Location: Horticultural Crops Production and Genetic Improvement Research Unit
Project Number: 2072-21000-055-052-G
Project Type: Grant
Start Date: May 1, 2024
End Date: Oct 31, 2025
Objective:
1. Determine the effects of evaporative cooling on flower temperature, honey bee activity, pollination outcomes, and fruit quality.
2. Quantify the effects of different groundcover/mulching practices on canopy temperatures and associated risk of heat damage during extreme heat events.
3. Evaluate the impacts of commercially available biostimulants on pollen viability and pollination outcomes during extreme heat events.
4. Calculate the cost-benefits of evaporative cooling and biostimulant application as methods to mitigate against heat damage during the pollination period.
5. Extend project information to the blueberry industry.
Approach:
Two field experiments will be established to evaluate the effects of evaporative cooling (abbreviated as “cooling”) using microsprinklers or sprinklers. The first experiment will be conducted in a newly planted research field in OR with four cultivars, including ‘Duke’, ‘Draper’, ‘Cargo’, and ‘Aurora’. The second experiment will be conducted in a young field of ‘Aurora’ and a mature field of ‘Bluecrop’ in MI.
To quantify the effects of different groundcovers on canopy and flower temperatures, subplots of ‘Aurora’ located in the experimental field in OR will be split into sub-subplots of seven plants each and treated with sawdust, weed mat, or left bare.
Evaporative cooling requires significant infrastructural and management costs and is a new technology for many growers. Sprayable biostimulants that improve stress tolerance may provide a more economical approach to mitigating heat stress and do not require infrastructural investments. Several commercially available biostimulants have shown promise at inducing tolerance to extreme heat in raspberry plants. The most promising products will be compared to untreated plants when exposed to heat stress.
Cost and benefits of cooling and biostimulant application will be calculated using project data and blueberry enterprise budgets available for WA, OR, and MI.
Trade journal and scientific papers will be generated from the project to aid information dissemination.
