Patent Publication Number: US-8660-P

Title: Strawberry plant called &#34;Carlsbad&#34;

Description:
DESCRIPTION 
     This invention relates to a new and distinctive short-day type cultivar designated as `Carlsbad`, which resulted from a cross performed in 1988 between the cultivar `Irvine` (U.S. Plant Pat. No. 7,172) and advanced selection Cal 85.218-605. 
     `Carlsbad` was first fruited at the University of California South Coast Research and Extension Center, near Irvine, Calif. in 1989, where it was selected, originally designated Cal 88.70-613, and propagated asexually by runners. Asexual propagules from this original source have been tested at the South Coast Research and Extension Center, the Watsonville Strawberry Research Facility, and to a limited extent in grower fields starting in 1990. 
    
    
     FIG. 1 shows the general flowering and fruiting characteristics of the plant; 
     FIG. 2 shows a typical mature leaf during late spring; and 
     FIG. 3 shows representative mid-season fruit. 
    
    
     `Carlsbad` is typical of short-day types and products fruit over an extended period when treated appropriately in arid, subtropical climates. `Carlsbad` differs from `Irvine` in that `Irvine` is a day-neutral type with essentially no photoperiodic flowering response and as compared with `Carlsbad` is more difficult to grow. The production pattern for `Carlsbad` is similar to that for `Chandler`, although it produces substantially greater quantities of early-season fruit. `Carlsbad` will be of special interest for winter plantings, where `Chandler` has been successful, and in summer plantings where `Pajaro` has been successful. 
     Plants and foliage: Fruiting plants of `Carlsbad` are larger, more erect, and more vigorous than plants of `Chandler` (U.S. Plant Pat. No. 5,262), and are generally similar in form to plants of `Oso Grande` (U.S. Plant Pat. No. 6,578). `Carlsbad` forms branch crowns in greater quantity than `Chandler` with similar branching to `Oso Grande`. When propagated in the nursery, `Carlsbad` has similar or greater runner production capacity compared with `Chandler`. Comparative statistics for foliar characters, including leaf color, near mid-season are given for the three cultivars in Table 1 with visual comparisons of leaf color according to the Munsell color scale (Nickerson Color Fan) given in Table 5. Leaf color is distinctly lighter on the underside for `Carlsbad`; the differential is larger than for `Chandler` and similar to that for `Oso Grande`. Individual leaflets for `Carlsbad` are larger and somewhat more elongated than `Chandler`, and are less rounded than for `Oso Grande`. Leaves (including petioles) are longer and much broader than for `Chandler`. Petioles are thicker and stiffer than those of `Chandler` and are similar to those of `Oso Grande`. Paired stipules, borne in a median position on the petiole, appear as small, stalked, ovate to heart-shaped structures on most leaves for `Carlsbad` and the comparison cultivars. Stipule size varies greatly both within and among individual plants for `Carlsbad`, and one or both stipules may be absent or may be abscise as the leaf matures. Leaf and petiole pubescence characters for `Carlsbad` are similar to those for `Oso Grande`, except that tomentum on leaves are less dense. Also, leaves for `Carlsbad` are darker than leaves of `Chandler` and similar in color but slightly darker than those of `Oso Grande`. Visual comparisons of fruit color according to the Munsel color scale (Nickerson Color Fan) are given in Table 5. `Carlsbad` has flat (occasionally concave) leaves, which are easily distinguished from ` Chandler`, and are similar in convexity to `Oso Grande`. 
     Isozymes in leaf extracts: `Carlsbad` has been classified for three isozyme systems using starch gel electrophoresis (Table 2): Phosophoglucoisomerase (PGI), Leucine Aminopeptidase (LAP), and Phosphoglucomutase (PGM). It is distinguishable from all other short-day cultivars released to date. For electrophoretic procedures see: J. Amer. Soc. Hort. Sci. 106:684-687. 
     Disease and pest reaction: `Carlsbad` is moderately resistant to common leaf spot (Ramularia tulasnei) and powdery mildew (Sphaerotheca macularis). When treated properly, it has equal or greater tolerance to two-spotted spidermites (Tetranychus urticae) than `Chandler`. `Carlsbad` is tolerant to strawberry viruses encountered in California. 
     
