Skip to main content
ARS Home » Research » Research Project #426041

Research Project: Improving the Quality of Grapes, Other Fruits, and their Products through Agricultural Management


2018 Annual Report

Objective 1: Identify, develop, and define analysis techniques to evaluate primary and secondary metabolites of fruit, fruit products, and wine. [NP 305; C1, PS1B] Sub-objective 1.A. Determine quality indicator metabolites and analytical methods for their analysis; evaluate and optimize new methods where insufficient data exists. Sub-objective 1.B. Deploy quality component measurements to optimize agricultural practices targeted at improving product quality. Objective 2: Integrate canopy- and fruit-specific management practices in grapes and berries to enhance crop productivity and fruit quality. [NP 305; C1, PS1B] Sub-objective 2.A. Determine development of fruit quality parameters as driven by the interaction between temperature and the timing of temperature anomalies during critical periods of fruit development. Sub-objective 2.B. Quantify standard industry pruning methods for grapevines and develop formal pruning standards necessary to achieve targeted goals for canopy structure; evaluate efficacy of manual pruning and algorithm-driven mechanical systems to achieve canopy structure goals. Sub-objective 2.C. Define canopy and fruit temperature thresholds leading to reduced fruit marketability in drip-irrigated blueberry fields. Objective 3: Develop cultural management strategies that mitigate the impact of abiotic stresses (drought and cold) in winegrapes. [NP 305; C1, PS1B] Sub-objective 3.A. Determine how irrigation spatial delivery, frequency, and amount affect the photosynthesis, water use efficiency, crop load and berry maturity of winegrapes. Sub-objective 3.B. Determine the influence of seasonal water deficit on cold acclimation during bud dormancy in winegrapes.

Project objectives will be accomplished by integrating research across three core disciplines: food chemistry- phytochemical analysis, plant-microclimate interactions, and crop physiology. A systematic approach in targeted fruit quality compound analysis to predict the magnitude by which climate and cultural factors impact fruit quality components will be used. This approach will allow us to improve and define analytical methods for plant metabolite analysis that advance our comprehension of the relationships among canopy management, canopy microclimate, water management, and vine cold hardiness and their effects on fruit development, fruit quality components, and vine physiology. If weather interferes with experimental treatments and sampling, experiments will be adjusted and extended an additional growing season.

Progress Report
This is the final report for project 2072-21000-047-00D, which terminates November 2018. Writing is underway for the next ARS project cycle. During the new project plan, ARS scientists will continue research that improves fruit quality through agricultural management techniques. During the past five years, selected chemical and field methods were employed for investigating the relationships between agricultural practices (e.g. cover cropping vs. tilling), abiotic stresses (e.g. salinity), biotic stresses (e.g. virus status), and genotypes/cultivars (e.g. ‘Pinot noir’ grapes) and their effect on fruit quality components important to agriculture or food systems. For the new project plan (2018-2023), ARS scientists in Parma, Idaho (worksite of Corvallis, Oregon) have proposed refinements to agricultural management, food production, and safety practices for use by growers, fruit processors, researchers, and consumers to improve fruit and fruit product quality, and that sustain U.S. agriculture’s economic position in a globally competitive marketplace. During the life of the project, ARS scientists made significant progress toward project objectives. Analytical method guidelines were developed for determining the phenolics (also known as natural compound, phytochemicals, secondary metabolite) of ingredients used in food/dietary supplements for authenticity, quality, and safety (Sub-objective 1A. Phenolics from new cultivars and genotypes of blackberry, red raspberry, black raspberry, and strawberry were thoroughly identified (Sub-objective 1B). Growing conditions (vineyard floor management by cover cropping and tilling, vine nutrition, canopy management, etc.) were evaluated for better understanding of food phenolics (Sub-objectives 1B and 2A). Adaptive cultural practices were developed for extreme weather ready wine grape production (plant hormone application, clay application, different irrigation strategies, etc.) (Sub-objective 3A). Finally, ARS scientists generated new knowledge about the long-term effects of drought on grapevine process and the ability to withstand severe winter conditions (cold acclimation) (Sub-objective 3B).

1. Blackberry dietary phenolics clarified. Blackberries have long been a popular small fruit, and the characteristic qualities associated with blackberries are closely linked to production of primary and secondary metabolites within the plant. Phenolics are secondary metabolites essential to plant biologic processes, and in blackberries they are crucial to many attributes of the fruit that are perceived as positive qualities, including appearance, taste, and storability. An ARS scientist in Parma, Idaho, assembled the chemical composition of blackberry fruit, clarifying to growers, processors, and consumers that blackberry quality components differ with cultivar/genotype and plant age, and they vary with environmental conditions, grower management practices, processing methods, and storage conditions. In addition to their phenolics, blackberries are also a source for many other dietary nutrients, including vitamin C, vitamin A, vitamin E, vitamin B6, folic acid, dietary fiber, potassium, phosphorous, magnesium, calcium, and iron.

