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Proc. Fla. State Hort. Soc. 118: 2005. 237

Proc. Fla. State Hort. Soc. 118:237-241. 2005.

EFFECT OF SOIL WATER DEPLETION ON GROWTH, YIELD,AND FRUIT QUALITY OF CARAMBOLA IN GRAVELLY LOAM SOIL

RASHIDAL-Y

AHYAI

,

1

F

REDERICK

S. D

AVIES

,

2

*B

RUCE

S

CHAFFER

1

AND

J

ONATHAN

C

RANE

1

1

University of FloridaTropical Research and Education Center

18905 S.W. 280 StreetHomestead, FL 33031

2

University of FloridaDepartment of Horticultural Sciences

P.O. Box 110690Gainesville, FL 32611

Additional index words.

Averrhoa carambola

, fruit yield, irrigation

Abstract.

Irrigation scheduling of carambola (

Averrhoa caram-

bola

L.) trees in South Florida is typically based on the calendaror soil appearance. The EnviroSCAN system continuouslymonitors soil water content with multi-sensor capacitance

probes and is used to schedule irrigation based on the onsetof stress principle. Our objective was to compare growth,yields, and fruit quality of 8-year-old Arkin carambola trees onGolden Star rootstock at four soil water depletion (SWD) levelsin Krome very gravelly loam soil. Soil water content rarely fellbelow the onset of stress level for irrigation and there wereno differences in tree growth, yields, or total soluble solids, atSWDs ranging from 0% (field capacity) to 17%. We hypothesizethat soil water remained at non-stress levels via capillary risefrom the water table and adequate rainfall. Mature carambolatrees growing in this soil type required considerably less irriga-tion than is typical (2-3 times/week) without adverse effects oncrop growth, yield or fruit quality.

Carambola (

Averrhoa carambola

L.) is an evergreen, tropi-

cal fruit tree native to S.E. Asia where it is primarily cultivated.The tree is also cultivated in regions of Australia, India, Israel,the Caribbean Islands, and the United States (mainly Hawaiiand Florida) (Crane, 1994; Mauro Pace, 2004, pers. comm.).A sweet type, Arkin, is the leading commercial carambolacultivar in Florida (Knight and Crane, 2002). In southernFlorida, carambola is grown in Krome very gravelly loam soilthat has a high pH (7.4-8.4), low fertility, and low soil waterholding capacity (Noble et al., 1996). Due to the hardness ofthe soil and to facilitate root growth, carambola trees areplanted at perpendicular intersections of trenches that areapproximately 50 to 75 cm wide and 50 cm deep (Colburnand Goldweber, 1961).

Fulfilling carambola tree water requirements is important

for economically profitable fruit production. Insufficient(Ismail and Noor, 1996b; Salakpetch et al., 1990) or excessive(Ismail and Noor, 1996a; Joyner and Schaffer, 1989) soil mois-ture can decrease tree growth and production. For example,increased water stress decreased vegetative growth (Ismail etal., 1994, 1996) and flowering (Salakpetch et al., 1990) of car-ambola in Australia. Even when tree growth was not affectedby drought, yield was significantly reduced in rainfed trees

compared to irrigated trees in Malaysia, mainly due to a decrease in fruit size of non-irrigated trees (Bookeri, 1996).

Little is known about water requirements and irrigationscheduling practices for carambola trees. In Australia, 30-75

mm of water per week was recommended for mature carambolatrees grown in the Northern Territory (Lim, 1996) and northern Queensland (Galn Saco et al., 1993). In southern FloridaCrane (1994) recommended 33 mm per ha twice a week duringdry periods throughout the year. However, water applicationrates and frequencies that meet tree water requirements for optimum growth and yield have not been established.

