Literature Cited

Ahmad, M. and I. Khan. 1987. Effect of waxing and cellophane lining on

chemical quality indices of citrus fruit. Plant Foods for Human Nutrition

37:47-57.

Beyer, W. H. 1988. CRC handbook of tables for probability and statistics. 2nd

ed. CRC Press, Inc. Boca Raton, FL.

Davis, P. L. 1970. Relation of ethanol content of citrus fruits to maturity and

to storage conditions. Proc. Fla. State Hort. Soc. 83:294-298.

Davis, P. L. and R. C. Hofmann. 1973. Effects of coatings on weight loss and

ethanol buildup in juice of oranges. J. Agr. Food Chem. 21(3) 455-458.

Hagenmaier, R. D. and R. A. Baker. 1993. Citrus fruit with single or layered

coatings compared with packinghouse-coated fruit. Proc. Fla. State Hort.

Soc. 106:238-240.

Hagenmaier, R. D. and R. A. Baker. 1994. Wax microemulsions and emul

sions as citrus coatings. J. Agr. Food Chem. 42(4):899-902.

Hasegawa, Y. and Y. Iba. 1980. The effects of coating with wax on citrus fruit.

Bulletin Fruit Tree Rsch. Sta., Series B., 7:85-97.

Ke, D. and A. A. Kader, 1990. Tolerance of'Valencia' oranges to controlled

atmospheres as determined by physiological responses and quality at

tributes. J. Amer. Soc. Hort. Sci. 115(5):79-783.

Prussia, S. E. and R. L. Shewfelt. 1993. Systems approach to postharvest han

dling, p. 43-71. in R. L. Shewfelt and S. E. Prussia (eds.) Postharvest han

dling, a systems approach, Academic press, San Diego, Calif.

Proc. Fla. State Hort. Soc. 107: 265-269. 1994.

PHYSIOLOGICAL RESPONSES OF STRAWBERRY TO FILM WRAPPING AND

PRECOOLING METHODS.

M. D. Ferreira, J. K. Brecht*, S. A. Sargent and J. J.

Aracena

Horticultural Sciences Department

IFAS, University of Florida

Gainesville, FL 32611-0690

Additional index words. Fragaria x ananassa Duch., forced-air

cooling, hydrocooling, film wrap, decay, quality

Abstract. Tests were conducted to compare the feasibility of hy-

drocooling as an alternative to forced-air cooling for strawber

ries. 'Selva' and 'Sweet Charlie' berries were commercially

harvested at a full-ripe stage and cooled on the day of harvest

by hydrocooling (HC), forced-air cooling (FA), or room cooling

(RC). The berries were then stored with or without a vapor bar

rier (PVC film) for 7 to 12 days at 1 or 7.5C, followed by 1 day at

20C to simulate commercial handling conditions. In initial tests

comparing HC with or without chlorine to RC, there was no ev

idence of injury or increased decay in HC berries. In subse

quent tests, HC berries retained better color after storage than

FA strawberries. HC berries retained greater weight than FA

berries after storage whether or not they were wrapped with

PVC film. Wrapped berries were firmer, and had lower soluble

solids content (SSC), but total titratable acidity (TTA) and pH

were not affected. Firmness was greater in HC berries, and

SSC was higher in FA berries, but there were no differences in

pH and TTA between the cooling methods. Decay incidence

(mainly Rhizopus stolonifer and Botrytis cinerea) ranged from

0 to 5% in HC berries, and 2.5 to 7.5% in FA berries. These tests

indicate that HC has potential for more rapidly cooling straw

berries than conventional FA without significantly affecting

decay incidence.

Rapid removal of field heat from freshly harvested com

modities (ie. precooling) retards respiration, ripening, senes

cence, water loss and decay, thus helping to maintain quality

and prolong shelf life (Mitchell, 1992a). Rapid precooling is

most critical for commodities such as strawberry which have a

high rate of metabolism. The process of removing field heat

can be achieved by several different methods, such as room

Florida Agricultural Experiment Station Journal Series No. N-01078.

