Abstract:
A new and distinct  Persea americana  variety having strong resistance to  Phytophthora cinnamomi  when used as a rootstock. It is a relatively slow growing rootstock having a heavy yield, appearing to have a high yield/canopy volume ratio. ‘Steddom’ has a small degree of salt tolerance and appears to be an all-around, excellent rootstock with small stature and low vigor, making it desirable for high density or hedge-row avocado plantings.

Description:
Latin name of the genus and species: The avocado cultivar of this invention is botanically identified as  Persea americana  Mill. 
     Variety denomination: The variety denomination is ‘Steddom’. 
     BACKGROUND OF THE INVENTION 
     Avocado root rot is the limiting factor for the growth of avocados throughout the world. Avocado root rot is caused by the fungus  Phytophthora cinnamomi , which attacks and kills the feeder roots of avocado trees. The resultant lack of roots causes the tree to eventually die from water stress. There are a number of varieties of rootstocks that have some tolerance to the disease. These varieties included ‘Duke 7’ (unpatented), the most commonly planted tolerant rootstock in the world; and ‘Thomas’ (U.S. Plant Pat. No. 6,628), another root rot tolerant rootstock. However, even with these rootstocks, growers must still use a variety of methods, including mounding, mulching and the applications of chemical fungicides, to keep the tress from dying in many soils. More resistant rootstocks are necessary to eliminate avocado root rot as a major disease threat. 
     Screening and Greenhouse Evaluation of Rootstocks 
     ‘Steddom’ was identified and characterized using the following screening protocol. As it is difficult to breed avocados because only one in approximately one thousand flowers actually set fruit, plant breeding blocks of avocados were isolated to prevent out-crossing with susceptible rootstocks. The breeding blocks were made up of various combinations of selected rootstocks including, ‘Thomas’ (U.S. Plant Pat. No. 6,628), ‘Barr Duke’ (U.S. Plant Pat. No. 6,627), ‘G6’, ‘Duke 7’, ‘Duke 9’, ‘UC 2001’, ‘UC 2011’, ‘Toro Canyon’ (U.S. Plant Pat. No. 5,642), ‘Spencer’, ‘CR1-71’, ‘G 810’, ‘G 875’, ‘G 755A’, ‘VC 256’, and ‘Steyemarkii’. In order to synchronize blooming, attempts were made to girdle late-blooming varieties and spray early-blooming varieties with the pesticide Unicona-zole-P. 
     Initial screening was carried out by germinating seeds, which were harvested from the breeding blocks, in flats of vermiculite in the greenhouse.  Phytophthora cinnamomi -infested millet was placed in rows along with the young roots of the test seedlings. After 8-10 weeks roots were evaluated and those with a high percentage of surviving roots were transplanted to soil mix incorporated with  P. cinnamomi -infested millet. Rootstocks that survived this test were planted and grown in  P. cinnamomi -infested soils. Survivors were examined more carefully for various types of resistance using asexual propagated material.
         a. Root survival—Rootstocks were grown in typical California avocado soils, inoculated with  P. cinnamomi  and evaluated for growth, root length and percent healthy roots.   b. Root regeneration—Rootstocks were grown in soil inoculated with  P. cinnamomi , treated with Aliette to halt  Phytophthora  root rot and evaluated for root regeneration.   c. Attraction to  P. cinnamomi —Roots of the rootstocks were placed in water baths with motile zoospores of  P. cinnamomi . The numbers of spores attracted to the roots were evaluated.       

     Rootstocks that performed well in the screening and greenhouse evaluations were further tested under field conditions. 
     Selection of ‘Steddom’ 
     ‘Steddom’ was developed at Riverside, Calif. The maternal parent is ‘Toro Canyon’ (U.S. Plant Pat. No. 5,642) avocado variety. The pollen parent is unknown. Specifically, the ‘Steddom’ rootstock variety was selected in 1994 from an agricultural operations land located Riverside, Calif. The fruit were collected from the avocado breeding blocks, the seed removed, and planted in vermiculite. The seeds were grown in a greenhouse. The plants were inoculated with the fungus  Phytophthora cinnamomi . After showing tolerance to the disease, ‘Steddom’ was selected as a single plant for further testing. Budwood was collected from the plants and grafted to the stumps of adult avocado trees that had been cut down at Irvine Calif. The new varieties grew into trees which provided budwood for further testing. At least two ‘mother’ trees of the variety are growing in Irvine Calif., along with the germplasm. During screening and evaluation, ‘Steddom’, which was selected and originally designated ‘PP24’, distinguished itself from other varieties, including the maternal parent ‘Toro Canyon,’ by having a high tolerance against  Phytophthora  root rot. The properties of ‘Steddom’ were found to be true to type and transmissible by asexual reproduction. 
     BRIEF SUMMARY OF THE INVENTION 
     This invention relates to a new and distinct avocado variety. ‘Steddom’ is an avocado tree having a rootstock that has a high tolerance against  Phytophthora  root rot. It is a relatively slow growing rootstock and that yields heavily, and has a high yield/canopy volume ratio. ‘Steddom’ has a small degree of salt tolerance and appears to be an all-around, excellent rootstock with small stature and low vigor. For these reasons it may be an excellent choice for high density or hedge-row avocado plantings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a eight-year-old top-worked tree of the ‘Steddom’ variety while growing in Irvine, Calif. 
         FIG. 2  illustrates typical mature foliage of the ‘Steddom’ variety with dimensions in centimeters shown at the bottom. 
         FIG. 3  illustrates typical flush foliage of the ‘Steddom’ variety with dimensions in centimeters shown at the bottom. 
         FIG. 4A  illustrates typical inflorescence with dimensions in centimeters shown at the right and  FIG. 4B  illustrates typical inflorescence by itself. 
         FIG. 5  illustrates a typical external view of the fruit of the ‘Steddom’ variety, with dimensions in centimeters shown at the bottom. 
         FIG. 6  illustrates typical internal views of the fruit of the ‘Steddom’ variety, with and without the seed. Dimensions in centimeters are shown at the bottom. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following is a detailed description of the new ‘Steddom’ variety, which was taken from an approximately eight-year-old mature tree, with the exception as a rootstock for a specific scion when reference is made to root rot resistance and salinity tolerance. The tree is located in an experimental orchard in Irvine, Calif. and is grafted on a  Persea americana  seedling used as a rootstock. 
     The Royal Horticultural Society (R.H.S.) Colour Chart is used herein for the color description of the rind, seed, bark, leaf, flower, flesh color and other interest of the ‘Steddom’ avocado tree. 
     Trees, Foliage, and Flowers 
     
         
         Tree:
             Growth habit .—Vigorous and upright when compared to the rootstock ‘Thomas’.     Vigor .—Below are data on the vigor of ‘Hass’ grafted onto the rootstock ‘Steddom’, as determined by trunk diameter measurements from trees planted in an orchard with  Phytophthora cinnamomi  in Escondido Calif.       
     
       
    
     
       
         
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 Trunk diameter (cm) 
               
             
          
           
               
                 Rootstock 
                 year 1 
                 year 2 
                 year 3 
                 year 4 
                 year 5 
               
               
                   
               
               
                 PP # 24. 
                 2.37 
                 3.98 
                 7.07 
                 8.60 
                 11.23 
               
               
                 ‘Thomas’ 
                 2.44 
                 4.29 
                 6.75 
                 8.40 
                 10.84 
               
               
                   
               
               
                 Escondido Ca., with Hass scion 
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
               
               
               
             
           
               
                 TABLE 2 
               
             
             
               
                   
               
               
                 Canopy volume (cubic feet) 
               
             
          
           
               
                   
                 Rootstock 
                 year 1 
                 year 2 
                 year 3 
                 year 4 
                 year 5 
               
               
                   
                   
               
               
                   
                 PP # 24. 
                 14.00 
                 100.40 
                 376.1 
                 478. 
                 1257 
               
               
                   
                 ‘Thomas’ 
                 13.56 
                  84.48 
                 388.5 
                 367. 
                 1076 
               
               
                   
                   
               
               
                   
                 Escondido Ca., with Hass scion 
               
             
          
         
       
         
         
           
             
               
                   Size .—Medium. The typical canopy size of a three year old top-worked ‘Thomas’ is 388 cu.ft. By comparison the canopy size of a three year old top-worked ‘Steddom’ is 376 cu. ft. The tree is 610-915 cm in height when fully grown at the orchard site in Irvine, Calif. 
               
