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 Sep 2025
A recent Chinese study shows that combining tea polyphenols and nisin preserves the quality of “Brooks” and “Summit” cherries for up to 21 days. The treatment delays senescence and spoilage, offering a natural, effective and eco-friendly postharvest solution.
10 Jul 2025
Switzerland harvests 2,400 tonnes of cherries under the 'Nachhaltigkeit Früchte' programme. The new 2025 season marks a step forward for the environmental, economic and social sustainability of Swiss fruit growing, supported by retailers and politicians.
20 Aug 2026
U.S. tart cherry production is forecast at 91 million pounds in 2026, down 36% year on year. Spring freezes hit Michigan and Utah, cutting the crop and increasing pressure on inventories, processors, product availability and grower prices across the domestic market now.
20 Aug 2026
A study on sweet cherry dormancy combines plant physiology, metabolomics and NDVI/FAPAR vegetation indices from Sentinel and Landsat imagery, highlighting scalable tools to monitor canopy senescence, physiological activity and orchard phenology across the seasonal cycle.
