From the cherry breeding conducted by Amy Iezzoni, professor emeritus at Michigan State University, five new dwarfing and early rootstocks have recently been commercially released: the Corette® series. All five rootstocks significantly reduce the size of the tree compared to standard rootstocks and entry into production occurs within the third year, two years earlier than traditional planting systems. These rootstocks have completed the experimentation phase in the USA both for sweet cherry, in very high density wall planting systems, and for sour cherries, using a high density production system and mechanized harvesting above the row.
The main characteristics of the Corette® series rootstocks are reported below (Iezzoni, 2022).
Dwarfing, precocity-inducing, clonal rootstock for cherry.
Origin: Michigan State University, East Lansing, by A. Iezzoni. Hybrid of unknown complexity involving Prunus avium, P. cerasus, and P. fruticosa. USPP 30,553; 4 June 2019.
Plant: vigor weak; branching habit spreading.
Rootstock performance: induces reduced vigor and increased precocity compared to trees budded on mazzard seedling rootstocks; vigor lower than Gisela® 5; grafted plants tend to produce root suckers; exhibits moderate sensitivity to high soil pH.
Dwarfing, precocity-inducing, clonal rootstock for cherry.
Origin: Michigan State University, East Lansing, by A. Iezzoni. Hybrid of unknown complexity involving P. avium, P. cerasus, and P. fruticosa. USPP 32,852; 2 Mar. 2021.
Plant: vigor weak; branching habit spreading.
Rootstock performance: induces reduced vigor and increased precocity compared to trees budded on mazzard seedling rootstocks; vigor lower than Gisela® 5; grafted plants tend to produce root suckers.
Dwarfing, precocity-inducing, clonal rootstock for cherry.
Origin: Michigan State University, East Lansing, by A. Iezzoni. (P. cerasus × P. canescens) O.P. USPP 30,538; 28 May 2019.
Plant: vigor weak; branching habit spreading.
Rootstock performance: induces reduced vigor and increased precocity compared to trees budded on mazzard seedling rootstocks; vigor similar to Gisela® 5; grafted plants produce no root suckers.
Dwarfing, precocity-inducing, clonal rootstock for cherry.
Origin: Michigan State University, East Lansing, by A. Iezzoni. P. cerasus × (P. cerasus × P. canescens). USPP 30,473; 7 May 2019.
Plant: vigor weak; branching habit spreading.
Rootstock performance: induces reduced vigor and increased precocity compared to trees budded on mazzard seedling rootstocks; vigor similar to Gisela® 5; grafted plants produce no root suckers.
Clonal rootstock for cherry.
Origin: Michigan State University, East Lansing, by A. Iezzoni. Hybrid of unknown complexity including P. avium and P. fruticosa. USPP 32,813; 16 Feb. 2021.
Plant: vigor weak; branching habit spreading.
Rootstock performance: induces reduced vigor and increased precocity compared to trees budded on mazzard seedling rootstocks; vigor lower than Gisela® 5; grafted plants tend to produce root suckers; exhibits tolerance to water stress compared to Gisela® 5.
L. Long, G. Lang, C. Kaiser (2020). Sweet Cherry. CABI Books
A. Iezzoni (2022). Cherry Rootstocks. Register of New Fruit and Nut Cultivars List 51. HORTSCIENCE
10 Apr 2024
The United States has banned the entry of cherries from Quebec, Canada, following the detection of the European cherry fruit fly in the province. The notice expands the 2017 import ban on cherries from Ontario. Other Canadian provinces must certify the origin of their cherries.
26 Sep 2025
A Greek study has developed a predictive model to estimate nutrient loss in cherry orchards. Based only on fresh fruit yield data, it enables more accurate and sustainable fertilization management while actively promoting recycling of pruning and leaf residues.
27 Apr 2026
The Jerte Valley cherry harvest starts with 18,000–20,000 tons expected, high quality and European exports from May. Awaiting China market opening in a season marked by promotion, automation and unstable logistics costs affecting growers and supply chains.
27 Apr 2026
Tasmania closes the 2025/26 cherry season with export values nearing $50 million, driven by strong Asian demand and higher prices. Hong Kong, China, and Taiwan lead growth, reinforcing the premium positioning of Tasmanian cherries globally.