                       TABLE 1                                                     
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Foliar characteristics for                                                
`Carlsbad`, `Chandler`, and `Oso Grande`.                                 
          Cultivar                                                        
Foliar Character                                                          
            `Carlsbad` `Chandler` `Oso Grande`                            
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Mid-tier leaflet                                                          
Length (mm)                                                               
mean        90.4       82.4       77.2                                    
range       85-97      78-94      75-80                                   
Width (mm)                                                                
mean        75.8       71.4       67.6                                    
range       65-82      63-88      62-71                                   
Mid-tier leaf                                                             
Length (mm)                                                               
mean        261.0      244.2      191.6                                   
range       257-269    218-262    170-200                                 
Width (mm)                                                                
mean        162.4      148.0      137.2                                   
range       148-175    132-158    130-149                                 
Leaf color                                                                
(CIELAB)*                                                                 
L*                                                                        
mean        30.0       31.4       31.9                                    
range       27.7-31.8  27.1-33.3  29.9-33.0                               
a*                                                                        
mean        -6.7       -8.0       -5.3                                    
range       -3.8--8.8  -5.2--8.2  -4.2--8.3                               
b*                                                                        
mean        14.2       16.0       15.5                                    
range       10.0-17.5  12.9-21.4  12.5-20.6                               
# leaflets/leaf                                                           
            3          3          3                                       
Leaf convexity                                                            
            flat/slight                                                   
                       concave    concave                                 
            concave                                                       
Serrations                                                                
number      few        many       moderate                                
shape       semi-round semi-pointed                                       
                                  semi-round                              
Leaf pubescence                                                           
            moderate   moderate/  moderate/                               
                       sparse     heavy                                   
Petiole pubescence                                                        
density     heavy      heavy      heavy                                   
direction   perpendicular                                                 
                       acropetal  perpendicular                           
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 *CIELAB is the abbreviation of the international color system known as   
 &#34;Commission Internationale De L&#39;Eclairage&#34; 1978. Recommendations on      
 uniform color spaces -- color difference equations, psychometric color   
 terms, Supplement No. 2 to CIE Publication No. 15. PARIS. 2              
 
    
     
                       TABLE 2                                                     
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Isozyme phenotypes for `Carlsbad`, `Chandler`, and `Oso Grande`.          
Cultivar                                                                  
Locus   `Carlsbad`   `Chandler`                                           
                               `Oso Grande`                               
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PGI     A2           A1        A2                                         
LAP     B3           B3        B3                                         
PGM     C1           C1        C2                                         
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     Flowering, fruiting, fruit, and production characteristics: Comparative statistics for flower and fruit characters, including fruit color, near mid-season are given for `Carlsbad`, `Chandler` and `Oso Grande` in Table 3. The primary flowers for `Carlsbad` are slightly larger than those of `Chandler` and `Oso Grande`, whereas the sepals are substantially larger than for the comparison cultivars. Each primary flower has 5-7 petals. The calyx for `Carlsbad` is usually even with the shoulder of the fruit, but is occasionally slightly indented and ocassionally necked. The primary fruit shape for `Carlsbad` is a very flat conic, with secondary fruit usually a blocky conic. External fruit color for `Carlsbad`, is lighter than `Chandler`, and `Oso Grande`. and the fruit somewhat less glossy than `Chandler`; internal color is lighter than `Chandler` and darker than for `Oso Grande`. Achenes vary from yellow to dark red, and are even with the fruit surface or slightly extruded. 
     `Carlsbad` has been tested under a variety of cultural regimes, and optimal performance is obtained when nursery treatments, pre-plant chilling regimes, plant densities, and nutritional programs similar to those that optimize performance for `Chandler` are used. In general, `Carlsbad` is more adapted to early-season planting with less supplemental chilling than `Chandler`. 
     When treated with appropriate planting regimes, `Carlsbad` has larger fruit and produces greater yields than `Chandler` or `Oso Grande` (Table 4). `Carlsbad` is similar to `Chandler` and `Oso Grande` in its production pattern, although it produces substantially more early-season fruit than either cultivar (with conventional winter planting). Commercial appearance ratings have been comparable to or better than those for `Chandler`. Fruit of `Carlsbad` is firmer than that for `Chandler`; `Carlsbad` is about as firm as `Oso Grande`. Subjectively, `Carlsbad` has very good flavor, somewhat less aromatic than `Chandler`, but with better acid balance and more aromatic components than `Oso Grande`. The fruit will be outstanding for both fresh market and processing, due to its firm flesh and relatively dark internal color, and will be useful for home garden purposes. 
     
