Juglans Rootstock Named 'Cliff Clone'

Abstract

A new and distinct Juglans cultivar named Cliff Clone is disclosed, characterized by an increased propensity to thrive in sandy soils which have been replanted into walnut. Trees grown on the new rootstock variety have shown significantly better vigor as well as increased walnut production when planted in the presence of the pathogen Pratylenchus vulnus and in soil known to have walnut replant disorder. The new variety is a Juglans hindsii x regia, for use as a commercial rootstock for grafting or budding onto.

Claims

1. A new and distinct cultivar of Juglans tree named Cliff Clone as herein illustrated and described.

Description

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

[0012] The accompanying photographs in FIG. 1 through FIG. 5 illustrate in full color typical plants of Cliff Clone grown in a greenhouse in Yuba City, Calif. The photographs were taken using conventional techniques and equipment. While the colors in these photographs may display variances of color as compared to the living cultivar, due to LRV (light reflectance value), they are as accurate as possible using conventional photographic techniques. Colors in the photographs may appear to differ slightly from the color values cited in the botanical description, which accurately describe the colors of the new Juglans plant. No artificial light, photoperiodic treatments or chemical treatments were given to the plants.

[0013] FIG. 1 illustrates in full color an un-grafted young tree at approximately 9 months of age.

[0014] FIG. 2 illustrates in full color newly planted rootstock plugs.

[0015] FIG. 3 illustrates in full color the trunk of a mature tree.

[0016] FIG. 4 illustrates in full color a comparison trial. The larger tree on the left side of the figure is Chandler grafted onto Cliff Clone rootstock. The tree in the same row, on the right side of the figure is Chandler grafted onto VX211 rootstock. Age of both trees is 30 months.

[0017] FIG. 5 illustrates in full color a different view of the same comparison trial. The larger tree on the right side of the figure is Chandler grafted onto Cliff Clone rootstock. The tree in the same row, on the left side of the figure is Chandler grafted onto VX211 rootstock. Age of both trees is 30 months.

DETAILED BOTANICAL DESCRIPTION

[0018] In the following description, color references are made to The Royal Horticultural Society Colour Chart 2007 except where general terms of ordinary dictionary significance are used. The following observations and measurements describe Cliff Clone plants grown outdoors in Yuba City, Calif. Growing conditions are similar to USDA Zone 9. Temperatures ranged from approximately 15 to 30 degrees C. during the day and 10 to 19 degrees C. at night. Measurements were taken from trees of various age, including 6 month old plugs, rootstock only plants of 5 months and a mature tree of 21 years. Age of the plant used is specified when measurements are given. Measurements and numerical values represent averages of typical plant types at corresponding age of maturity. [0019] Botanical classification: Juglans intergerrima x regia Cliff Clone.

PROPAGATION

[0020] Time to initiate roots: About 21 days at approximately 27 C. [0021] Root description(color, woody, fibrous, branching characteristics): Roots are fibrous and somewhat branched. Newly formed roots are delicate and fleshy, 1 to 2 mm in diameter. Mature roots are woody and more rigid. [0022] Propagation method: In-vitro propagation has been successful. [0023] Grafting information: Whip and tongue grafting has been found to have comparable success as with other walnut rootstocks.

PLANT

[0024] Time of year measurements taken: September. [0025] Height: Approximately 100 cm at one year. [0026] Plant spread: Approximately 56 cm at one year. [0027] Typical mature height: Grafted trees can reach a height of 15 meters or more. [0028] Typical mature spread: Grafted trees can attain a spread 10 meters or more. [0029] Overall tree shape: Oval to Pyramidal. [0030] Growth rate: Vigorous. Among the most vigorous walnut hybrid rootstocks. [0031] Growth habit: Upright, large deciduous tree. [0032] Branching characteristics: Not typically grown for above ground characteristics. To date trees have not been grown to allow typical branching. Sucker type branches emerge from trunk, which are propagated. [0033] Trunk: [0034] Diameter.Approximately 5.2 cm at 1 year. [0035] Texture.Smooth. [0036] Color.Near Yellow-Green 148A, at about 1 year. [0037] Lenticels.Density: Approximately 8 per cm.sup.2. Lenticel width: Approximately 0.08 cm. Lenticel color: Near RHS Greyed-Yellow 162D.

FOLIAGE

[0038] Leaf: [0039] Arrangement.Alternate occurring compound leaves. [0040] Compound leaf length.Average 39 cm. [0041] Compound leaf width.Average 20 cm. Leaflets: Shape: Oblanceolate. Quantity: Typically 11 or 13. Occurring in opposite pairs, with a single terminal leaflet. Average Overall Length: 9.3 cm. Average Overall Width: 3.6 cm. Attachment: Sessile. Apex: Acute to nearly acuminate. Base: Rounded to rounded-oblique. Margin: Slightly dentate. Texture of top surface: Smooth, veins not prominent. Texture of bottom surface: Glabrous, mid-rib densely canescent. Angle of attachment: Leaves are held at an angle approximately 10 to 25 degrees from perpendicular. Leaf internode length: Approximately 5.3 cm. Typical leaf fall date: 15 November at 40 latitude,50 meters elevation above mean sea level. Typical leaf emergence date: 20 March at 40 latitude,50 meters elevation above mean sea level. [0042] Color.Young foliage upper side: Near RHS Green 137B. Young foliage under side: Near RHS Yellow-Green 146B. Mature foliage upper side: Near RHS Yellow-Green 147A. Mature foliage under side: Near RHS Yellow-Green 146B. Fall foliage upper side: Near RHS Yellow 2B. Fall foliage under side: Near RHS Yellow 2C. [0043] Venation.Type: Venation color: Upper Surface: Near RHS Yellow-Green 152D. Lower Surface: Near RHS Yellow-Green 146D. [0044] Petiole: [0045] Length.Approximately 30 cm. [0046] Diameter.Approximately 0.35 cm. [0047] Color.Near RHS Yellow-Green 146C. [0048] Texture.Smooth. [0049] Leaflet petiole: [0050] Length.0.5 mm. [0051] Diameter.Approximately 0.15 cm. [0052] Color.Near RHS Yellow-Green 152C. [0053] Texture.Smooth, glabrous.

FLOWER Flowering not observed to date.

REPRODUCTIVE ORGANS Not observed to date.

OTHER CHARACTERISTICS

[0054] Seeds and fruits: Not observed to date. [0055] Disease resistance: Appears to adequately tolerate Replant disease more than other walnut rootstocks, exhibiting equivalent or better growth than other walnut rootstocks. Grows as good or better than other walnut rootstocks in the presence of Lesion Nematode, Pratylenchus vulnus. [0056] Temperature tolerance: Low temperature tolerance to approximately 9 C. Tolerates high temperature to at least 46 C. [0057] Drought tolerance: Based on growth and graft success performance in extremely sandy soils, drought resistance appears slightly superior to other walnut hybrid rootstocks.