Mahaleb rootstock named `UCMH 59`

Abstract

A new and distinct cultivar of Prunus mahaleb is provided. The new cultivar is particularly well suited for serving as an understock during cherry production. A number of advantages are provided when compared to the standard Mahaleb rootstock. The cultivar is readily amenable to vegetative propagation (e.g., by the use of softwood cuttings), and exhibits some improved resistance to Phytophthora spp. When used with a `Bing` cherry scion, increased yields and yield efficiency have been observed without reduced fruit size. Improved precocity in bearing is displayed when compared to the standard Mahaleb rootstock. The new cultivar when grown without use as an understock forms a larger and more vigorous tree than the `UCMH 55` and `UCMH 56` cultivars that were products of the same research program. When used as a rootstock, the new cultivar produces a compact tree with a size reduction of approximately 20 to 25 percent compared to that produced when using a standard Mahaleb rootstock. Few suckers are produced.

Description

Botanical / commercial classification: Prunus mahaleb / Mahaleb Rootstock.Varietal denomination: cv. `UCMH 59`.SUMMARY OF THE INVENTIONMahaleb rootstocks (i.e., Prunus mahaleb rootstocks) are widely used during both sweet and sour cherry production throughout the world. It has been the common practice to form such rootstock plants from seed following the random outcrossing of parent plants. Accordingly, cherry production encountered when using such plants as an understock has tended to be somewhat variable due to differences in the genotype of the understock. Such variation often has led to reduced field performance on some cherry trees on a random and unpredictable basis. Mahaleb rootstocks in the past have generally been found to be incapable of vegetative propagation on a reliable basis, such as through the use of softwood and hardwood cuttings. Also, such rootstocks in the past have been susceptible to root and crown fungal diseases generally known as Phytophthora spp.SUMMARY OF THE...

AI Technical Summary

Benefits of technology

It was an object of my research to provide Prunus mahaleb rootstocks that possess characteristics that overcome shortcomings of the Mahaleb rootstock presently being used during cherry production. More specifically, it was my goal to provide cherry rootstocks that could be vegetatively propagated in an expeditious and reliable manner so that cherry growers can eliminate crop variation that can be traced to lack of uniformity in the rootstock. Also, it was a goal of my research to provide new Mahaleb rootstocks that inherently display needed resistance to disease and thereby make possible a satisfactory cherry crop on a more consistent basis combined with a reduction in the need to replant because of tree loss that is traceable to disease.

It was found that the new Prunus mahaleb cultivar of the present invention exhibits the following combination of characteristics: (a) readily is amenable to vegetative propagation, (b) performs well as an understock for cherry production, (c) forms a larger and more vigorous tree than the `UCMH 55` cultivar and the `UCMH 56` cultivar, (d) when used as an understock produces a compact tree with a size reduction of approximately 20 to 25 percent, (e) displays some improved resistance to Phytophthora spp., (f) makes possible increased `Bing` sweet cherry scion yield and yield efficiency without reduced fruit size when comapred to the standard Mahaleb rootstock, (g) demonstrates improved precocity in bearing when compared to the standard Mahaleb rootstock, and (h) produces few suckers.

In view of the above combination of characteristics, the new cultivar of the present invention well meets the needs of cherry producers for use as an improved rootstock. Cherry scion characteristics are no longer influenced by variation in the Mahaleb rootstock resulting from the random outcrossing of parental plants. Also, the disease resistance made possible by the new cultivar is a major advantage for cherry producers.

The new cultivar of the present invention has been repeatedly reproduced through the use of softwood and hardwood cuttings at Davis, Calif., U.S.A. Such propagation has confirmed that the characteristics of the new cultivar are stable and are firmly fixed and are transmitted to subsequent generations on a reliable basis.

Problems solved by technology

Such variation often has led to reduced field performance on some cherry trees on a random and unpredictable basis.

Mahaleb rootstocks in the past have generally been found to be incapable of vegetative propagation on a reliable basis, such as through the use of softwood and hardwood cuttings.

Also, such rootstocks in the past have been susceptible to root and crown fungal diseases generally known as Phytophthora spp.

Had this plant not been discovered and preserved, it would have been lost to mankind.

Images