Evaluation of native hybrids of Prunus fruticosa Pall. as cherry interstocks

Abstract

Searching for growth reducing cherry rootstocks, researchers have produced and tested numerous hybrids of Prunus fruticosa Pall. Some of them have proved to be promising as dwarfing rootstocks in cherry growing. The native flora of Hungary is rich in native hybrids of Prunus fruticosa Pall. identified and described under different names, but this rich genetic diversity has never been evaluated and used as cherry rootstocks. A total of 25 native hybrids were identified in different locations of Hungary, clonally propagated and planted in the repository of our research station. Based on their phenotype characteristics they were identified as Prunus x mohácsyana Kárp., P. eminens, Prunus x jávorkae Kárp. (supposedly P. fruticosa x P. mahaleb) and Prunus fruticosa f. aucta Borb. Using the clones of the above mentioned hybrids as interstems, cherry trees of cultivar Sunburst were raised for field testing and planted into an orchard trial in spring 2000. The root of the trees was Prunus mahaleb. As control, Sunburst trees with Gisela 5 interstems were also planted. Growth of trees (trunk girth, canopy size), yield and fruit size were measured every year. Health status and incompatibility symptoms on trees and survival rate were also evaluated. Based on their growth, productivity and compatibility characteristics, three clones of P. eminens (3H, FV1 and KV2) and four clones of P. x mohácsyana Kárp. (3H, KV2, PZ2, PZ5) were selected for further evaluation as cherry rootstocks. We are aware that the selected interstems used later as rootstocks may differ in certain characteristics, but this pre-selection method seems to be a useful tool for selection in the hybrid screening stage.