             
           
         
         Branch:
             Color .—The color of the one year old branch is yellow-green (RHS 144C).     Smoothness .—The bark of a one year old branch is smooth.     Lenticels .—The lenticels of a one year old branch are conspicuous.       
     
         Main stem:
             Color .—Brown (RHS N 200D and 197A).     Texture of bark .—Corky.       
     
         Young shoot (flush):
             Intensity of anthocyanin coloration .—Weak.     Anthocyanin coloration .—Orange-brown (RHS 172A).     Color .—Yellow-green (RHS 145C).     Conspicuousness of lenticels .—Medium.     Color of lenticels .—Red-purple (RHS 61A).     Size of lenticels.— 1.0-3.0 mm long.     Concentration of lenticels.—+/− 24 lenticels per square cm.     Color of upper side .—Yellow-green (RHS 146A).     Glossiness of upper side .—Medium.     Color of lower surface .—Green (RHS 139D).       
     
         Mature leaf:
             Length.— 18.0 cm.     Width.— 7.0 cm.     Ratio length/width.— 2.6.     Shape .—Lanceolate.     Color of upper side .—Green (RHS 143A).     Color of lower side .—Green (RHS 145B).     Glossiness of upper side .—Medium.     Prominence of veins on lower side .—Prominent and in relief.     Color of veins .—Yellow-green (RHS 151A).     General shape and cross-section .—Asymmetrically folded.     Reflexing of apex .—Present.     Color of petiole .—Yellow-green (RHS 144A).     Anise aroma .—Present.     Margin .—Undulation of margin is weak, and the leaf margin is entire.     Leaf apex shape .—Acuminate.     Leaf base shape .—Lanceolate.     Length of leaf petiole .—Approximately 4.5 cm.     Diameter of leaf petiole .—Approximately 3.0 mm.     Leaf arrangement .—Upright.       
     
         Flower:
             Bud size .—Approximately 5 mm in length and approximately 3 mm in diameter.     Bud shape .—Ovoid.     Bud color .—Yellow-green (RHS 152C).     Opening .—Belongs to group “A”, male opening (i.e. with mature stamens) occurs in the afternoon, the flower closes over night, and female opening (i.e. with mature pistil) occurs the next morning; the flower&#39;s opening cycle lasts 20-24 hours.     Petals .—Borne in two whorls of three perianth lobes. The petals possess entire margins and petal coloration is near yellow-green (RHS 150B). Both the upper and lower petal surfaces are near yellow-green (RHS 150B).     Stamen .—There are commonly nine fertile stamens with each having two basal nectar glands that are grayed-orange (RHS 174A) in color and three staminodia. The anthers are tetrathecal.     Pistil .—The single pistil with a slender style and small stigmatic surface has one carpel with one ovule. The ovary is superior.     Sepals .—There are 6 sepals which are approximately 4 mm in length and approximately 2 mm in width, and the color of both sepal surfaces is near yellow-green (RHS 151A).     Pedicel .—Commonly approximately 7 mm in length and approximately 1.8 mm in diameter. The coloration is near yellow-green (RHS 151A).     Peduncles .—Approximately 4.2 cm in length and approximately 5.0 mm in diameter. The coloration is near yellow-green (RHS 151A).     Number of flowers on inflorescence .—Approximately 185-205 flowers per inflorescence.     Fragrance .—Absent.     Bloom .—Bloom period at Riverside, Calif. experiment station varies with cultural conditions. On average ‘Steddom’ has been found to bloom from 1st of February through 20th of March.
 
Fruit, Fruit and Production Characteristics
       
     
         Fruit:
             Length.— 9.7 cm.     Width.— 5.4 cm.     Ratio length/width.— 1.8.     Weight .—78.9 grams.     Shape .—Pyriform, with the fruit apex being pointed with a diameter of approximately 2.4 cm and the base being rounded with a diameter of approximately 5.4 cm.     Color of skin  ( when ripe ).—Green (RHS 141B).     Texture of skin .—Smooth.     Presence of longitudinal ridges .—Absent.     Thickness of skin .—Thin.     Adherence of skin to flesh .—Medium.     Main color of flesh .—Yellow-green (RHS 154D).     Color of intensely colored area of flesh next to skin .—Green (RHS 141C).     Width of intensely colored area next to skin.— 3.0 mm.     Conspicuousness of fibers in flesh .—Inconspicuous.       
     
         Seed:
             Length.— 4.5 cm.     Width.— 4.0 cm.     Weight.— 16.9 grams.     Shape  ( in longitudinal section ).—Ovate.     Shape  ( in cross section ).—Circular.     Color of seed coat  ( fresh ).—Grayed-yellow (RHS 162B).     Cotyledon color .—Orange-white (RHS 159B).     Time of harvesting .—‘Steddom’ fruits ripen in September (in Riverside Calif.).     Resistance to pests .—Strong resistance to  Phytophthora cinnamomi.        Tolerance to salinity .—Moderate.     Market use .—The fruit of ‘Steddom’ are not intended for market use, but rather the variety is used as a rootstock onto which commercial varieties, such as ‘Hass’ are grafted.       
     
       
    
     
       
         
               
             
               
               
               
             
           
               
                 TABLE 3 
               
               
                   
               
               
                 ‘Steddom’ Rootstock Trials as of 2004 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 San Diego County 
                 Santa Barbara County 
               
               
                   
                 Ventura County 
                 San Luis Obispo County 
               
               
                   
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 4 
               
               
                   
               
               
                 Summary of the performance of the ‘Steddom’ avocado rootstock in 
               
               
                   Phytophthora -infested soil 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Health ranking/# 
                 Trials with health  
                 Yield ranking/# 
               
               
                   
                 rootstocks in 
                 rating below 1.5 1   
                 rootstocks in 
               
               
                 Rootstock trial 
                 trial (1 is best) 
                 (0-5; 5 = dead) 
                 trial (1 is best) 
               
               
                   
               
               
                 San Diego Co. 
                   
                   
                   
               
               
                 Location 1 
                 1/4 
                 + 
                 1/4 
               
               
                 Location 2 
                  8/15 
                 + 
                  1/15 
               
               
                 Location 3 
                  5/13 
                 + 
                 None 
               
               
                 Location 4 
                 1/4 
                 + 
                 1/4 
               
               
                 Location 5 
                  7/10 
                 + 
                  3/10 
               
               
                 Location 6 
                 1/3 
                 + 
                 1/3 
               
               
                 Ventura Co. 
                   
                   
                   
               
               
                 Location 1 
                  3/12 
                 + 
                  3/12 
               
               
                 Location 2 
                  9/10 
                 + 
                  2/10 
               
               
                 Santa Barbara Co. 
                   
                   
                   
               
               
                 Location 1 
                  3/10 
                 + 
                  3/10 
               
               
                   
               
             
          
           
               
                   
                   
                 Actual yield 
                 Rated higher than 
               
               
                   
                   
                 ranking/# rootstocks 
                 ‘Thomas’ 2   
               
               
                   
                 Rootstock trial 
                 in trial (1 is best) 
                 (control) 
               
               
                   
               
               
                   
                 San Diego Co. 
                   
                   
               
               
                   
                 Location 1 
                 None 
                 + 
               
               
                   
                 Location 2 
                 6/15 
                 + 
               
               
                   
                 Location 3 
                 None 
                 + 
               
               
                   
                 Location 4 
                 None 
                 + 
               
               
                   
                 Location 5 
                 None 
                 + 
               
               
                   
                 Location 6 
                 None 
                 + 
               
               
                   
                 Ventura Co. 
                   
                   
               
               
                   
                 Location 1 
                 None 
                 + 
               
               
                   
                 Location 2 
                 None 
                 - 
               
               
                   
                 Santa Barbara Co. 
                   