Understanding tree water requirements is important forproper irrigation management of carambola trees in subtropical climates such as that of South Florida. The EnviroScansystem (Sentek Sensor Technologies, Stepney, Australia) habeen developed for irrigation scheduling based on continuously monitoring soil water content with multisensor capacitance probes. The system comes with proprietary software

(EnviroSCAN 4.0, Sentek PTY Ltd., Kent Town, Australia) forplotting soil water depletion (SWD) over time and determining the full point (field capacity), the refill point (time toirrigate), and the theoretical onset of water stress, based onthe rate of soil water depletion (SWD) (Paltineanu and Star1997). Irrigation decisions using SWD measurements arebased on maintaining soil water content between the fulpoint and the refill point and irrigating before the occur-rence of the onset of water stress. However, this approach toirrigation may be more applicable to annual, herbaceouscrops than to fruit trees. Trees can tolerate longer periods oflow soil water content than herbaceous plants through specialized long- and short-term physiological, phenological, anatomical, and morphological adaptations (Ludlow, 1989)

such as growth reduction, stomatal closure, and osmotic adjustment (Hsiao and Acevedo, 1974). Also, in carambola orchards in Krome very gravelly loam soil, it may be difficult forsoil water content to fall below the refill point due to capillarywater movement from the shallow water table to the root zone(Al-Yahyai et al., 2005).

The objective of this study was to determine the effects ofour levels of SWD on growth, yield and total soluble solidcontent in fruit of mature orchard-grown carambola trees inKrome very gravelly loam soil.

Materials and Methods

Plant Material and Soil Properties.

The study was conducted

in an orchard of 8-year-old Arkin carambola trees grafted onopen-pollinated Golden Star rootstocks in Krome very gravelly loam soil, classified as a loamy-skeletal, carbonatic, hyperthermic, Lithic Udorthents (Nobel et al., 1996) inHomestead, Fla. (25.5N Lat. and 80.5W Long). The treeswere spaced at 4.5 m within and 6 m between rows and surrounded by an artificial (polypropylene ribbon shade cloth)windbreak on the northern, eastern, and western perimeterand sapodilla [

Manilkara zapota

(L.) von Royen] trees as windbreaks on the southern perimeter. Trees were planted at theintersection of two long trenches as is common practice in

*Corresponding author; e-mail: [email protected]


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this growing region (Colburn and Goldweber, 1961). Cultur-al practices were based on recommendations for commercialcarambola production in southern Florida (Crane, 1994).

Soil Water Depletion Treatments. Soil water depletion was de-termined by monitoring soil water content with multisensorcapacitance probes (EnviroSCAN, Sentek PTY Ltd., KentTown, Australia). Capacitance probes were installed 60 cmnorth of the trunk of three trees per treatment. Each probeconsisted of four capacitance sensors located at soil depths of10, 20, 30, and 50 cm. The sensors recorded soil water contentevery 30 min and the data were stored in a datalogger and lat-

er downloaded to a portable computer for analysis.Description of the installation of the capacitance probe

system in Krome soils was previously described by Al-Yahyaiet al. (2003) and Nez-Elisea et al. (2001), and technicalspecifications of the multisensor capacitance sensors weredescribed by Paltineanu and Starr (1997). Data from the 10-,20- and 30-cm depths sensors were summed and plotted usingEnviroSCAN software (EnviroSCAN 4.0, Sentek PTY Ltd.,Kent Town, Australia) because active roots were located atthese depths as determined by looking at the rate of soil waterdepletion at different soil depths measured with the Enviro-Scan system. Continuous measurements of soil water contentusing capacitance probes allowed for the determination offield capacity (FC) (Fares and Alva, 2000; Hillel, 1998; Zekriand Parsons, 1999). Field capacity values were selected basedon Veihmeyer and Hendricksons concept that define FC asthe amount of water in the soil after excess water had drainedand the rate of downward movement had decreased (Hillel,1998). After the SWD levels were reached, irrigation wasapplied for each treatment to restore soil water levels to FCusing microsprinklers with a 360 wetting pattern (Maxijet,Dundee, Fla., USA) at 89 Lh

-1

.Soil water depletion levels were predetermined based on

a preliminary study (Al-Yahyai, unpublished data) wherebyirrigation water was withheld and soil water content was mon-itored via capacitance probes until leaf yellowing and abscis-sion appeared on the trees, which were assumed to be visualindications of water stress. Irrigation was initiated when SWD

reached one of the following four levels (where 0% SWD =FC): 0-8% SWD, 9-11% SWD, 12-14% SWD, or 15-17% SWD.