cooling (RC), forced-air cooling (FA), hydrocooling (HC),

contact icing and vacuum cooling, each differing in efficiency

of heat removal. Strawberries are typically cooled using FA, a

method which allows strawberry temperatures to be reduced

from circa 30C to less than 5C within about 1 hour under nor

mal commercial conditions. Delays in cooling harvested

strawberries of as little as 2 hours at ambient field tempera

ture (29C) in California have been reported to reduce the

number of marketable berries (Mitchell et al., 1964), and a

delay of 6 hours at 30C before precooling Florida strawberries

has been shown to result in increased water loss, softening,

and losses of sugars and vitamin C (Nunes et al., 1995). Thus,

it is usually recommended that strawberries should be cooled

to temperatures near 0C as soon as possible (within 1 hour)

after harvest to limit deterioration and decay (Boyette et al.,

1989; Mitchell etal., 1964; Talbot and Chau, 1991). However,

for commercial strawberry operations, this ideal is rarely

achieved due to factors such as the volume of strawberries

handled, cooling and handling equipment availability, and

capability, economics, energy, and market conditions (Talbot

and Chau, 1991).

Hydrocooling is a more rapid precooling method than FA

and is successfully used to cool such commodities as aspara

gus, snap beans, cantaloupes, celery, cherries, sweet corn,

peas, peaches, and radishes (Hardenburg et al., 1986). In a

comparison of cooling methods for snap beans, the 7/8-cool-

ing time was reduced from about 2 hours for FA to only 3.5 to

4 minutes for HC in a flume system (Sargent, Brecht and

Risse, unpublished). Hydrocooling can be accomplished by

flooding with, spraying with, or immersing in cold water, and

is an effective and rapid precooling method that minimizes

water loss (and may even add water) and removes loose debris

and chemical residue (Mitchell, 1992b). However, decay

problems and the ability of the commodity to withstand water

contact may be limiting factors when using this precooling

method.

Strawberries are not hydrocooled commercially, appar

ently due to concerns that decay problems might be exacer

bated by the free water left on the berries after HC (Boyette

et al., 1992; Kasmire and Thompson, 1992; Mitchell, 1992c;

Ryall and Pentzer, 1982). However, there is little documenta

tion in the research literature for this concern. In fact, reports

Proc. Fla. State Hort. Soc. 107: 1994. 265

of tests of HC for strawberries have consistently concluded

that HC results in better quality berries than other cooling

methods (Goble and Cooler, 1962; Roa et al., 1977; Rose and

Gorman, 1936). Proper sanitation methods and efficient

cooler management to achieve thorough cooling are critical

elements for successful use of HC. Use of chlorine in the HC

water will prevent the accumulation of bacteria and fungi that

may otherwise infect the produce (Ryall and Lipton, 1979).

The objectives of this study were to evaluate the tolerance of

strawberries to water and chlorine during HC, compare HC

to FA for strawberries, and determine the effects of inhibiting

water loss during subsequent storage using a PVC film wrap.

Materials and Methods

Preliminary HC tests. 'Selva' strawberries were obtained

from a commercial strawberry operation near Plant City dur

ing the 1991-92 season. Individual baskets of strawberries (12

per treatment) were weighed, then cooled either by placing

them onto open wire shelves in a cold room at 1 or 7.5C (RC)

or by immersion into an ice-water bath (HC). The berries in

the RC treatments were 7/8 cooled in about 6 hours. The HC

was done in a 27.5 x 28.8 x 50 cm insulated container contain

ing 15 liters of water with ice added as needed to keep the wa

ter temperature below 1C. The baskets to be hydrocooled

were placed in nylon mesh citrus bags before immersion in

the ice water to keep the berries from floating. The baskets

were held in the ice water until the berries reached a temper

ature of 2 or 8C (approximately 2 and 4 min, respectively) as

determined by measuring the pulp temperature of randomly

selected berries with a thermocouple temperature probe.

The strawberries were stored at 1 or 7.5C for 8 days. The

weights of four baskets of berries from each treatment were

measured every 2 days during the storage period to deter

mine weight loss. Firmness was measured every 2 days on 10

non-decayed berries from one basket per treatment using an

Instron Model 1132 (Instron Corp., Canton, OH) equipped

with a 5 kg load cell and 13 mm convex tip probe. The berry

firmness was measured on two opposite sides as the bioyield

point using a crosshead speed of 10 cm min"1. Decay inci

dence was determined after 8 days in the remaining four bas

kets per treatment.

Strawberry tolerance to chlorine was determined by ex

posing 'Selva' berries to 0, 50, 100 or 200 ppm NaOCl during

HC as described above. To separate possible phytotoxicity

symptoms from shrivelling due to water loss, two baskets from

each chlorine treatment were stored uncovered and two were

wrapped with 60-guage PVC film (PF-92, Polyvinyl Films,

Inc.). The berries were evaluated after 12 days at 1C.