                   
               
               
                   
                 Location 1 
                 None 
                 + 
               
               
                   
               
               
                   1 1.5 health rating is the value that we would assign to trees not meeting grower approval under field conditions. 
               
               
                   2 ‘Thomas’ is considered the best commercial avocado rootstock for planting in  Phytophthora -infested soil. 
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 5 
               
             
             
               
                   
               
               
                 Rootstock rating at Santana,  
               
               
                 Ventura County, August 2001 1   
               
             
          
           
               
                   
                   
                 Tree rating 
                 Canopy 
                 Trunk  
                 No.  
               
               
                   
                   
                 (0-5;  
                 volume  
                 diameter 
                 trees  
               
               
                   
                 Rootstock 
                 5 = dead) 
                 (cu ft) 
                 (cm) 
                 dead 
               
               
                   
                   
               
               
                   
                 ‘Steddom’ 
                 0.80 a 
                 13.89 a 
                 1.92 a 
                 1 
               
               
                   
                 ‘Merensky II’ 
                 0.90 a 
                 15.10 a 
                 1.48 a 
                 1 
               
               
                   
                 ‘Uzi’ 
                 0.90 a 
                 16.92 a 
                 2.02 a 
                 0 
               
               
                   
                 ‘Zentmyer’ 
                 1.05 a 
                 16.48 a 
                 2.05 a 
                 1 
               
               
                   
                 ‘G755A (Brokaw)’ 
                 1.65 a 
                  5.55 a 
                 1.62 a 
                 1 
               
               
                   
                 ‘Medina’ 
                 1.90 a 
                 12.66 a 
                 1.70 a 
                 2 
               
               
                   
                 ‘Berg’ 
                 2.20 a 
                 13.80 a 
                 1.29 a 
                 4 
               
               
                   
                 ‘McKee’ 
                 2.35 a 
                  9.05 a 
                 1.52 a 
                 1 
               
               
                   
                 ‘Duke 7’ 
                 2.50 a 
                 11.40 a 
                 1.24 a 
                 4 
               
               
                   
                 ‘Thomas’ 
                 2.65 a 
                 10.22 a 
                 1.15 a 
                 4 
               
               
                   
                 ‘G755 A (C&amp;M)’ 
                 2.75 a 
                 11.66 a 
                 1.49 a 
                 2 
               
               
                   
                 ‘UC 2023’ 
                 3.00 a 
                  6.21 a 
                 1.25 a 
                 3 
               
               
                   
                   
               
               
                   
                   1 Mean values in each column followed by identical letters are not statistically different according to Waller&#39;s k-ratio t test. 
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 6 
               
               
                   
               
               
                 Rootstock rating at Santana, Ventura County, November 2002. 
               
               
                 Two-year trial to-date. 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Tree rating 
                 Canopy 
                 Trunk 
                 Fruit rating 
               
               
                   
                 (0-5; 
                 volume 
                 diameter 
                 (0-5; 
               
               
                 Rootstock 
                 5 = dead) 
                 (cu ft) 
                 (cm) 
                 5 = heavy) 
               
               
                   
               
               
                 ‘Merensky II’ 
                 0.17 d  
                 72.27 abc  
                 3.49 ab  
                  0.78 bcd 
               
               
                 ‘Uzi’ 
                 0.50 cd  
                 69.64 abcd 
                 3.64 a   
                 2.50 a 
               
               
                 ‘Steddom’ 
                 1.00 bcd 
                 67.95 abcd 
                 2.94 abc  
                  1.70 abc 
               
               
                 ‘Medina’ 
                 1.06 bcd 
                 79.89 ab  
                 3.26 ab  
                 0.00 d 
               
               
                 ‘Zentmyer’ 
                 1.50 bcd 
                 81.44 a   
                 3.19 ab  
                  0.60 bcd 
               
               
                 ‘Duke 7’ 
                 1.67 bcd 
                  32.48 abcde 
                 2.31 abcd 
                   1.11 abcd 
               
               
                 ‘Berg’ 
                 1.72 bcd 
                  46.57 abcde 
                 2.21 abcd 
                  2.00 ab 
               
               
                 ‘McKee’ 
                  1.78 abcd 
                 30.92 bcde 
                 2.24 abcd 
                  0.22 cd 
               
               
                 ‘G755A 
                  2.30 abcd 
                 19.98 de  
                 1.90 bcd 
                 0.10 d 
               
               
                 (Brokaw)’ 
                   
                   
                   
                   
               
               
                 ‘Thomas’ 
                 2.60 abc 
                 31.50 bcde 
                 2.02 abcd 
                  0.30 cd 
               
               
                 ‘UC 2023’ 
                 2.95 ab  
                 25.50 cde  
                 1.41 cd  
                 0.20 d 
               
               
                 ‘G755 A (C&amp;M)’ 
                 4.00 a  
                 15.71 e   
                 0.82 d   
                  0.00 d. 
               
               
                   
               
             
          
           
               
                   
                   
                 Tip burn 
                 Canker rating 
                 No. trees 
               
               
                   
                 Rootstock 
                 rating (0-5) 
                 (0-5) 
                 dead 
               
               
                   
               
               
                   
                 ‘Merensky II’ 
                 0.00 a 
                 0.33 a 
                 0/9  
               
               
                   
                 ‘Uzi’ 
                 0.33 a 
                 0.00 a 
                 1/10 
               
               
                   
                 ‘Steddom’ 
                 0.25 a 
                 0.00 a 
                 2/10 
               
               
                   
                 ‘Medina’ 
                 0.75 a 
                 0.00 a 
                 1/9  
               
               
                   
                 ‘Zentmyer’ 
                 0.38 a 
                 0.63 a 
                 1/10 
               
               
                   
                 ‘Duke 7’ 
                 0.38 a 
                 0.38 a 
                 3/9  
               
               
                   
                 ‘Berg’ 
                 0.17 a 
                 0.83 a 
                 3/9  
               
               
                   
                 ‘McKee’ 
                 0.43 a 
                 0.29 a 
                 2/10 
               
               
                   
                 ‘G755A (Brokaw)’ 
                 0.29 a 
                 0.14 a 
                 3/10 
               
               
                   
                 ‘Thomas’ 
                 0.17 a 
                 1.00 a 
                 4/10 
               
               
                   
                 ‘UC 2023’ 
                 0.00 a 
                 0.00 a 
                 5/10 
               
               
                   
                 ‘G755 A (C&amp;M)’ 
                 — 
                 — 
                 8/10 
               
               
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
             
           
               
                 TABLE 7 
               
             
             
               
                   
               
               
                 Tree rating August 2001 
               
             
          
           
               
                   
                 Tree rating  
                 Canopy  
                 Trunk diameter  
               
               
                 Rootstock 
                 (0-5; 5 = dead) 
                 volume (cu ft) 
                 (cm) 
               
               
                   
               
               
                 ‘Thomas’ 
                 0.00 a 
                 2.00 a 
                 22.91 a 
               
               
                 ‘Parida’ 
                 0.12 a 
                 1.08 b 
                 15.77 b 
               
               
                 ‘Steddom’ 
                 0.24 a 
                 0.95 b 
                 16.82 b 
               
               
                 ‘Spencer’ 
                 0.50 a 
                 1.84 a 
                 24.53 a 
               
               
                   
               
               
                   1 Mean values in each column followed by identical letters are not statistically different according to Waller&#39;s k-ratio t test. 
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
               
             
           
               
                 TABLE 8 
               
             
             
               
                   
               
               
                 Tree rating, July 2001 
               
             
          
           
               
                   
                   
                 Tree rating 
                 Canopy volume 
                 Trunk diameter 
               
               
                   
                 Rootstock 
                 (0-5; 5--dead) 
                 (cu ft) 
                 (cm) 
               
               
                   
                   
               
               
                   
                 ‘Steddom’ 
                 0.28 b 
                 43.22 ab 
                 2.96 a 
               
               
                   
                 ‘Thomas’ 
                 0.45 b 
                 56.76 a  
                 3.59 a 
               
               
                   
                 ‘Spencer’ 
                  1.33 ab 
                 38.58 ab 
                  2.78 ab 
               
               
                   