Growth, Yield and Fruit Quality Measurements.

Shoot growthwas measured on four randomly selected, actively growingbranches per tree. The shoots were tagged at 10 cm below theshoot apex and measured using a ruler.

Fruit from six trees per treatment were harvested duringAugust (summer harvest) and December (winter harvest) o

Fig. 1. Soil water depletion (SWD) levels from above field capacity to visi-ble symptoms of stress in an 8-year-old Arkin carambola orchard in Kromevery gravelly loam soil. The range of percentage SWD for each of four treat-ments between field capacity and visible symptoms of water stress are indicat-ed by horizontal lines.

Table 1. Total irrigation time and amount of water applied to 8-year-oldArkin carambola trees irrigated at four different levels of soil waterdepletion (SWD) in an orchard on Krome very gravelly loam soil during2002 and 2003.

SWD (%)

2002 2003

Totalirrigationtime (h)

Total amountof water applied

(Lyr

-1

)

z

Totalirrigationtime (h)

Total amountof water applied

(Lyr

-1

)

z

0-8 21 1869 22 1958

9-11 16 1424 15 1335

12-14 12 1068 11 97915-16 10 890 7 623

Total rainfall (mm) 1,355 1,606

z

Based on an application rate of 89 Lh.

Fig. 2. Effect of soil water depletion (SWD) on shoot length of 8-year-oldArkin carambola trees during 2002 and 2003. Symbols with vertical bars represent means SE of 4 shoots per tree on 6 trees.


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2002 and 2003. The harvest dates coincided with commercial

peak harvesting months for carambola trees in southern Flor-ida. Fruit from six trees per treatment were harvested on Dec.2002 and Dec. 2003. Fruit were sorted based on the stage ofmaturity and color: immature (115 hue), mature (108 hue),and ripe (tree-ripened; 87 hue) as determined with a colo-rimeter (Minolta Chroma Meter, Minolta, Inc., Ramsey, N.J.).Fruit were then counted and weighed to determine the totalyield. Total soluble solids (TSS) of 20 randomly selected ma-ture and 20 ripe fruit per tree were determined for six treesper treatment using a refractometer.

Experimental Design and Statistical Analyses. Treatments werearranged in a completely randomized design. Each treatmentconsisted of three rows with five trees per row. Two trees wererandomly selected from each row for growth and yield mea-

surements. Data were analyzed by repeated measures, analysisof variance using SAS Version 8.2 software (SAS Institute, Cary,N.C.) and linear regression using Sigmaplot 2002 (SPSS, Inc.,Redland, Calif.). For regression analysis, the mean SWD levelof each SWD treatment was used as the independent variables.

Results and Discussion

Irrigation Measurements.

Soil water content declined in atypical stepwise pattern over the course of the experiment(Fig. 1) and never reached the onset of stress levels in the

field. The length of time between irrigations required to reacheach SWD treatment level in May 2002 is shown if Fig. 1. At

that time, it took 14 to 15 d (from 5 May to 18-19 May) for thesoil water content to go from field capacity to 15-16% SWDThis is a much longer duration between irrigations than is typical in most growers orchards in South Florida where trees aregenerally irrigated 3-6 times per week (J. H. Crane, personalcorrespondence with carambola growers). The total yearly duration of irrigation applied in our study ranged from 10 h forthe wettest (0-8% SWD) to 22 h for the driest (15-16% SWD)treatments (Table 1). This is a fraction of the 548 to 2190 h ofirrigation yearly that is often applied by carambola growers(J. H. Crane, personal communication with four commerciacarambola growers). Thus, commercial carambola growerssurveyed apply as much as 21,700 to 115,739 L per tree peryear. In contrast, we applied as little as 890 and 623 L per tree

per year to the wettest treatment in 2002 and 2003, respectively which is considerably less than 0.1% of the amount of waterapplied by the carambola growers surveyed (Table 1).

