Location: Physiology and Pathology of Tree Fruits Research
Project Number: 2094-21220-003-016-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Sep 1, 2024
End Date: Aug 31, 2025
Objective:
1. Improve the tolerance of both scion and rootstock of apple and pear to low temperature stress during acclimation, dormancy and de-acclimation (All Institutions).
Hypothesis: Parameterization of cold hardiness and dormancy-related traits for current and future cultivars will improve risk models, increase grower confidence in adopting loss mitigation strategies, and provide a platform for the selection of cold-weather resilient cultivars in the future.
2. Reduce the negative impact of high temperature stress during summer/fall on fruit quality in apple and pear (WA, NY, OR).
Hypothesis: Quantifying the variability in susceptibility to sunburn, red color development, and maturity timing among current and future cultivars will support the selection of the most suitable cultivars and mitigation strategies for each region and will reduce losses from high summer temperatures in all production regions.
3. Model the economic impacts and risks of temperature extremes for decision making by commercial apple and pear producers.
Hypothesis: Economic models that quantify the effect of annual weather conditions on productivity and profitability, combines with tools that determine the economic impact of climate change on future fruit production will inform risk management strategies and crop insurance products for apple and pear production.
4. Initiate rapid and effective extension efforts on temperature-resilient management practices to mitigate the effect of adverse temperatures and climate change on pome fruit production.
Hypothesis: the development of a national Extension program for this project will result in more efficient transfer of knowledge and a better prepared industry to mitigate losses from extreme temperature events.
Approach:
Phenotyping approaches will be developed using current scion and rootstock cultivars for both apple and pear as well as segregating breeding populations for these traits. Advanced molecular and physiological methods will be used to characterize physiological changes occurring in late fall, winter, and early spring to identify genetic or biological markers associated with those traits. Regional, gridded models will be created to predict the current and future frequency of adverse winter events that can be incorporated into grower decision tools to assess risk of loss and make economical mitigation choices for their production system. A combination of controlled physiological experiments on current cultivars and phenotyping studies on breeding populations that segregate for high temperature-related traits will be conducted. These experiments will better characterize key physiological differences among cultivars with contrasting susceptibility to heat-related stresses and identify genetic markers that will enhance breeding efficiency for heat tolerant cultivars with high fruit quality. Similar to Objective 1, models will be developed to identify economic and geographic risk of adverse summer events that contribute to losses in fruit quality. The economic analysis will evaluate the costs and benefits associated with producing and marketing apples and pears under different climate scenarios. This research will focus on the impacts to crop yields, crop prices, and inputs across a range of cultivars, rootstocks, management techniques, and geographical areas. We will conduct a backward-looking exercise that will examine the effect of historical climatic events on yields, fruit quality, costs of production, and revenues for specific cultivars across major apple producing regions. Secondly, we will conduct a forward-looking examination of apple and pear markets in the United States given a range of potential climate scenarios in the future. Here, we will consider a series of projections about climatic conditions between 2022 and 2052 to simulate yields, prices, operating costs, and revenues for orchard owners for selected cultivars.