                 ‘Parida’ 
                 2.11 a 
                 21.42 b  
                 1.73 b 
               
               
                   
                   
               
               
                   
                   1 Mean values in each column followed by identical letters are not statistically different according to Waller&#39;s k-ratio t test. 
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 9 
               
               
                   
               
               
                 Tree rating, September 2002 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Tree rating 
                 Trunk 
                 Canopy 
                 Fruit rating 
               
               
                   
                 (0-5; 
                 diam 
                 vol 
                 (0-5; 
               
               
                 Rootstocks 
                 5 = dead) 
                 (cm) 
                 (cu ft) 
                 5-heavy) 
               
               
                   
               
               
                 ‘Steddom’ 
                 0.28 c  
                 5.58 a 
                 197.9 a 
                 1.56 a 
               
               
                 ‘Thomas’ 
                 0.64 bc 
                 6.55 a 
                 277.6 a 
                  0.73 ab 
               
               
                 ‘Spencer’ 
                 2.06 ab 
                 3.31 b 
                 105.6 b 
                 0.33 b 
               
               
                 ‘Parida’ 
                 2.39 a  
                 3.44 b 
                 102.4 b 
                 0.11 b 
               
               
                   
               
             
          
           
               
                   
                   
                 Salt rating 
                 Canker rating 
                 No. trees 
               
               
                   
                 Rootstocks 
                 (0-5; 5 = severe) 
                 (0-5; 5 =severe) 
                 dead 
               
               
                   
               
               
                   
                 ‘Steddom’ 
                 0.18 c  
                 0.00 a 
                 1/18 
               
               
                   
                 ‘Thomas’ 
                 1.05 a  
                 0.00 a 
                 1/11 
               
               
                   
                 ‘Spencer’ 
                 0.38 bc 
                 0.00 a 
                 6/18 
               
               
                   
                 ‘Parida’ 
                 0.73 ab 
                 0.62 a 
                 6/18 
               
               
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 10 
               
               
                   
               
               
                 Tree rating, August 2003. Four-ear trial to-date 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Tree rating 
                 Trunk 
                 Canopy 
                 Fruit rating 
               
               
                   
                 (0-5; 
                 diam 
                 vol 
                 (0-5; 
               
               
                 Rootstocks 
                 5 = dead) 
                 (cm) 
                 (cu ft) 
                 5-heavy) 
               
               
                   
               
               
                 ‘Steddom’ 
                 0.11 b 
                 7.79 a 
                 419.72 a 
                 1.14 a 
               
               
                 ‘Thomas’ 
                 0.82 b 
                 7.38 a 
                 417.59 a 
                  0.45 ab 
               
               
                 ‘Spencer’ 
                 2.39 a 
                 3.72 b 
                 200.02 b 
                 0.17 b 
               
               
                 ‘Parida’ 
                 2.61 a 
                 3.94 b 
                 186.14 b 
                 0.11 b 
               
               
                   
               
             
          
           
               
                   
                 Salt rating 
                 Canker rating 
                 Dead trees 
               
               
                 Rootstocks 
                 (0-5; 5 = severe) 
                 0-5; 5 = severe 
                 (%) 
               
               
                   
               
               
                 ‘Steddom’ 
                 0.39 b 
                 0.00 a 
                 0 
               
               
                 ‘Thomas’ 
                 2.05 a 
                 0.00 a 
                 9 
               
               
                 ‘Spencer’ 
                 0.55 b 
                 0.71 a 
                 41 
               
               
                 ‘Parida’ 
                 0.28 b 
                 0.40 a 
                 44 
               
               
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 11 
               
               
                   
               
               
                 Rootstock rating, December 2003. Three-year trial to-date 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Tree rating 
                 Canopy 
                 Trunk 
                 Fruit rating 
               
               
                   
                 (0-5; 
                 vol 
                 diam 
                 (0-5; 5- 
               
               
                 Rootstocks 
                 5 = dead) 
                 (cu ft) 
                 (cm) 
                 heavy) 
               
               
                   
               
               
                 ‘Zentmyer’ 
                 0.313d 
                 48.0ab 
                 6.45a 
                 1.75abc 
               
               
                 ‘Merensky II’ 
                 0.556cd 
                 71.6a 
                 6.49a 
                 2.67a 
               
               
                 ‘Steddom’ 
                 0.677bcd 
                 47.2ab 
                 5.18ab 
                 2.00ab 
               
               
                 ‘Parida’ 
                 1.147abcd 
                 50.6ab 
                 4.91ab 
                 1.53abcd 
               
               
                 ‘Evstro’ 
                 1.353abcd 
                 49.6ab 
                 5.55ab 
                 2.29ab 
               
               
                 ‘Merensky I’ 
                 1.441abcd 
                 48.6ab 
                 5.01ab 
                 1.41bcd 
               
               
                 ‘Guillemet’ 
                 1.588abc 
                 39.6b 
                 4.58b 
                 0.41d 
               
               
                 ‘Thomas’ 
                 1.875ab 
                 43.4ab 
                 4.45b 
                 0.72cd 
               
               
                 ‘UC 2023’ 
                 2.188a 
                 27.2b 
                 4.07b 
                 0.31d 
               
               
                 ‘VC 207’ 
                 2.382a 
                 32.4b 
                 3.79b 
                 1.12bcd 
               
               
                   
               
             
          
           
               
                   
                   
                 Salt rating 
                 Canker rating 
                 No. trees 
               
               
                   
                 Rootstocks 
                 (0-5; 5 = severe) 
                 (0-5; 5-severe) 
                 dead (%) 
               
               
                   
               
               
                   
                 ‘Zentmyer’ 
                 0.00a 
                 0.00a 
                 0 
               
               
                   
                 ‘Merensky II’ 
                 0.00a 
                 0.00a 
                 0 
               
               
                   
                 ‘Steddom’ 
                 0.00a 
                 0.06a 
                 6 
               
               
                   
                 ‘Parida’ 
                 0.00a 
                 0.07a 
                 18 
               
               
                   
                 ‘Evstro’ 
                 0.00a 
                 0.06a 
                 0 
               
               
                   
                 ‘Merensky I’ 
                 0.00a 
                 0.06a 
                 18 
               
               
                   
                 ‘Guillemet’ 
                 0.00a 
                 0.08a 
                 22 
               
               
                   
                 ‘Thomas’ 
                 0.00a 
                 0.08a 
                 29 
               
               
                   
                 ‘UC 2023’ 
                 0.08a 
                 0.00a 
                 19 
               
               
                   
                 ‘VC 207’ 
                 0.00a 
                 0.00a 
                 35 
               
               
                   
               
               
                 Mean values in each column followed by identical letters are not statistically different according to Waller&#39;s k-ratio t test. 
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
               
             
               
               
               
               
               
             
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 12 
               
               
                   
               
               
                 Rootstock ratings of avocado trees planted in root rot soil at 
               
               
                 Escondido, July 2002 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Tree rating 
                 Canopy 
                 Trunk 
                 Fruit set  
               
               
                   
                 0-5; 
                 volume 
                 diameter 
                 rating 0-5; 
               
               
                 Rootstocks 
                 5 = dead 
                 Cu ft 
                 Cm 
                 5 = heavy 
               
               
                   
               
               
                 ‘Zentmyer’ 
                 0.00c 
                 397.4abc 
                 7.12bcd 
                 1.53cd 
               
               
                 ‘Rio Frio’ 
                 0.00c 
                 313.5cdef 
                 6.33cdef 
                 2.13bcd 
               
               
                 ‘Merens I’ 
                 0.00c 
                 543.6a 
                 8.74a 
                 3.50a 
               
               
                 ‘Merensk II’ 
                 0.02c 
                 409.0abc 
                 7.81abc 
                 2.84ab 
               
               
                 ‘VC 241’ 
                 0.06c 
                 238.4defg 
                 6.19defg 
                 1.41cd 
               
               
                 ‘Uzi’ 
                 0.29bc 
                 504.3ab 
                 8.57ab 
                 2.76ab 
               
               
                 ‘Steddom’ 
                 0.36bc 
                 376.1bcde 
                 7.07bcd 
                 2.43bc 
               