Shoot Length. Shoot elongation from March to Septemberin 2002 and from April to December in 2003 (Fig. 2) did notsignificantly differ among SWD treatments and followed atypical shoot growth pattern for carambola trees. The lack ofshoot elongation differences in response to treatments couldbe attributed to having sufficient soil water content throughout the experiment. Frequent precipitation (1,355 mm in2002 and 1,606 mm in 2003, Table 1) and capillary rise from

Fig. 3. Total number of mature (108 hue according to colorimeter read-ings) and tree-ripened (87 hue) Arkin carambola fruit in an 8-year-old or-chard irrigated at four different soil water depletion (SWD) levels during2002 and 2003.

Fig. 4. Total fresh weight of Arkin carambola fruit irrigated at four different soil water depletion (SWD) levels during 2002 and 2003.


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the water table located 1-2 m below soil surface may have pro-

vided an adequate water supply to the trees. In Malaysia, suf-ficient rainfall also resulted in no significant difference inshoot growth rate between irrigated and rain-fed, field-growncarambola trees (Bookeri, 1996). Moreover, carambola treescan tolerate periods of low soil water content once they areestablished (Galn Saco et al., 1993).

Fruit Number and Weight.

There was more variability in fruitnumber and weight among treatments in 2002 than in 2003(Figs. 3 and 4). The number and weight of mature (108 hue)and ripe (tree-ripened; 87 hue) fruit in 2002 and 2003 werenot significantly different among SWD treatments (Fig. 3).Similarly, in a study of carambola trees in Malaysia, Bookeri(1996) found that irrigation treatments did not affect fruitnumber, but irrigated trees had fruit that were 17% larger

than those of non-irrigated trees. In this study, soil water con-tent did not reach sufficiently low levels to cause water stressand resulted in no significant differences in fruit length,number or weight among treatments. This lack of differencesin fruit number or weight related to treatment further sup-port our contention that SWD never reached critical levels.

Total Soluble Solids (TSS) Content. Total soluble solids con-tents of ripe and mature fruit harvested in 2003 were higherthan those harvested in 2002 (Figs. 5 and 6). Total soluble sol-ids content was higher than that reported previously (6.8-7.2%)

for carambola in southern Florida (Campbell and

Koch, 1989; Crane et al., 1998). There was no significant effec

of SWD treatments on TSS of ripe or mature fruit. In caram-bola fruit, TSS content often varies from harvest to harvest (JC. Crane, unpublished data), but the reasons for this have notyet been elucidated. However, due to variability of TSS withinharvest dates, no conclusion can be made on the effect of SWDtreatments on ripe fruit TSS for carambola trees in this study.

Conclusions

Shoot growth and yields of carambola trees were not affected by SWD within the range tested (0-17%). Sufficient soiwater content from precipitation and capillary water movement from the shallow water table possibly resulted in sufficient soil water content to obtain adequate vegetative growth

and yields. Fruit length, number and weight did not differ significantly among SWD treatments. Similarly, TSS content didnot follow a specific trend in response to irrigation at variouslevels of SWD. Differences among SWD treatments in matureand ripe fruit fresh and dry fruit weight were highly variableThus, it appears that irrigation of carambola trees in Kromevery gravelly loam soil in an orchard can be applied at orabove 17% SWD without a significant effect on fruit yield orquality. This further suggests that carambola growers insouthern Florida could reduce irrigation levels without having adverse effects on tree growth, yield or fruit quality.

Fig. 5. Total soluble solids content of tree-ripened (87 hue based on col-orimeter readings) Arkin carambola fruit irrigated at four different soil wa-ter depletion (SWD) levels during 2002 and 2003.

Fig. 6. Total soluble solids content of mature (108 hue based on colorimeter readings) Arkin carambola fruit irrigated at four different soil water depletion (SWD) levels during 2002 and 2003.


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Literature Cited

Al-Yahyai, R., B. Schaffer, and F. S. Davies. 2003. Monitoring soil water con-tent for irrigation scheduling in a carambola orchard in a gravelly lime-stone soil. Proc. Fla. State Hort. Soc. 116:37-41.

Al-Yahyai, R., B. Schaffer, F. S. Davies, and J. H. Crane. 2005. Phenological cy-cles of carambola trees are minimally affected by four levels of soil waterdepletion. HortTechnology 15:623-630.

Begg, J. E. and N. C. Turner. 1970. Water potential gradients in field tobacco.Plant Physiol. 46:343-346.

