Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/13/2025
Publication Date: 3/9/2025
Citation: Lawrence, B.T., Fazio, G., Gonzalez-Nieto, L., Robinson, T. 2025. Rootstock effect on horticultural performance and fruit quality is not uniform across five commercial apple cultivars in western New York. Frontiers in Plant Science. https://doi.org/10.3389/fpls.2025.1552625.
DOI: https://doi.org/10.3389/fpls.2025.1552625

Interpretive Summary: In apple growing it is often assumed that the same apple variety will be the same regardless of what rootstocks it is grafted on. We conducted a long term (17 year) field experiment using 5 apple varieties (‘Empire’, ‘Gala’, ‘Honeycrisp’, ‘Mustu’, and ‘Red Delicious’) grafted on 19 different rootstocks and showed that there is an interaction effect where some scion-rootstock combinations grow and produce far better than others. This interaction suggests that in order to optimize orchard performance, growers should conduct careful planning with regards to the selection of the best rootstock-scion combinations.

Technical Abstract: The interactive effect of different apple scions with commonly used rootstocks could result in growers selecting an inferior option for tree survival, yield, and fruit quality. The long-term tree performance and fruit quality interactions of 19 rootstocks (including Budagovsky, Geneva, and Malling series) and 5 apple cultivars (‘Empire’, ‘Gala’, ‘Honeycrisp’, ‘Mustu’, and ‘Delicious’) were explored in two orchards in Western New York. The first orchard examined the five cultivars on dwarfing rootstocks (B.9, CG.4210, G.11, G.16, G.202, G.41, G.65, G.814, M.26, M.9Pajam2, and M.9T337) and was planted at a spacing of 1.22 m x 3.66 m (2,243 trees ha-1). The second orchard examined the same cultivars on semi-dwarfing rootstocks (B.118, G.214, G.30, G.210, G.935, G.222, M.26, and M.7) and was planted at a spacing of 1.83 m x 4.27 m (1,282 trees ha-1). Following 17 years, the variables of tree mortality, growth, cumulative yield, and cumulative yield efficiency each resulted in a significant interaction between cultivar and rootstock in both orchards. There were no significant interactions on quality variables measured except fruit color of the 3 bi-colored ‘Gala’, ‘Honeycrisp’ and ‘Delicious’ for both the dwarfing and semi-dwarfing rootstocks. The implications of the interactions observed are that apple producers should pair specific rootstocks with specific cultivars to optimize orchard performance. Planting and maintaining orchards is an inherently long-term investment for growers and multiple decisions such as tree spacing, training system, cultivar, and rootstocks largely determine horticultural success and economic profitability.