2. Vineyard cover cropping influence on wine. Top quality Oregon ‘Pinot noir’ winegrape vineyards commonly reduce yield by cluster thinning, with the assumption that this practice produces grapes that make a higher quality wine. ARS scientists in Parma, Idaho, and Prosser, Washington, in collaboration with Oregon State University, determined relationships between crop load metrics and berry composition for ‘Pinot noir’ through the manipulation of vegetative growth (vine vigor) with competitive cover cropping of the vineyard floor (red fescue), and by controlling the fruit yield with cluster thinning. The use of floor management treatments (full grass, one alleyway flanking the vine row, or both alleyways flanking the vine row) altered both canopy size and yield, due to altered nitrogen status. Yield had the greatest influence on grape pH and total anthocyanin concentration during the coldest and highest production year, although wine sensory evaluations revealed no differences in quality for two of the three growing seasons’ wines. Cluster thinning to adjust yields may not alter source/sink relationships enough to overcome the ripening limitations of cool climates, which could limit its benefit to wine quality. Vineyard floor management and cluster thinning inconsistently affected ‘Pinot noir’ crop load, grape composition, and wine quality.

3. Drought stress in wine grape delays the onset of dormancy in autumn and reduces required chilling exposure for resumption of growth. Dormancy is a grapevine survival mechanism to avoid injury during exposure to low temperature. An ARS scientist in Parma, Idaho, in cooperation with an ARS scientist in Geneva, New York, and Cornell University collaborators, used a bud-forcing assay to monitor the dormancy transitions of field-grown ‘Malbec’ grapevines that were irrigated over seven consecutive growing seasons to supply 35, 70, or 100% of estimated water demand. Canes were field-sampled from deficit-irrigated and fully-watered plots at multiple time points over a span of 100 days, beginning 30 days prior to harvest. Drought stress shortened the dormancy cycle by delaying the autumn onset of dormancy, decreasing the amount of cold exposure required for release from dormancy and increasing the readiness to resume growth. Results support the idea that drought stress-induced regulatory networks ‘cross-talk’ with environmental and hormonal regulatory signals that modulate the activity-dormancy cycle. Understanding the underlying mechanisms by which drought stress alters the activity-dormancy cycle appears to be critical for sustaining vine productivity due to climate regime.

Review Publications
Bushakra, J., Dossett, M., Carter, K., Vining, K., Lee, J.C., Bryant, D., Vanburen, R., Lee, J., Mockler, T., Finn, C.E., Bassil, N.V. 2018. Characterization of aphid resistance loci in black raspberry (Rubus occidentalis L.). Molecular Breeding. 38:83.
Finn, C.E., Strik, B.C., Peterson, M.E., Yorgey, B.M., Moore, P., Jones, P.A., Lee, J., Martin, R.R. 2018. ‘Kokanee’ primocane-fruiting red raspberry. HortScience. 53(3):380–383.
Finn, C.E., Strik, B.C., Yorgey, B.M., Mackey, T.A., Moore, P., Dossett, M., Jones, P., Lee, J., Martin, R.R., Ivors, K., Jamieson, A. 2018. ‘Marys Peak’ strawberry. HortScience. 53(3):395–400.
Finn, C.E., Strik, B.C., Yorgey, B.M., Peterson, M.E., Jones, P.A., Lee, J., Martin, R.R. 2018. ‘Columbia Giant’ thornless trailing blackberry. HortScience. 53(2):251–255.
King, B.A., Shellie, K. 2018. Wine grape cultivar influence on the performance of models that predict the lower threshold canopy temperature of a water stress index. Computers and Electronics in Agriculture. 145:122-129.
Lee, J. 2017. Blackberry fruit quality components, composition, and potential health benefits. In: Hall, H.K., Funt, R.C., editors. Blackberries and Their Hybrids. Oxfordshire, United Kingdom: CABI. p. 49-62.
Reeve, A.L., Skinkis, P.A., Vance, A.J., McLaughlin, K.R., Tomasino, E., Lee, J., Tarara, J.M. 2018. Vineyard floor management and cluster thinning inconsistently affect ‘Pinot noir’ crop load, berry composition, and wine quality. HortScience. 53(3):318-328.
Shellie, K., Kovaleski, A., Londo, J.P. 2018. Water deficit severity during berry development alters timing of dormancy transitions in wine grape cultivar Malbec. Scientia Horticulturae. 232:226-230.