               
                 ‘Thomas’ 
                 0.44bc 
                 388.5bcd 
                 6.75cde 
                 1.12de 
               
               
                 ‘Guillemet’ 
                 0.59bc 
                 192.0fgh 
                 4.90fgh 
                 1.12de 
               
               
                 ‘Spencer sdlg’ 
                 0.63bc 
                 225.8efg 
                 5.24efgh 
                 1.56cd 
               
               
                 ‘Leo’ 
                 0.67bc 
                 288.2cdef 
                 5.89defgh 
                 1.60cd 
               
               
                 ‘Spencer clonal’ 
                 0.69bc 
                 163.8fgh 
                 4.65gh 
                 1.54cd 
               
               
                 ‘Duke 7’ 
                 1.00b 
                 129.3gh 
                 4.38h 
                 1.47cd 
               
               
                 ‘G755A’ 
                 0.16b 
                 294.1cdef 
                 5.86defgh 
                 1.56cd 
               
               
                 ‘PolyN’ 
                 4.12a 
                 65.6h 
                 1.26i 
                 0.24e 
               
               
                   
               
             
          
           
               
                   
                   
                 Tip Burn 
                 Cankers 
                 Dead 
               
             
          
           
               
                   
                 Rootstocks 
                 Number trees affected 
               
               
                   
               
             
          
           
               
                   
                 ‘Zentmyer’ 
                 0 
                 0 
                 0/15 
               
               
                   
                 ‘Rio Frio’ 
                 0 
                 0 
                 0/16 
               
               
                   
                 ‘Merens I’ 
                 0 
                 0 
                 0/14 
               
               
                   
                 ‘Merensk II’ 
                 0 
                 1 
                 0/17 
               
               
                   
                 ‘VC 241’ 
                 0 
                 0 
                 0/16 
               
               
                   
                 ‘Uzi’ 
                 2 
                 0 
                 1/17 
               
               
                   
                 ‘Steddom’ 
                 0 
                 0 
                 1/14 
               
               
                   
                 ‘Thomas’ 
                 0 
                 0 
                 1/17 
               
               
                   
                 ‘Guillemet’ 
                 3 
                 1 
                 2/17 
               
               
                   
                 ‘Spencer sdlg’ 
                 0 
                 0 
                 2/16 
               
               
                   
                 ‘Leo’ 
                 0 
                 0 
                 2/15 
               
               
                   
                 ‘Spencer clonal’ 
                 0 
                 0 
                 5/16 
               
               
                   
                 ‘Duke 7’ 
                 0 
                 0 
                 3/15 
               
               
                   
                 ‘G755A’ 
                 2 
                 1 
                 3/16 
               
               
                   
                 ‘PolyN’ 
                 0 
                 0 
                 14/17  
               
               
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 13 
               
               
                   
               
               
                 Rootstock trial tree ratio April 2003 1 . Four-year trial to-date 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Tree rating 
                 Canopy volume 
                 Trunk diam. 
                   
               
               
                 Rootstock 
                 (0-5;5 = dead) 
                 (cu ft) 
                 (cm) 
                 Salt 
               
               
                   
               
               
                 ‘MerenI’ 
                 0.00d 
                 551ab   
                 10.7a 
                 0.08cd 
               
               
                 ‘VC241’ 
                 0.06d 
                 281efgh 
                 8.0abc 
                 0.03cd 
               
               
                 ‘Rio Frio’ 
                 0.07d 
                 362efcd 
                 8.7abc 
                 0.00d 
               
               
                 ‘Zentmyer’ 
                 0.07d 
                     410bcde 
                 9.2ab 
                 0.32bc 
               
               
                 ‘MerenII’ 
                 0.18d 
                 532abc  
                 9.4ab 
                 0.21dc 
               
               
                 ‘Spen sdlg’ 
                 0.36d 
                 263efgh 
                 6.9bc 
                 0.00d 
               
               
                 ‘Uzi’ 
                 0.38d 
                 669a   
                 10.6a 
                 0.68a 
               
               
                 ‘Steddom’ 
                 0.39d 
                 478bcd  
                 8.6abc 
                 0.32bc 
               
               
                 ‘Thomas’ 
                 0.47cd 
                 367cdef 
                 8.4abc 
                 0.62ab 
               
               
                 ‘Leo’ 
                 0.77cbd 
                 274efgh 
                 7.3abc 
                 0.13cd 
               
               
                 ‘Guillemet’ 
                 0.83cbd 
                 190ghi  
                 6.2bc 
                 0.13cd 
               
               
                 ‘Duke 7’ 
                 1.34cb 
                 127hi  
                 8.8abc 
                 0.16cd 
               
               
                 ‘Spen cl’ 
                 1.44b 
                 211fghi 
                 5.3c 
                 0.12cd 
               
               
                 ‘G755A’ 
                 1.69b 
                 322defg 
                 7.0bc 
                 0.25cd 
               
               
                 ‘PolyN’ 
                 4.15a 
                 77i  
                 1.5d 
                 0.06cd 
               
               
                   
               
             
          
           
               
                   
                   
                 Canker 
                 Fruit 
                 Dead trees 
               
               
                   
                 Rootstock 
                 (0-5; 5 = heavy) 
                 rating 2   
                 (%) 
               
               
                   
               
               
                   
                 ‘MerenI’ 
                 0a 
                 2.97abc 
                 0 
               
               
                   
                 ‘VC241’ 
                 0a 
                 3.41ab 
                 0 
               
               
                   
                 ‘Rio Frio’ 
                 0a 
                 3.73a 
                 0 
               
               
                   
                 ‘Zentmyer’ 
                 0a 
                 3.71a 
                 0 
               
               
                   
                 ‘MerenII’ 
                 0.1a   
                 2.97abc 
                 0 
               
               
                   
                 ‘Spen sdlg’ 
                 0a 
                 3.57ab 
                 7 
               
               
                   
                 ‘Uzi’ 
                 0a 
                 3.47ab 
                 6 
               
               
                   
                 ‘Steddom’ 
                 0a 
                 3.75a 
                 7 
               
               
                   
                 ‘Thomas’ 
                 0a 
                 3.53ab 
                 6 
               
               
                   
                 ‘Leo’ 
                 0a 
                 3.29ab 
                 13 
               
               
                   
                 ‘Guillemet’ 
                 0a 
                 2.90abc 
                 13 
               
               
                   
                 ‘Duke 7’ 
                 0a 
                 1.53de 
                 19 
               
               
                   
                 ‘Spen cl’ 
                 0a 
                 2.35bcd 
                 23 
               
               
                   
                 ‘G755A’ 
                 0a 
                 1.78cd 
                 25 
               
               
                   
                 ‘PolyN’ 
                 0a 
                 0.29e 
                 82 
               
               
                   
               
               
                   1 Mean values in each column followed by identical letters are not statistically different according to Waller&#39;s k-ratio t test. 
               
               
                   2 Fruit was rated in November 2003. 
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 14 
               
             
             
               
                   
               
               
                 Temecula, yield 2003 1;2 . Four year trial to-date. 
               
             
          
           
               
                   
                 Fruit weight/ 
                 Number 
                 Fruit 
               
               
                 Rootstock 
                 tree (kg) 
                 fruit/tree 
                 weight (kg) 
               
               
                   
               
             
          
           
               
                 ‘Zentmyer’ 
                 15.89a 
                 68.64a 
                 0.219a 
               
               
                 ‘Uzi’ 
                 13.99ab 
                 59.24ab 
                 0.195ab 
               
               
                 ‘Spencer seedling’ 
                 12.52ab 
                 56.27ab 
                 0.181ab 
               
               
                 ‘Merensky II’ 
                 11.83ab 
                 51.12ab 
                 0.185ab 
               
               
                 ‘Rio Frio’ 
                 10.87abc 
                 51.33ab 
                 0.187ab 
               
               
                 ‘Steddom’ 
                 10.01abc 
                 46.20abc 
                 0.175abc 
               
               
                 ‘Thomas’ 
                 8.50abcd 
                 40.12abcd 
                 0.154abc 
               
               
                 ‘G755A’ 
                 8.08abcd 
                 34.56abcd 
                 0.116bc 
               
               
                 ‘VC241’ 
                 7.44bcd 
                 31.75bcd 
                 0.202ab 
               
               
                 ‘Guillemet’ 
                 7.42bcd 
                 30.00bcd 
                 0.196ab 
               
               
                 ‘Spencer clonal’ 
                 6.99bcd 
                 32.00bcd 
                 0.136abc 
               
               
                 ‘Merensky I’ 
                 6.95bcd 
                 32.08bcd 
                 0.148abc 
               
               
                 ‘Leo’ 
                 6.53bcd 
                 28.14bcd 
                 0.140abc 
               
               
                 ‘Duke 7’ 
                 3.33cd 
                 14.81cd 
                 0.138abc 
               
               
                 ‘PolyN’ 
                 1.72d 
                 5.71d 
                 0.076c 
               
               
                   
               
               
                   1 Mean values in each column followed by identical letters are not statistically different according to Waller&#39;s k-ratio t test. 
               
