Abstract:
A new and distinct variety of  Persea americana  tree is provided. A vigorous moderately-spreading upright growth habit is exhibited. The tree is less alternate bearing than the widely-grown ‘Hass’ variety (non-patented in the United States). The fruit is ellipsoid-shaped, lacks shoulders, is generally black-skinned, is well distributed around the tree, and commonly is larger than that of the ‘Hass’ variety. The leaves are displayed in a greater quantity than the ‘Hass’ variety and are similar in appearance to those of the ‘Hass’ variety. Moderate resistance to Persea mites is exhibited. The variety is suitable for the production of quality avocado crop under commercial growing conditions.

Description:
BOTANICAL CLASSIFICATION  
         [0001]    [0001] Persea americana  Mill.  
         VARIETY DENOMINATION  
         [0002]    ‘GEM’.  
         SUMMARY OF THE INVENTION  
         [0003]    The invention relates to new and distinct variety of Avocado tree that was originally designated 3-29-5 and subsequently has been named ‘GEM’.  
           [0004]    The seed that produced the new variety of the present invention was collected in 1985 from open-pollinated avocado trees of the ‘Gwen’ variety (U.S. Plant Pat. No. 5,298) growing at Riverside and Irvine, Calif. The exact pollen parent is unknown. Seeds were planted in a test planting area at Ventura County, Calif. to produce avocado seedings in the spring of 1986. The resulting seedling plants were observed and studied and a single plant of the new variety was discovered. Had the new variety not been discovered and carefully preserved it would have been lost to mankind. During about 1992 at the Southcoast Research and Extension Center of the University of California located at Irvine, Calif., the new variety was first top worked by grafting on  Persea americana  seedlings. This and subsequent asexual propagation has confirmed that the new variety is stable and that the progeny are formed true to type.  
           [0005]    It was found that the new variety of the present invention exhibits the following combination of characteristics:  
           [0006]    (a) exhibits a vigorous moderately-spreading upright growth habit,  
           [0007]    (b) is less alternate bearing than the ‘Hass’ variety (non-patented in the United States) and fruits well every year,  
           [0008]    (c) forms ellipsoid-shaped generally black-skinned fruit that is well distributed around the tree which lacks shoulders, commonly is larger than that of the ‘Hass’ variety, and matures at approximately the same time as the fruit of the ‘Hass’ variety having yellow-green flesh of excellent eating quality that is free of obvious fibers,  
           [0009]    (d) forms leaves in greater quantity than the ‘Hass’ variety that are similar in appearance to those of the ‘Hass’ variety, and  
           [0010]    (e) displays moderate resistance to the Persea mite.  
           [0011]    The new ‘GEM’ variety can be distinguished from all previously known avocado varieties including the ‘Hass’ variety, the ‘Gwen’ variety, the ‘Sir Prize’ variety (U.S. Plant Pat. No. 9,709), the ‘Lamb Hass’ variety (U.S. Plant Pat. No. 9,753), and the ‘Harvest’ variety (U.S. Plant patent application Ser. No. ______, filed Mar. 14, 2002) in view of its distinctive combination of characteristics.  
           [0012]    The new ‘GEM’ variety is believed to be well suited for the production of quality avocados under commercial growing conditions.  
       
    
    
     BRIEF DESCRIPTION OF THE PHOTOGRAPHS  
       [0013]    The accompanying photographs show specimens of the tree and plant parts of the new ‘GEM’ variety. The trees had been grafted on seedling  Persea americana  understock.  
         [0014]    [0014]FIG. 1 illustrates a typical six year-old tree of the ‘GEM’ variety while growing at Irvine, Calif. The moderately spreading upright growth habit with relatively dense foliage is shown.  
         [0015]    [0015]FIG. 2 illustrates typical foliage of the ‘GEM’ variety as displayed during the summer. Dimensions in centimeters and inches are shown at the right.  
         [0016]    [0016]FIG. 3 illustrates typical external and internal views of the fruit of the ‘GEM’ variety at the right center. For comparative purposes the fruit of the ‘Sir Prize’, ‘Hass’, ‘Lamb Hass’ and ‘Harvest’ varieties also is included. 