Comparison ofHC to FA.. Three tests were conducted dur

ing the 1992-93 season with 'Sweet Charlie' strawberries ob

tained from a commercial farm in Floral City. The berries

were sorted to obtain 40 fruit (four baskets) per treatment of

full ripe stage, uniform size, and free from defects. The straw

berries were conditioned after harvest for 6 hours at 30C and

75 to 80% relative humidity prior to 7/8 cooling by either FA

or HC. Hydrocooling treatments, with and without chlorine

(1C water, 200 ppm free chlorine, pH 9), were conducted as

described above except that the water was recirculated using

a pump (Little Giant Pump Co., Oklahoma City, OK, 115

V.A.C., 1.7 amps, 1 HP). Forced-air cooling was accomplished

with a unit designed to simulate commercial FA systems for

strawberries (Nunes et al., 1995), which cooled the berries

from 30C to 4C in about 1 hour. After HC or FA, the berries

were stored for 7 days at 1C, followed by 1 day at 20C, either

uncovered or wrapped with a 75-guage PVC film (W44-75,

RJRFilmco, Inc.).

The baskets of strawberries were weighed before cooling

and after storage to determine weight loss. Firmness measure

ments were made after storage as described above except that

a 16 mm probe was used to measure the force required to

cause 3 mm deformation on one side of each berry. Incidence

and severity of decay were evaluated after the final period of

storage in all experiments. For severity, the Horsfall-Barratt

scale was used to estimate the amount of berry surface area af

fected by decay: 1=0-1%; 2=1-3%; 3=3-6%; 4=6-12%; 5=12-

25%; 7=50-75%; 8=75-88%; 9=88-94%; 10=94-97%; 11=97-

99%; 12=99-100% (Horsfall and Barratt, 1945).

Fruit surface color measurements were made at the equa

torial region of each berry after the final storage period in all

three experiments with a Minolta CR-200b chroma meter

(Minolta Corp., Ramsey, NJ). The CIELAB (L*, a*, b*) scale

was used. Color measurements were expressed in terms of val

ue (L), hue angle (tan1 b/a), and chroma (a2+b2)1/2

(McGuire, 1992). Ripening of strawberries is accompanied by

darkening or decreasing L, increasing chroma or color satu

ration, and decreasing hue as red color development occurs.

Samples for compositional analyses were obtained by

blending the 10 berries of each replicate in a Waring blender

to make a homogeneous slurry. The fruit slurry was frozen in

plastic freezer bags for later analyses. Upon thawing, the slur

ry was centrifuged for 20 minutes at 5,000 x g in a refrigerated

centrifuge. The decanted, semi-clear juice was strained

through cheesecloth and placed in a 50 ml tube, covered with

parafilm, and frozen for later analysis of soluble solids con

tent (SSC), total titrable acidity (TTA), and pH. For ascorbic

acid analysis, the fruit slurry was combined with a mixture of

6% metaphosphoric acid and 2N acetic acid. The fruit slurry

and acid mixture were combined in a ratio of lg:10 ml, then

frozen until used. Upon thawing, the fruit slurry-acid mixture

was centrifuged for 20 min. at 5,000 x g and the supernatant

filtered through Whatman #1 paper before analysis (see be

low).

The SSC was measured with a Mark II Abbe refractometer

(Cambridge Instruments, Inc., Buffalo, NY). The TTA was

measured by diluting 6 g of the strawberry juice with 50 ml of

distilled water and titrating with 0.1N NaOH to a pH 8.2 end-

point with an automatic titrimeter (Fisher Scientific, Pitts

burgh, PA). The TTA was calculated using the milliequivalent

factor for citric acid (0.064), the major acid in strawberry

juice. The pH of the juice was determined with a pH meter

(Model 140, Corning Medical and Scientific Instruments,

Medfield, MA) standardized to pH 4.0 and pH 7.0. Ascorbic

acid content was measured using the dinitrophenylhydrazine

method of Terada et al. (1978). Concentrations of total ascor

bic acid were calculated as mg 100 g tissue fresh weight"1 from

the absorbance measured at 540 nm using a standard curve.