               
                   2 Only fruit which were grade size were picked; remaining fruit on trees to be picked later. 
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 15 
               
             
             
               
                   
               
               
                 Tree rating February 2002 1   
               
             
          
           
               
                   
                 Tree rating 
                 Fruit set 
                 Canopy 
                 Trunk 
                 No.  
               
               
                   
                 (0-5; 
                 rating (0-5; 
                 volume 
                 diameter 
                 trees 
               
               
                 Rootstocks 
                 5 = dead) 
                 5 = heavy) 
                 (cu ft) 
                 (cm) 
                 dead 
               
               
                   
               
               
                 ‘Parida’ 
                 1.00 b 
                 0.00 a 
                 13.63 a 
                 2.37 a 
                 0 
               
               
                 ‘Steddom’ 
                 1.30 b 
                 0.10 a 
                 18.46 a 
                 2.54 a 
                 0 
               
               
                 ‘Afek’ 
                  1.50 ab 
                 0.00 a 
                 21.16 a 
                 2.59 a 
                 0 
               
               
                 ‘Thomas’ 
                 2.13 a 
                 0.05 a 
                 15.90 a 
                 2.41 a 
                 1 
               
               
                   
               
               
                   1 Mean values in each column followed by identical letters are not statistically different according to Waller&#39;s k-ratio t test 
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                 TABLE 16 
               
             
             
               
                   
               
               
                 Tree rating, March 2003 1 . Two-year trial to-date. 
               
             
          
           
               
                   
                 Tree rating 
                 Canopy 
                 Trunk 
                 Salt tip 
                 Canker 
                 Dead 
               
               
                   
                 (0-5; = 
                 vol 
                 diam 
                 0-5;5 = 
                 (0-5;5 = 
                 trees 
               
               
                 Rootstock 
                 dead) 
                 (cu ft) 
                 (cm) 
                 severe) 
                 severe 
                 (%) 
               
               
                   
               
             
          
           
               
                 ‘Steddom’ 
                 0.92 a 
                 61.93 a 
                 4.25 ab 
                 0.61 b 
                 0.00 a 
                 5 
               
               
                 ‘Afek’ 
                 1.08 a 
                 72.04 a 
                 4.85 a  
                 1.50 a 
                 0.33 a 
                 0 
               
               
                 ‘Parida’ 
                 1.30 a 
                 44.31 a 
                 3.91 ab 
                 0.47 b 
                 0.44 a 
                 10 
               
               
                 ‘Thomas’ 
                 1.95 a 
                 39.86 a 
                 3.43 b  
                 1.85 a 
                 0.47 a 
                 15 
               
               
                   
               
               
                   1 Mean values in each column followed by identical letters are not statistically different according to Waller&#39;s k-ratio t test 
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
               
               
               
             
           
               
                 TABLE 17 
               
             
             
               
                   
               
               
                 Escondido, Tree ratings, July 2002 
               
             
          
           
               
                   
                 Tree rating 
                 Canopy 
                 Trunk 
                 No. 
                 No. trees 
                   
               
               
                   
                 (0-5; 
                 vol. 
                 diam 
                 trees 
                 w/tip 
                 No. trees 
               
               
                 Rootstock 
                 5 = dead) 
                 (cu ft) 
                 (cm) 
                 Dead 
                 burn 
                 w/canker 
               
               
                   
               
               
                 ‘Uzi’ 
                 0.039 b 
                 34.69 a 
                 2.43 a 
                 0 
                 6 
                 0 
               
               
                 ‘Guillemet’ 
                 0.042 b 
                 22.86 a 
                 2.06 a 
                 0 
                 4 
                 0 
               
               
                 ‘Zentmyer’ 
                 0.077 b 
                 22.40 a 
                 2.25 a 
                 0 
                 2 
                 0 
               
               
                 ‘Spencer sdlg’ 
                 0.536 b 
                 27.81 a 
                 2.01 a 
                 0 
                 2 
                 1 
               
               
                 ‘Steddom’ 
                 0.615 b 
                 18.93 a 
                 1.99 a 
                 1 
                 0 
                 0 
               
               
                 ‘Berg’ 
                 0.714 b 
                 21.42 a 
                 1.98 a 
                 0 
                 1 
                 2 
               
               
                 ‘Merensky II’ 
                 0.750 b 
                 32.07 a 
                 2.10 a 
                 2 
                 0 
                 1 
               
               
                 ‘Elinor’ 
                 0.786 b 
                 29.44 a 
                 2.03 a 
                 1 
                 0 
                 2 
               
               
                 ‘Thomas’ 
                 0.846 b 
                 23.07 a 
                 1.85 a 
                 1 
                 2 
                 0 
               
               
                 ‘Pond’ 
                  1.00 ab 
                 30.55 a 
                 2.15 a 
                 1 
                 0 
                 2 
               
               
                 ‘Crowley’ 
                 1.083 ab 
                 23.78 a 
                 1.86 a 
                 2 
                 1 
                 0 
               
               
                 ‘G755A’ 
                 1.231 ab 
                 22.64 a 
                 1.85 a 
                 2 
                 0 
                 0 
               
               
                 ‘Duke 9’ 
                 2.270 a  
                  9.40 a 
                 1.07 b 
                 5 
                 0 
                 0 
               
               
                   
               
               
                 There were significant differences at P = 0.01 between blocks for all tree parameters analyzed. 
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
               
             
               
               
               
               
               
               
               
             
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 18 
               
               
                   
               
               
                 Tree ratings, April 2003. Two-year trial to-date. 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Tree rating 
                 Canopy 
                 Trunk 
                 Fruit rating 
               
               
                   
                 (0-5; 
                 vol 
                 diam 
                 (0-5; 
               
               
                 Rootstock 
                 5 = dead) 
                 (cu ft) 
                 (cm) 
                 5 = heavy) 
               
               
                   
               
             
          
           
               
                 ‘Uzi’ 
                 0.267  
                 c 
                 88.76 a 
                 4.193  
                 a 
                 0.0 a 
               
               
                 ‘Berg’ 
                 0.531  
                 c 
                 44.16 a 
                 2.956  
                 bc 
                 0.0 a 
               
               
                 ‘Zentmyer’ 
                 0.600  
                 c 
                 54.37 a 
                 3.393  
                 ab 
                 0.0 a 
               
               
                 ‘Merensky II’ 
                 0.833  
                 bc 
                 68.49 a 
                 3.333  
                 ab 
                 0.0 a 
               
               
                 ‘Steddom’ 
                 0.867  
                 bc 
                 56.42 a 
                 3.127  
                 ab 
                 0.0 a 
               
               
                 ‘Pond’ 
                 0.906  
                 bc 
                 55.05 a 
                 3.188  
                 ab 
                 0.0 a 
               
               
                 ‘Spenser 
                 0.906  
                 bc 
                 51.45 a 
                 2.988  
                 bc 
                 0.0 a 
               
               
                 sdlg’ 
                   
                   
                   
                   
                   
                   
               
               
                 ‘Crowley’ 
                 0.964  
                 bc 
                 42.05 a 
                 3.021  
                 bc 
                 0.0 a 
               
