Location: Subtropical Plant Pathology Research
Project Number: 6034-22000-042-007-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Apr 24, 2015
End Date: Aug 31, 2019
Objective:
Test a commercial-scale heat treatment protocol for eradicating pathogens on contaminated or infected strawberry nursery stock.
Approach:
All heat treatment trials will be conducted at Lassen Canyon Nursery’s high elevation plantings. Three treatments will be evaluated using three cultivars Ventana (sensitive to heat damage), Festival (tolerant to heat treatment), and Sweet Anne (locally popular variety) and will include blocks of plants subjected to: (i) Standard heat treatment with no additional chemical inputs for disease management, (ii) Standard heat treatment with additional chemical inputs for disease management, (iii) Standard planting (no heat treatment) managed with standard grower practices. The “standard” heat treatment protocol consists of a 1 hour pre-treatment at 37 C, followed by a 1 hour cool-down period, then exposure to 44 C for 4 h for the final heat treatment. For each cultivar, treatments will be allocated to 1/3-acre blocks. Treatments will be arranged in a split-plot design with heat-treatment procedure being designated as the whole-plot treatment, and variety as the subplot treatment. The experiments will be repeated once. All nutrient, insect management practices, and disease management practices (including rouging of diseased plants) will be at the discretion of the nursery – w/ the exception of treatment (i) where no additional disease management practices will be employed.
Plots will be rated weekly for the first six weeks after planting to assess growth and disease development. After that, plots will be rated every two weeks to measure disease development. Plots will be harvest according to standard practices and plant yield will assessed. Each dependent variable will be analyzed as generalized linear model independently for data collected at the nurseries and fruit production fields. Analysis of ALS in nursery production fields is a straightforward RCB design. Analysis of ALS in fruit production fields will account for both grower variability and nursery variability.
