubers of ‘Clearwater Russet’ and ‘Russet Norkotah’ will be treated with a single dose of plasma (voltage: 4200 V) and various exposure times (10 mins, 20 mins, 30 mins, 40 mins) immediately after harvest, prior to sprouting, and immediately after sprouting initiation. Tubers will be stored and periodically evaluated for sprout development (rating and sprout weight) and other physiological parameters such as weight loss and respiration. A total of 3 replicates and 10 tubers/replicate will be evaluated for the parameters. Untargeted metabolomics will be used to identify global changes in metabolites in the tubers where plasma treatment control sprouting (along with plasma untreated samples) during post-harvest storage.