               
                 ‘Thomas’ 
                 1.071  
                 bc 
                 49.99 a 
                 2.900  
                 bc 
                 0.0 a 
               
               
                 ‘Guillemet’ 
                 0.167  
                 abc 
                 43.64 a 
                 2.960  
                 bc 
                 0.1 a 
               
               
                 ‘Elinor’ 
                 1.393  
                 abc 
                 58.40 a 
                 2.864  
                 bc 
                 0.0 a 
               
               
                 ‘G755A’ 
                 2.156  
                 ab 
                 44.21 a 
                 2.819  
                 bc 
                 0.0 a 
               
               
                 ‘Duke 9’ 
                 2.577  
                 a 
                 32.16 a 
                 1.885  
                 c 
                 0.0 a 
               
               
                   
               
             
          
           
               
                   
                   
                 Salt rating 
                 Canker rating 
                   
               
               
                   
                   
                 (0-5; 
                 (0-5;5 = 
                 No. trees 
               
               
                   
                 Rootstock 
                 5 = severe) 
                 severe)  
                 Dead (%) 
               
               
                   
               
             
          
           
               
                   
                 ‘Uzi’ 
                 0.933  
                 ab 
                 0.000 a 
                 0 
               
               
                   
                 ‘Berg’ 
                 0.633  
                 abcd 
                 0.000 a 
                 6 
               
               
                   
                 ‘Zentmyer’ 
                 1.000  
                 a 
                 0.000 a 
                 7 
               
               
                   
                 ‘Merensky II’ 
                 0.154  
                 cd 
                 0.308 a 
                 13 
               
               
                   
                 ‘Steddom’ 
                 0.321  
                 bcd 
                 0.286 a 
                 7 
               
               
                   
                 ‘Pond’ 
                 0.767  
                 abc 
                 0.200 a 
                 6 
               
               
                   
                 ‘Spenser sdlg’ 
                 0.300  
                 bcd 
                 0.200 a 
                 6 
               
               
                   
                 ‘Crowley’ 
                 0.083  
                 d 
                 0.000 a 
                 14 
               
               
                   
                 ‘Thomas’ 
                 0.731  
                 abc 
                 0.000 a 
                 0 
               
               
                   
                 ‘Guillemet’ 
                 0.615  
                 abcd 
                 0.133 a 
                 13 
               
               
                   
                 ‘Elinor’ 
                 0.333  
                 bcd 
                 0.167 a 
                 14 
               
               
                   
                 ‘G755A’ 
                 0.846  
                 ab 
                 0.077 a 
                 13 
               
               
                   
                 ‘Duke 9’ 
                 0.313  
                 bcd 
                 0.500 a 
                 38 
               
               
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
               
             
               
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 19 
               
               
                   
               
               
                 Santa Paula, rootstock rating, December 2002 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Tree rating 
                 Canopy vol 
                 Trunk diam 
                 Fruit 
               
               
                 Rootstock 
                 (0-5; 5 = dead) 
                 (cu ft) 
                 (cm) 
                 set 
               
               
                   
               
             
          
           
               
                 ‘McKee’ 
                 0.00 b 
                 51.41 a 
                 3.45  
                 bc 
                 0.00 a 
               
               
                 ‘Merensky II’ 
                 0.00 b 
                 53.45 a 
                 3.66  
                 ab 
                 0.00 a 
               
               
                 ‘Pond’ 
                 0.00 b 
                 55.08 a 
                 3.69  
                 a 
                 0.00 a 
               
               
                 ‘Guillemet’ 
                 0.00 b 
                 37.98 b 
                 2.71  
                 f 
                 0.00 a 
               
               
                 ‘Zentmyer’ 
                 0.00 b 
                 51.92 a 
                 3.38  
                 cd 
                 0.00 a 
               
               
                 ‘Thomas’ 
                 0.00 b 
                 36.66 b 
                 3.15  
                 de 
                 0.00 a 
               
               
                 ‘Crowley’ 
                 0.03 b 
                 34.91 b 
                 3.17  
                 d 
                 0.05 a 
               
               
                 ‘Duke 9’ 
                 0.05 b 
                 31.93 b 
                 2.93  
                 ef 
                 0.00 a 
               
               
                 ‘Steddom’ 
                 0.27 a 
                 37.14 b 
                 2.75  
                 f 
                 0.00 a 
               
               
                   
               
             
          
           
               
                   
                   
                 Salt burn 
                   
                 Trees dead 
               
               
                   
                 Rootstock 
                 (0-5; 5-heavy) 
                 Cankers 
                 (%) 
               
               
                   
               
               
                   
                 ‘McKee’ 
                 0 
                 0 
                 0 
               
               
                   
                 ‘Merensky II’ 
                 0 
                 0 
                 0 
               
               
                   
                 ‘Pond’ 
                 0 
                 0 
                 0 
               
               
                   
                 ‘Guillemet’ 
                 0 
                 0 
                 0 
               
               
                   
                 ‘Zentmyer’ 
                 0 
                 0 
                 0 
               
               
                   
                 ‘Thomas’ 
                 0 
                 0 
                 0 
               
               
                   
                 ‘Crowley’ 
                 0 
                 0 
                 0 
               
               
                   
                 ‘Duke 9’ 
                 0 
                 0 
                 0 
               
               
                   
                 ‘Steddom’ 
                 0 
                 0 
                 0 
               
               
                   
               
               
                 Mean values in each column followed by identical letters are not statistically different according to Waller&#39;s k-ratio. 
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 20 
               
               
                   
               
               
                 Santa Paula, rootstock rating, December 2003. Two-year trial to-date 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                   
                 Canopy 
                 Trunk 
                 Fruit rating 
               
               
                   
                 Tree rating 
                 vol 
                 diam 
                 (0-5; 
               
               
                 Rootstock 
                 (0-5; 5 = dead) 
                 (cu ft) 
                 (cm) 
                 5 = heavy) 
               
               
                   
               
               
                 ‘McKee’ 
                 0.025b 
                 184.1b 
                 5.88bc 
                 1.90ab 
               
               
                 ‘Merensky II’ 
                 0.000b 
                 246.8a 
                  6.18abc 
                 2.60a  
               
               
                 ‘Pond’ 
                 0.000b 
                 192.0b 
                 6.24ab 
                 0.00d  
               
               
                 ‘Guillemet’ 
                 0.000b 
                  118.8cd 
                 5.38de 
                 0.00d  
               
               
                 ‘Zentmyer’ 
                 0.026b 
                 182.8b 
                 6.41a  
                 1.32bc 
               
               
                 ‘Thomas’ 
                 0.237a 
                 174.9b 
                 5.72cd 
                 0.47cd 
               
               
                 ‘Crowley’ 
                  0.150ab 
                 124.7c 
                 5.42de 
                 2.15ab 
               
               
                 ‘Duke 9’ 
                  0.053ab 
                 132.6c 
                 5.19e  
                 1.89ab 
               
               
                 ‘Steddom’ 
                  0.083ab 
                  86.3d 
                 5.00e  
                 2.00ab 
               
               
                   
               
             
          
           
               
                   
                   
                 Salt burn 
                   
                 Trees dead 
               
               
                   
                 Rootstock 
                 (0-5; 5-heavy) 
                 Cankers 
                 (%) 
               
               
                   
               
               
                   
                 ‘McKee’ 
                 0 
                 0 
                 0 
               
               
                   
                 ‘Merensky II’ 
                 0 
                 0 
                 0 
               
               
                   
                 ‘Pond’ 
                 0 
                 0 
                 0 
               
               
                   
                 ‘Guillemet’ 
                 0 
                 0 
                 0 
               
               
                   
                 ‘Zentmyer’ 
                 0 
                 0 
                 0 
               
               
                   
                 ‘Thomas’ 
                 0 
                 0 
                 0 
               
               
                   
                 ‘Crowley’ 
                 0 
                 0 
                 0 
               
               
                   
                 ‘Duke 9’ 
                 0 
                 0 
                 0 
               
               
                   
                 ‘Steddom’ 
                 0 
                 0 
                 0 
               
               
                   
               
               
                 Mean values in each column followed by identical letters are not statistically different according to Waller&#39;s k-ratio t test. 
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 21 
               
