Location: Horticultural Crops Production and Genetic Improvement Research Unit
2025 Annual Report
Objectives
This project’s overall goal is to refine agricultural management practices that growers use to improve fruit and fruit product quality.
Objective 1: Determine the impacts of variety selection and production management practices on fruit and product quality components to optimize practices for superior fruit and wine production. [NP 305, Component 1, Problem Statement 1B]
Subobjective 1A: Determine primary and secondary metabolites and their targeted analyses; evaluate and optimize analytical methods where insufficient data exists.
Subobjective 1B: Evaluate developed quality component measurements on new or improved fruit and fruit products, and link to agricultural management.
Objective 2: postponed until vacancy is filled.
Objective 3: Enhance management practices for small fruit production systems by optimizing soil health, weed suppression, and the interplay between plants and ecosystem dynamics for desired outcomes.
Approach
Project objectives will be accomplished by integrating research across three core disciplines: food chemistry/phytochemical analysis, crop physiology, and plant breeding. A systematic approach, with targeted analyses of fruit quality compounds, will be utilized to predict the magnitude that environmental factors and cultural practices impart to fruit quality. This strategy will allow us to improve and define analytical methods for plant metabolite analyses that advance our comprehension of the interactions between canopy management, vine nutrient treatments, water regimes, vineyard microbiome, vine virus status, and cultivar/genotype selections have upon fruit development, fruit quality components, and vine physiology. An additional growing season will be employed, if necessary, to account for interruptions during the experimental treatment or sampling schedules.
Progress Report
This is the final report for project 2072-21000-057-000D, “Improved Fruit, Grape and Wine Products through Precision Agriculture and Quality Component Evaluation,” which was replaced by new project 2072-30500-001-000D, “Resilient Production Strategies for Improved Small Fruit Quality.” For additional information, please see the new project report.
During the previous five years, selected chemical and field methods were employed to identify and refine agricultural management practices that growers use to improve fruit and fruit product quality. For the new project plan (2025-2030), ARS scientists in Prosser, Washington (worksite of Corvallis, Oregon), proposed to integrate soil science, crop physiology, and food chemistry to identify and refine agricultural management practices that growers can use to improve production and fruit product quality and sustain the economic competitiveness of United States agriculture.
In support of Objective 1, work was conducted that contributed to the release of three new blackberry cultivars with lower anthocyanin (red pigment) levels than standard commercial cultivars. Research was conducted to find a much-needed commercial replacement cultivar for black raspberry with greater disease resistance, high yield, and high anthocyanin levels. Perceived sweetness, acidity, and pigment of the fruit were linked to plant traits, and their associated genes is in progress. This work highlights the actual empirical data on black raspberry sugar composition and should help repudiate the misconception that Rubus fruit are high in sugar alcohols, which are associated with discomfort following consumption of large quantities of the fruit.
In grapes, research was conducted on how vintage, growing region, climate, vineyard management, biotic/abiotic stressors, and microbiome alter components important for healthy fermentation and wine quality. ARS researchers examined how vine nutrient status, vine virus status, and grape juice must/microbiome (independently) influence wine grape quality. Ongoing phenolic analyses were conducted on samples obtained from the deficit vine nutrient project. While some grapevine viruses are detrimental to grapevine health, crop load ratio, fruit characteristics, and ultimately to wine quality, others caused only minor issues. It is important to identify how specific grape vine viruses impact grape quality. Vine virus identification in commercial Idaho vineyards was the first step towards constructing virus diagnostic tools, tailored to the growing area, that can be used to mitigate future losses from vine infections. Grapevine red blotch virus was identified in Idaho commercial vineyards for the first time. Research on how specific vine viruses, like Grapevine red blotch virus, influence healthy fermentation and quality components for three growing seasons was completed in cooperation with commercial collaborators. Research on grape juice must/microbiome compositions were examined for the same winegrape clone from 15 vineyard sites for two vintages and linked to basic fruit quality measurements. Results from this data will allow growers to make informed decisions regarding vine rouging (the current method to address Grapevine red blotch virus) without decreasing grape quality or increasing production costs. In addition, the results provide a better understanding of grape microbiome diversity.
Additional research was conducted to help winemakers who are interested in new ways to enhance consumer wine experience and give their products a marketplace edge. Non-Saccharomyces yeasts (yeasts not traditionally used for alcoholic fermentation) were explored for alcoholic fermentation to discern if better tasting red and white wines could be made with lower alcohol content when compared to traditional yeasts (S. cerevisiae). The non-Saccharomyces yeast strains were chosen for their ability to produce the enzyme pectinase, which can break down pectin to improve mouthfeel in wine. Experimental wines were tested with and without pectin in young wines and after bottle storage.
Research on Objective 2 is postponed until the vacant position is filled.
In support of Objective 3, soil health challenges faced by wine grape growers in the viticultural regions of Washington and Oregon were evaluated. Soil samples from more than 40 grower-identified “problematic” soils were collected and analyzed for pH, nutrients, salts, and organic matter. These results were shared with growers, and soil samples from these vineyards were used to initiate several research projects focused on the role of soil properties on root-knot nematode colonization of plant roots. To further the basic research aspects of Objective 3, a project to study particulate organic matter in soils was proposed by ARS scientists and funded by the Pacific Northwest National Laboratory. As part of this collaboration, progress was made in developing a workflow to apply deep learning tools, like those used by self-driving cars to navigate, for the automatic detection and quantification of particulate organic matter in soils. This workflow can be applied to any image data set, allowing for the identification and quantification of complex features in images. This code was further adapted to count hops, grape leaves, wheat stems, and cranberries while simultaneously extracting information like area, perimeter, longest axis length, shortest axis length, and color from each individual hop, leaf, stem, or berry in the image. These tools can help researchers and growers automate the tedious task of measuring plant growth properties when trying to quantify the influence of soil-health-improving practices on plant growth. Additionally, a phosphorus (P) fertilization trial was initiated to help develop better models for understanding P availability in alkaline soils like those found in eastern Washington. Finally, funding was secured by the ARS scientist in Prosser, Washington, to establish a vineyard to study the long-term effects of vineyard management practices on soil health indicators. The vineyard was established and will be used for work proposed in new project 2072-30500-001-000D.
Accomplishments
1. Computers trained to spot water stress in young walnut trees. Water stress is particularly problematic for young trees which can die easily without sufficient water; early detection of water stress is crucial for preventing tree loss. ARS researchers in Davis, California, and Prosser, Washington, in collaboration with researchers at the University of California, Davis, trained a computer model using images of young walnut trees paired with corresponding conventional water stress measurements to visually identify water stress in walnut trees. This technology is a valuable starting point for building computer vision tools to identify drought stress in crops with a degree of sensitivity similar to more established by labor-intensive methods.
Review Publications
Potter, R.I., Lee, J., Ross, C.F. 2025. Early oxidation detection in white wine by electronic tongue: A preliminary study. Journal of Food Science and Nutrition. 13(6). Article e70366. https://doi.org/10.1002/fsn3.70366.
Margenot, A., Rippner, D.A., Green, P.G., Scow, K.M., Parikh, S.M. 2024. Counterion selection for ion controls of CuO-nanoparticles is important for assessing soil biological responses. Soil & Environmental Health. 2(3). Article 100094. https://doi.org/10.1016/j.seh.2024.100094.