Results

In the preliminary HC tests with 'Selva' strawberries, there

was significantly less water loss and shrivelling after HC than

FA (P=0.05), with HC berries at 1C showing actual gains in

weight that were maintained through nearly 6 days of storage,

at which time HC berries had lost only 0.1% of their initial

weight while RC berries had lost 4.2%. After 4 days at 7.5C,

266 Proc. Fla. State Hort. Soc. 107: 1994.

Table 3. Color, firmness, SSC, TTA and pH of wrapped and unwrapped 'Sweet Charlie' strawberries after 7 days at 1C plus 1 day at 20C following HC or FA\

Treatments L Value Hue angle Chroma

Firmness

(N)

SSC TTA

pH

HC No Chlorine/Unwrapped

HC No Chlorine/Wrapped

HC Ch/orine/L'n wrapped

HC Chlorine/Wrapped

FA Unwrapped

FA Wrapped

LSD at P=0.05

36.20

38.24

37.06

37.65

34.67

36.00

26.66

28.23

26.71

26.95

23.77

25.26

40.93

43.52

41.67

43.18

38.61

41.24

10.10

11.57

9.12

10.69

4.80 y

9.15

7.90

8.75

8.32

10.55

8.85

0.83

0.78

0.86

0.79

0.91

0.88

3.50

3.48

3.53

3.48

3.56

3.51

1.22 1.47 1.69 0.10 0.69 0.07 0.07

'Color and firmness data are means of 40 measurements; SSC, TTA and pH data are means of four measurements,

'measurements not taken.

Hydrocooled berries apparently can absorb water equal to

at least 2% of their fresh weight during HC. The appearance

of the HC berries immediately after removal from the HC

bath showed some watersoaking at points on the surface

where the skin was abraded or bruised, but these areas had a

normal appearance by the time they were next examined,

about 24 hours later. In contrast, FA berries lost weight con

tinuously during the storage period. Rose and Gorman

(1936) also reported that washed berries showed a gain in

weight when compared to air-cooled berries and Goble and

Cooler (1962) reported that HC berries had little weight loss

or some weight gain during handling. Plastic film wrap

helped maintain berry weight over time during both storage

periods. This agrees with the findings of Collins and Perkins-

Veazie (1993), who found that polyethylene wrap dramatical

ly reduced water loss in strawberries stored at 1C and 5C for

about two weeks. It was also reported by Roa et al. (1977) that

HC berries wrapped with a PVC film had lower weight loss

than non-HC berries.

Hydrocooled strawberries were firmer than FA berries in

these tests and wrapped berries showed greater firmness than

unwrapped berries, independent of the cooling method. The

greater water loss in FA berries made them relatively flaccid

and less resistant to applied force compared to the more tur

gid HC berries. When firmness was initially measured as the

bioyield point, differences between HC and FA berries were

unclear, but this appeared to be due to toughening of the epi

dermis as a consequence of water loss, making the FA berries

appear firmer.

Hydrocooled, wrapped berries showed the best overall

color, the original color being retained for a longer period

than with FA berries. This agrees with Roa et al. (1977), who

concluded that wrapped, HC berries showed no difference in

color from fresh berries and presented the best quality com

pared to non-HC berries. Collins and Perkins-Veazie (1993)

also reported that strawberries which were wrapped snowed

less change in red color during storage. We have found that

anthocyanin synthesis continues after harvest in stored straw

berries (Nunes, Brecht, Morais and Sargent, unpublished).

Environmental conditions that tend to retard senescence also

inhibit the accumulation of red pigments, maintaining the

strawberries nearer the at-harvest color.

Differences in SSC, TTA and pH between the cooling and

wrapping treatments appear to be due to differences in water

loss. Wrapped, FA berries, which lost about 3% of their initial

fresh weight, had SSC and TTA levels similar to unwrapped,

HC berries. There were also no differences in ascorbic acid

levels among the treatments, but this may also be related to

water loss since it has been observed that reduction in water

activity can retard degradation of ascorbic acid in plant tissue

(Lee and Labuza, 1975). These results suggest that the tem

perature of the berries during storage may be more signifi

cant in the retention of sugars, acids and other metabolites

than the relatively minor reduction in time to reach that tem

perature achieved by HC compared to FA.

Conclusion

Hydrocooled berries wrapped with PVC film showed bet

ter color quality after storage than FA berries. Wrapped ber

ries showed higher L (less darkening), higher hue angle

(more typical reddish orange color) and higher chroma

(more intense color) than unwrapped berries. Hydrocooled

berries had less weight loss (and in some cases a weight gain)

than FA berries. Incidence and severity of decay were not sig

nificantly higher for HC treatments compared to FA. Since

the time necessary to hydrocool strawberries is less than 10%

of that required for FA, adoption of HC has the potential to

significantly speed the throughput of strawberries in commer

cial cooling operations. This should minimize delays between

harvest and precooling that can negatively impact strawberry

quality. In addition, HC can be adapted to in-line grading and

packing operations. Proper system design and management

in terms of adequate refrigeration capacity and water flow,

product residence time, and sanitation (ie. chlorination) will

be critical if this cooling method is to be successfully adopted.