               
                   
               
               
                 Temecula rootstock ratings, Sept 2002 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Tree rating 
                 Canopy 
                 Trunk 
                 Fruit rating 
               
               
                   
                 (0-5; 
                 vol. 
                 diam 
                 (0-5; 
               
               
                 Rootstock 
                 5 = dead) 
                 (cu ft) 
                 (cm) 
                 5 = heavy) 
               
               
                   
               
             
          
           
               
                 ‘Zentmyer’ 
                 0.400 
                 c 
                 40.70 
                 ab 
                 2.79 
                 a 
                 0.00 b 
               
               
                 ‘Crowley’ 
                 0.618 
                 c 
                 40.38 
                 ab 
                 2.86 
                 a 
                 0.00 b 
               
               
                 ‘Elinor’ 
                 0.824 
                 c 
                 40.52 
                 ab 
                 2.54 
                 a 
                 0.00 b 
               
               
                 ‘Guillemet’ 
                 0.882 
                 bc 
                 39.13 
                 ab 
                 2.42 
                 a 
                 0.00 b 
               
               
                 ‘Steddom’ 
                 0.969 
                 bc 
                 29.20 
                 bc 
                 2.13 
                 ab 
                 1.16 a 
               
               
                 ‘Thomas’ 
                 0.969 
                 bc 
                 31.46 
                 bc  
                 2.13 
                 ab 
                 0.00 b 
               
               
                 ‘Pond’ 
                 1.088 
                 bc 
                 54.08 
                 a 
                 2.78 
                 a 
                 0.00 b 
               
               
                 ‘Uzi’ 
                 1.188 
                 bc 
                 35.08 
                 ab 
                 2.56 
                 a 
                 0.00 b 
               
               
                 ‘G755A’ 
                 2.088 
                 ab 
                 37.85 
                 ab 
                 2.41 
                 a 
                 0.00 b 
               
               
                 ‘Spencer 
                 2.906 
                 a 
                 11.96 
                 c 
                 1.39 
                 b 
                 0.00 b 
               
               
                 sdlg’ 
               
               
                   
               
             
          
           
               
                   
                   
                 Salt damage 
                 Cankers 
                 No. trees 
               
               
                   
                 Rootstock 
                 (0-5; 5 = heavy) 
                 (0-5; 5 = heavy) 
                 dead 
               
               
                   
               
             
          
           
               
                   
                 ‘Zentmyer’ 
                 1.50  
                 ab 
                 0.00 a 
                 0/15 
               
               
                   
                 ‘Crowley’ 
                 1.34 
                 b 
                 0.00 a 
                 1/17 
               
               
                   
                 ‘Elinor’ 
                 1.59  
                 ab 
                 0.00 a 
                 1/17 
               
               
                   
                 ‘Guillemet’ 
                 1.41 
                 b 
                 0.00 a 
                 2/17 
               
               
                   
                 ‘Steddom’ 
                 1.54  
                 ab 
                 0.50 a 
                 2/16 
               
               
                   
                 ‘Thomas’ 
                 1.50  
                 ab 
                 0.00 a 
                 3/16 
               
               
                   
                 ‘Pond’ 
                 1.40 
                 b 
                 0.00 a 
                 2/17 
               
               
                   
                 ‘Uzi’ 
                 1.64  
                 ab 
                 0.00 a 
                 2/16 
               
               
                   
                 ‘G755A’ 
                 2.50  
                 ab 
                 0.36 a 
                 4/17 
               
               
                   
                 ‘Spencer sdlg’ 
                 2.63 
                 a 
                 0.00 a 
                 4/16 
               
               
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 22 
               
               
                   
               
               
                 Temecula, rootstock ratings, December 2003. Two-year trial to-date 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Tree rating 
                 Canopy 
                 Trunk 
                 Fruit rating 
               
               
                   
                 (0-5; 
                 vol 
                 diam 
                 (0-5; 
               
               
                 Rootstock 
                 5 = dead) 
                 (cu ft) 
                 (cm) 
                 5 = heavy) 
               
               
                   
               
               
                 ‘Zentmyer’ 
                 0.313c  
                 207.27a 
                 6.23a 
                 2.063a 
               
               
                 ‘Pond’ 
                 0.906c  
                 307.04a 
                 5.75a 
                 1.813a 
               
               
                 ‘Elinor’ 
                 0.912c  
                 170.37a 
                  4.80a. 
                 1.059a 
               
               
                 ‘Guillemet’ 
                 1.059c  
                 199.37a 
                 5.73a 
                 0.882a 
               
               
                 ‘Uzi’ 
                 1.094bc 
                 206.04a 
                 4.35a 
                 0.813a 
               
               
                 ‘Crowley’ 
                 1.250bc 
                 144.14a 
                 5.04a 
                 1.438a 
               
               
                 ‘Steddom’ 
                 1.281bc 
                 254.94a 
                 4.89a 
                 1.188a 
               
               
                 ‘Thomas’ 
                 1.313bc 
                 226.39a 
                 5.16a 
                 1.375a 
               
               
                 ‘G755A’ 
                 2.438ab 
                 175.55a 
                 5.23a 
                 0.625a 
               
               
                 ‘Spencer sdlg’ 
                 2.813a  
                  42.12a 
                 2.26a 
                 0.519a 
               
               
                   
               
             
          
           
               
                   
                   
                 Salt damage 
                 Cankers 
                 Trees dead 
               
               
                   
                 Rootstock 
                 (0-5; 5 = heavy) 
                 (0-5; 5 = heavy) 
                 (%) 
               
               
                   
               
               
                   
                 ‘Zentmyer’ 
                 1.188ab 
                 0.000a 
                 0 
               
               
                   
                 ‘Pond’ 
                 0.321cd 
                 0.000a 
                 13 
               
               
                   
                 ‘Elinor’ 
                 0.469cd 
                 0.000a 
                 6 
               
               
                   
                 ‘Guillemet’ 
                  0.893abc 
                 0.000a 
                 18 
               
               
                   
                 ‘Uzi’ 
                  0.769abcd 
                 0.000a 
                 19 
               
               
                   
                 ‘Crowley’ 
                  0.731abcd 
                 0.000a 
                 19 
               
               
                   
                 ‘Steddom’ 
                 0.167d  
                 0.000a 
                 25 
               
               
                   
                 ‘Thomas’ 
                 1.308a  
                 0.000a 
                 19 
               
               
                   
                 ‘G755A’ 
                 1.167ab 
                 0.000a 
                 25 
               
               
                   
                 ‘Spencer sdlg’ 
                  0.500bcd 
                 0.000a 
                 44 
               
               
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 23 
               
               
                   
               
               
                 Rootstock rating, December 2003. On-Year trial to-date 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                   
                 Trunk 
                 Canopy 
                   
               
               
                   
                 Tree rating 
                 diam 
                 vol 
                 Fruit rating 
               
               
                 Rootstocks 
                 (0-5; 5 = dead) 
                 (cm) 
                 (cu ft) 
                 (0-5; 5-heavy) 
               
               
                   
               
               
                 ‘Steddom’ 
                 0.050b 
                 3.171a 
                 47.54a 
                 1.353a 
               
               
                 ‘VC801’ 
                 1.750a 
                 2.628a 
                 38.08a 
                 0.556a 
               
               
                 ‘Thomas’ 
                 2.688a 
                 1.800b 
                 17.35b 
                 0.063a 
               
               
                   
               
             
          
           
               
                   
                   
                 Salt ratin 
                 Canker rating 
                 No. trees 
               
               
                   
                 Rootstocks 
                 (0-5; 5 = severe) 
                 (0-5; 5 = severe) 
                 dead (%) 
               
               
                   
               
               
                   
                 ‘Steddom’ 
                 0.088a 
                 0.000a 
                 0 
               
               
                   
                 ‘VC801’ 
                 0.000a 
                 0.000a 
                 38 
               
               
                   
                 ‘Thomas’ 
                 0.100a 
                 0.000a 
                 11 
               
               
                   
               
               
                 Mean values in each column followed by identical letters are not statistically different according to Waller&#39;s k-ratio t test.