                       TABLE 3                                                     
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Flower and fruit characters for                                           
`Carlsbad`, `Chandler`, and `Oso Grande`.                                 
            Cultivar                                                      
Character     `Carlsbad`                                                  
                        `Chandler`                                        
                                  `Oso Grande`                            
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# petals                                                                  
mean           6.2       6.6       5.0                                    
range         5-7       6-8       5-5                                     
Flower position                                                           
              exposed   even/     exposed                                 
(relative to foliage)   exposed                                           
Calyx diam. (mm)                                                          
mean          63.8      47.7      34.1                                    
range         56-70     45-53     27-38                                   
Corolla diam. (mm)                                                        
mean          40.7      39.3      32.2                                    
range         37-44     36-46     27-41                                   
Fruit shape                                                               
length/width   1.02      1.33      1.06                                   
ratio                                                                     
subjective    flat/conic                                                  
                        flat conic                                        
                                  blocky/conic                            
Calyx position                                                            
              even/slight                                                 
                        even/slight                                       
                                  even/slight                             
              indent    neck      indent                                  
Seed position slight    even/slight                                       
                                  even                                    
              extrude   indent                                            
Fruit color (CIELAB)                                                      
external                                                                  
L*            25.4      23.6      22.4                                    
a*            29.9      38.5      31.2                                    
b*            16.3      14.8      17.2                                    
internal                                                                  
L*            47.8      46.2      54.1                                    
a*            37.9      39.1      30.4                                    
b*            28.9      29.4      22.7                                    
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                       TABLE 4                                                     
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Performance for selection `Carlsbad` compared with `Oso Grande`           
and `Chandler` at the South Coast Research and Extension Center           
in 1991. All plants were dug from the South Coast nursery on              
October 1 and planted October 2 (68&#34;/4-row beds, 23,061                   
plants/A, 100 g/plant = 425 Crates/A).                                    
         Yield    Total           Appear-                                 
         To 4/1   Yield    Size   ance   Firm-                            
         (g/plant)                                                        
                  (g/plant)                                               
                           (g/fruit)                                      
                                  Score  ness                             
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`Carlsbad`                                                                
         510      2,308    27.2   4.2    4.7                              
`Chandler`                                                                
         463      1,738    23.3   3.9    4.0                              
`Oso Grande`                                                              
         530      1,675    25.0   3.8    4.9                              
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                       TABLE 5                                                     
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Munsell color classification for leaf and fruit characters.               
Munsell                  Munsell                                          
Leaf Color Classes       Fruit Color Classes                              
       Upper      Lower                                                   
Item   (Adaxial)  (Abaxial)  External                                     
                                     Internal                             
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Chandler                                                                  
       5GY 4/3    5GY 5/6    5R 5/13 7R 5/13                              
       5GY 5/6               5R 4/12                                      
Oso    5GY 4/3    5GY 5/6    5R 5/13 7.5R 7/9                             
       5GY 3/2    7.5GY 6/8  7.5R 5/13                                    
                                     7.5R 6/12                            
Carlsbad                                                                  
       7.5GY 4/4  7.5GY 5/8  7.5R 5/13                                    
                                     7.5R 6/12                            
       5GY 4/3    7.5GY 4/7  7.5R 4/11                                    
                                     7.5R 5/13                            
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