Literature Cited

Boyette, M. D., E. A. Estes and A. R. Rubin. 1992. Hydrocooling. Maintaining

the quality of North Carolina fresh produce. North Carolina Agric. Ext.

Serv. Circular 414-4.

Boyette, M. D., L. G. Wilson and E. A. Estes. 1989. Postharvest cooling and

handling of strawberries. North Carolina Agric. Ext. Serv. Circular 413-2.

Collins, J. K. and P. Perkins-Veazie. 1993. Postharvest changes in strawberry

fruits stored under simulated retail display conditions. J. Food Qual.

16:133-143.

Goble, W. E. and F. W. Cooler. 1962. Quality and consumer acceptance of hy

drocooled strawberries. Tennessee Agric. Exp. Station Bulletin 344.

Hardenburg, R. E., A. E. Watada and C. Y. Wang. 1986. The commercial stor

age of fruits, vegetables and florist and nursery stocks. U. S. Dept. of Agric.

Handbook 66.

Hochberg, Y. and A. C. Tamhane. 1987. Multiple comparison procedures. Wiley, N.Y.

Horsfall, J. G. and R. W. Barratt. 1945. An improved grading system for mea

suring plant diseases. Phytopathology 35:655. (Abstr.)

Kasmire, R. F. andj. F. Thompson. 1992. Cooling horticultural commodities.

III. Selecting a cooling method, p. 63-68. In: A. A. Kader (ed.). Posthar

vest technology of horticultural crops. Publ. 3311. University of Califor

nia.

Lee, S. H. and T. P. Labuza. 1975. Destruction of ascorbic acid as a function

of water activity. J. Food Sci. 40:370-373.

268 Proc. Fla. State Hort. Soc. 107: 1994.

McGuire, R. G. 1992. Reporting of objective color measurements. Hort-

Science 27:1254-1255.

Mitchell, F. G. 1992a. Cooling horticultural commodities. I. The need for

cooling, p. 53-56. In: A. A. Kader (ed.). Postharvest technology of horti

cultural crops. Publ. 3311. University of California.

Mitchell, F. G. 1992b. Cooling horticultural commodities. II. Cooling meth

ods, p. 56-63. In: A. A. Kader (ed.). Postharvest technology of horticultur

al crops. Publ. 3311. University of California.

Mitchell, F. G. 1992c. Postharvest handling systems: small fruits (table grapes,

strawberries, kiwifruit), p. 223-231. In: A. A. Kader (ed.). Postharvest tech

nology of horticultural crops. Publ. 3311. University of California.

Mitchell, F. G., E. C. Maxie and A. S. Greathead. 1964. Handling strawberries

for fresh market. Calif. Agric. Exp. Station Ext. Serv. Circular 527.

Nunes, M. C. N.,J. K. Brecht, A. M. M. B. Morais and S. A. Sargent. 1995. Phys

ical and chemical quality characteristics of strawberries after storage are

reduced by a short delay to cooling. Postharv. Biol. Technol. (in press).

Roa, R. D., J. H. di Pendima and D. R. Guemes. 1977. The technical feasibility

of export of fresh strawberries to Germany by air. Revista del Instituto de

Technologia de Alimentos 2:79-88.

Rose, D. H. and E. A. Gorman. 1936. Handling, precooling, and transporta

tion of Florida strawberries. Florida Agric. Exp. Station Technical Bulle

tin 525.

Ryall, A. L. and W. J. Lipton. 1979. Handling, transportation and storage of

fruits and vegetables. 1. Vegetables and melons. AVI, Westport, Conn.

Ryall, A. L. and W. T. Pentzer. 1982. Handling, transportation and storage of

fruits and vegetables. 2. Fruits and tree nuts. AVI, Westport, Conn.

Talbot, M. T. and K. V. Chau. 1991. Precooling strawberries. Florida Coop.

Ext. Sen'. Circular 942.

Terada, M., Y. Watanabe, M. Kunitoma and E. Hayashi. 1978. Differential

rapid analysis of ascorbic acid and ascorbic acid-2-sulfate by dinitrophe-

nylhydrazine method. Anal. Biochem. 84:604-608.