     
    
     DETAILED DESCRIPTION  
       [0017]    The following is a detailed description of the new ‘GEM’ variety. The trees were being grown at experimental orchards of the University of California located at Irvine, Calif., were approximately six years of age, and had been grafted on  Persea americana  seedling understock. When reference to other varieties appears for comparative purposes, such varieties were approximately six years of age with the possible exception of the ‘Gwen’ variety. The comparative trees of ‘Gwen’ variety were mature and their exact age was unknown.  
         [0018]    BOTANICAL CLASSIFICATION  Persea americana , var. ‘GEM’.  
         [0019]    TREE  
         [0020]    [0020] Growth Habit.— Vigorous upright with moderate spreading. This can be compared to spreading for the ‘Hass’ variety, moderately-spreading for the ‘Gwen’ variety, and open and spreading for the ‘Harvest’ variety.  
         [0021]    [0021] Height.— Approximately 4.5 m on average. This can be compared to an average height of 4.6 m for the ‘Hass’ variety, 3.5 m for the ‘Gwen’ variety, and 4.8 m for the ‘Harvest’ variety.  
         [0022]    [0022] Width.— Approximately 3.5 m on average. This can be compared to an average width of 4.3 m for the ‘Hass’ variety, 3.3 m for the ‘Gwen’ variety, and 4.0 m for the ‘Harvest’ variety.  
         [0023]    [0023] Bark.— Substantially identical to that the ‘Hass’, ‘Gwen’, and ‘Harvest’ varieties.  
         [0024]    [0024] Trunk Size.— Approximately 51.0 cm in circumference on average. This can be compared to an average circumference of 57.6 cm for the ‘Hass’ variety, 38.9 cm for the ‘Gwen’ variety, and 64.5 cm for the ‘Harvest’ variety.  
         [0025]    LEAVES:  
         [0026]    [0026] Shape.— Generally lanceolate with an acute tip and an acute base. The shape is substantially the same as that of the ‘Hass’ and ‘Gwen’ varieties. This can be compared to more oval with an acute tip and an acute base for the ‘Harvest’ variety.  
         [0027]    [0027] Length.— Approximately 15.4 cm on average. This can be compared to 18.0 cm for the ‘Hass’ variety, 16.0 cm for the ‘Gwen’ variety, and 15.4 cm for the ‘Harvest’ variety on average.  
         [0028]    [0028] Width.— Approximately 5.9 cm on average. This can be compared to 6.4 cm for the ‘Hass’ variety, approximately 5.6 cm for the ‘Gwen’ variety, and approximately 6.5 cm for the ‘Harvest’ variety on average.  
         [0029]    [0029] Leaf Weight.— Approximately 1.78 g on average. This can be compared to approximately 2.67 g for the ‘Hass’ variety, approximately 1.73 g for the ‘Gwen’ variety, and approximately 2.17 g for the ‘Harvest’ variety on average.  
         [0030]    [0030] Color.— Medium green and lighter on the under surface.  
         [0031]    [0031] Margin.— Entire and wavy.  
         [0032]    FLOWERS  
         [0033]    [0033] Type.— Synchronous dichogamy, and borne in panicles.  
         [0034]    [0034] Opening.— Open as female on the morning of the first day, and close in late morning or early afternoon. Such flowers generally remain closed until the afternoon of the second day when they open as male. Such opening sequence commonly is designated as being the “Type A”. This flowering behavior is believed to promote cross-pollination since the male and female phases of an individual flower occur at different times. Accordingly, the interplanting of complementary flower types possibly boosts fruit set and yield by making pollen available at the appropriate time. Bees (e.g., European honey bees) can be used to advantage as pollinators.  
         [0035]    FRUIT  
         [0036]    [0036] Pick Dates.— Commonly March to July or August. This compares to February to July or August for the ‘Hass’ variety, late February or March into June for the ‘Gwen’ variety, and fall into early winter for the ‘Harvest’ variety.  
