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ARS Home » Northeast Area » Kearneysville, West Virginia » Appalachian Fruit Research Laboratory » Innovative Fruit Production, Improvement, and Protection » Research » Publications at this Location » Publication #417807
Research Project: Integrated Production and Automation Systems for Temperate Fruit Crops

Location: Innovative Fruit Production, Improvement, and Protection

Title: Pillar tree architecture increases canopy light interception and impacts fruit quality in European plum

Author
item Tang, Lisa
item FARCUH, MACARENA - University Of Maryland
item Dardick, Christopher

Submitted to: Journal of Horticultural Science and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/20/2025
Publication Date: 2/7/2025
Citation: Tang, L., Farcuh, M., Dardick, C.D. 2025. Pillar tree architecture increases canopy light interception and impacts fruit quality in European plum. Journal of Horticultural Science and Biotechnology. https://doi.org/10.1080/14620316.2025.2458100.
DOI: https://doi.org/10.1080/14620316.2025.2458100

Interpretive Summary: In this study, we evaluated the effects of pillar tree architecture on canopy light environment and fruit quality in plum. Compared to the standard-shaped trees of the same parental cultivar background, canopy light availability was improved in trees exhibiting pillar architectures. As a result, the red color on the fruit skin was more intense and uniform for pillar trees than standard plum. Our results suggest that pillar architecture naturally increases sunlight exposure for fruit on the tree, which enhances skin red overcolor development and overall fruit appearance; thereby, reducing the pruning cost.

Technical Abstract: Previous studies demonstrated silencing TILLER ANGLE CONTROL 1 (TAC1), a gene promoting outward shoot growth, via RNA interference (RNAi), caused upright branch orientations and pillar architectures in nonbearing ‘President’ plum. To evaluate the impact of the pillar trait on mature tree growth, canopy light environment, and fruit quality, we compared bearing trees of two RNAi lines with reduced TAC1 expression to the untransformed control sharing the same parental background over two years. The upright shoot growth habits and pillar tree shapes persisted in nine-year-old plum of RNAi lines five years following the first report. Canopy light interception of pillar trees was two-fold greater than that of control. Between the RNAi lines, the consistent differences in fruit firmness suggest potentially different ripening rates but within the range of variation expected for plum. Fruit of pillar trees did not exhibit increases in size or soluble solids compared to controls; however, skin hues were more uniform and closer to red, indicating enhanced overcolour development. Our results suggest that upright shoot growth in plum allows improved light interception and may lead to enhanced fruit colouration, which can greatly reduce the need for intensive pruning and thereby, minimise the associated labour and cost while boosting fruit marketability.