Proc. Fla. State Hort. Soc. 107: 269-271. 1994.

POSTHARVEST QUALITY OF SOUTHERN HIGHBUSH BLUEBERRIES

P. Perkins-Veazie and J. K. Collins

USDA-ARS

South Central Agricultural Research Laboratory

Lane, OK 74555

J. R. Clark

Department of Horticulture and Forestry

University of Arkansas

Fayetteville, AR 72701

J. Magee

USDA-ARS

Small Fruit Substation

Poplarville, MS 39470

Abstract. The early ripening southern highbush blueberry is a

valuable commodity, but little is known about fruit quality or

shelflife of the new cultivars and breeding selections. 'Cape

Fear', 'Cooper', 'Gulfcoast', 'O'Neal' and the breeding selec

tion MS108, were harvested in Arkansas in 1993 and 1994. 'Si

erra', which has some southern highbush parentage, and the

rabbiteye cultivars 'Climax' and Tifblue' were also included.

Fruit were held at 5C, 90% RH for 21 days then one day at 20C,

80% RH. Southern highbush fruit weights ranged from 1.5 g for

'Cooper' to 2.1 g for 'O'Neal'. 'Climax', 'Tifblue', 'O'Neal', and

'Sierra' fruit had the smallest stem scar diameters (1.3 to 1.5

mm). Following storage, soluble solids concentration changed

little. 'Sierra' fruit had very little (<10%) decay. 'Gulfcoast' and

'Cooper' fruit were considered the least acceptable of the

clones studies due to high percentages (20 to 30%) of pedicel

adherence, decay and soft fruit, and large stem scar tears. 'Si

erra' and 'O'Neal' fruit were judged to be as good as or better

in postharvest quality than the commercially important 'Cli

max' and 'Tifblue' cultivars.

The storage life of rabbiteye {Vaccinium ashei Reade) and

northern highbush {Vaccinium corymbosumh.) blueberries has

Mention of a trademark, proprietary product, or vendor does not consti

tute a guarantee or warranty of the product by the USDA and does not imply

its approval to the exclusion of other products of vendors that may also be

suitable.

been studied extensively (Ballinger et al., 1978; Makus and

Morris, 1993; Miller et al., 1988; Smittle and Miller, 1988).

The southern highbush blueberry (Vaccinium spp.) is a hybrid

derived largely from V. corymbosum and V. darrowii Camp, par

entage and has a low chilling requirement and earlier ripen

ing date than rabbiteye cultivars (Lyrene, 1990). Acreage

planted in southern highbush blueberries is predicted to ex

pand greatly by the year 2000 (Moore, 1993).

The storage life of rabbiteye blueberry fruit is reported to

be superior to that of northern highbush fruit due to less fun

gal decay (Makus and Morris, 1993). However, only a few

southern highbush blueberry cultivars have been studied for

fruit quality. Miller et al. (1993) found that southern high

bush 'Sharpblue' fruit softened more rapidly than 'Climax'

rabbiteye fruit during storage. Lang and Tao (1992) reported

that stored southern highbush fruit of 'Gulfcoast' was of low

er quality than 'Sharpblue'. Although 'Sharpblue' acreage is

currently the largest in the world, this cultivar has stem scar

tearing, and corolla and pedicel adhesion, making it a poor

quality cultivar in areas without early markets. Additionally,

other low-chill cultivars are needed to diversify blueberry

acreage.

With the predicted expansion of southern highbush blue

berry plantings, evaluation of fruit from new southern high

bush germplasm is needed. The purpose of this experiment

was to evaluate the berry quality and shelflife of 'Sierra' and

five southern highbush clones and compare these with two

commercially important rabbiteye cultivars, 'Tifblue' and

'Climax'.

Materials and Methods

Blueberry fruit were harvested from the southern high

bush cultivars 'Cape Fear', 'Cooper', Gulfcoast', 'O'Neal',

and the breeding selection MS108 in 1993 and 1994. 'Sierra',

which was released as a northern highbush cultivar, but in

cludes several southern Vaccinium spp. in its parentage, was

included. The rabbiteye cultivars 'Climax' and 'Tifblue' were

used as standards. 'Sharpblue' does not consistently fruit in

Arkansas and was not used in this experiment. Established

plants used for harvests were not sprayed with fungicides

Proc. Fla. State Hort. Soc. 107: 1994. 269