         [0037]    [0037] Bearing.— Less alternate bearing than the ‘Hass’ variety, and commonly fruits well every year. The fruit is well distributed around the tree and tends to be protected inside the leaf canopy.  
         [0038]    [0038] Shape.— Ellipsoid. The ‘Hass’ fruit configuration has been found to vary from ellipsoid to obovate from year to year. The ‘Gwen’ and ‘Harvest’ fruit configuration is generally inverted high spheroid.  
         [0039]    [0039] Base.— Inflated.  
         [0040]    [0040] Apex.— Rounded.  
         [0041]    [0041] Size.— Generally larger than that of the ‘Hass’ variety. An average fruit weight was found to be 235 g. This can be compared to 204 g for the ‘Hass’ variety, 210 g for the ‘Gwen’ variety, and 232 g for the ‘Harvest’ variety.  
         [0042]    [0042] Skin Color.— Very attractive and generally black with numerous light yellow-green lenticels (as illustrated in FIG. 3).  
         [0043]    [0043] Flesh Color.— Yellow-green with more green towards the skin.  
         [0044]    [0044] Texture.— Slightly pebbled. The environment has been found to influence the roughness of the skin surface.  
         [0045]    [0045] Percent Dry Weight.— This is an indirect measure of the oil content of the avocado fruit. 29.48 percent dry matter on average with a maximum of 36.17 percent on Sep. 4, 2001. This compares to 28.77 percent dry matter on average for ‘Hass’ with a maximum of 35.01 percent on Jul. 23, 2001, and 22.35 percent dry matter on average for ‘Harvest’ with a maximum of 27.21 percent on Oct. 24, 2001.  
         [0046]    [0046] Skin Character.— Pliable.  
         [0047]    [0047] Skin Thickness.— Approximately 1.6 mm on average. This can be compared to 1.6 mm for the ‘Hass’ variety, 1.3 mm for the ‘Gwen’ variety, and 1.7 mm for the ‘Harvest’ variety on average.  
         [0048]    [0048] Skin Separation.— Separates readily and cleanly from the flesh when ripe.  
         [0049]    [0049] Seed/Skin/Flesh Ratio by Weight.— Approximately 16:13:71. This can be compared to 14:13:73 for the ‘Hass’ variety, 18:13:69 for the ‘Gwen’ variety, and 19:16:65 for the ‘Harvest’ variety.  
         [0050]    [0050] Flavor.— Eating quality is excellent and similar to that of the ‘Hass’ variety. The flavor is slightly less nutty than the ‘Hass’ variety and possesses a buttery texture. The flavor of the ‘Gwen’ fruit also is generally comparable to that of the ‘Hass’ variety and is considered to be slightly better by some. The fruit flavor of the ‘Harvest’ variety when fully mature possesses a less nutty flavor and tends to possess a bitter/sweet taste when immature.  
         [0051]    [0051] Fruit Fibers.— No obvious fruit fibers are apparent.  
         [0052]    [0052] Seed Shape.— Broadly ovate. This compares to variable mostly ellipsoid for the ‘Hass’ variety, and spheroid for the ‘Gwen’ and ‘Harvest’ varieties. Seed Weight.—Approximately 36.0 g on average. This compares to 28.4 g for the ‘Hass’ variety, 38.8 g for the ‘Gwen’ variety, and 41.2 g for the ‘Harvest’ variety on average.  
         [0053]    [0053] Seed Ratio.— Generally comparable to that of the ‘Hass’ variety.  
         [0054]    PRODUCTIVITY Generally equal to or greater than that of the ‘Hass’ variety combined with a significantly reduced alternate bearing aspect as previously indicated. Accordingly, more regular high yields are made possible to growers.  
         [0055]    RESISTANCE TO PESTS Moderately resistant to the Persea mite and such resistance is believed to be greater than that of the ‘Hass’ variety and less than that of the ‘Lamb Hass’ variety.  
         [0056]    HARDINESS Generally comparable to that of the ‘Hass’ variety. For comparative purposes the ‘Gwen’ and ‘Harvest’ varieties are believed to be somewhat less hardy.