Bookeri, M. 1996. Effect of irrigation on carambola (

Averrhoa carambola

) pro-duction in drought prone areas. pp. 317-320. Proc. Intl. Conf. Trop. Fruit.Kuala Lampur, Malaysia.

Campbell, C. A. and K. E. Koch. 1989. Sugar/acid composition and develop-ment of sweet and tart carambola fruit. J. Amer. Soc. Hort. Sci. 114:455-457.

Colburn, B. and S. Goldweber. 1961. Preparation of oolitic limestone soil foragricultural use. Proc. Fla. State Hort. Soc. 74:343-345.

Crane, J. H. 1994. The carambola (starfruit). Fact Sheet HS-12. IFAS, Univ.of Fla., Gainesville.

Crane, J. H., R. J. Knight, Jr., O. Rodriguez, and L. C. Crane. 1998. Cultivartree growth and fruit quality evaluation of young carambola (

Averrhoa car-ambola

L.) trees. Proc. Fla. State Hort. Soc. 111:299-302.Fares, A. and A. K. Alva. 2000. Evaluation of capacitance probes for optimal

irrigation of citrus through soil moisture monitoring in an entisol profile.Irr. Sci. 19:57-64.

Galn Saco, V., U. Menini, and H. Tindall. 1993. Carambola Cultivation.FAO Plant production and protection paper 108. FAO, Rome, Italy.

Hillel, D. 1998. Environmental soil physics. Academic Press, New York, N.Y.Hsiao, T. C. and E. Acevedo. 1974. Plant responses to water deficits, water use

efficiency, and drought resistance. Agr. Meteorol. 14:59-84.Ismail, M. R. and K. M. Noor. 1996a. Growth and physiological processes ofyoung starfruit (

Averrhoa carambola

L.) plants under soil flooding. Sci.Hort. 65:229-238.

Ismail, M. R. and K. M. Noor. 1996b. Growth, water relations, and physiolog-ical processes of starfruit (

Averrhoa carambola

L) plants under root growthrestriction. Sci. Hort. 66:51-58.

Ismail, M. R., S. W. Burrage, H. Tarmizi, and M. A. Aziz. 1994. Growth, planwater relations, photosynthesis rate, and accumulation of proline inyoung carambola plants in relation to water stress. Sci. Hort. 60:101-114

Ismail, M. R., M. K. Yusaf, and A. Masturi. 1996. Growth and flowering of water stressed starfruit plants and response to ameliorated water stress. ProcIntl. Conf. Trop. Fruit. Kuala Lampur, Malaysia. 2:97-106.

Joyner, M. E. and B. Schaffer. 1989. Flooding tolerance of Golden Star carambola trees. Proc. Fla. State Hort. Soc. 102:236-239.

Knight, R. J., Jr. and J. H. Crane. 2002. The Arkin carambola in FloridaProc. Fla. State Hort. Soc. 115:93-93.

Li, Y. C., J. H. Crane, B. Boman, and C. Balerdi. 2000. Irrigation managemensurvey for tropical fruit crops in South Florida. Proc. Fla. State Hort. Soc113:40-42.

Lim, T. 1996. Carambola. 2: Growing and Marketing. Agnote 663-D32Northern Territory, Australia.Ludlow, M. M. 1989. Strategies of response to water stress, pp. 269-281. In

K. Kreb, H. Richter, and M. Hinkley (eds.). Structural and functional responses to environmental stresses: Water shortage. SPB Acad. Publ., theNetherlands.

Noble, C. V., R. W. Drew, and V. Slabaugh. 1996. Soil survey of Dade County area, Florida. USDA, Natural Resources Conservation Serv., Washington, D.C

Nez-Elisea, R., B. Schaffer, M. Zekri, S. K. OHair, and J. H. Crane. 2001.In situ soil-water characteristic curves for tropical fruit orchards intrenched calcareous soil. HortTechnology 11:65-69.

Paltineanu, I. C. and J. L. Starr. 1997. Real-time soil water dynamics usingmultisensor capacitance probes: Laboratory calibration. Soil Sci. Soc. Amer. J. 61:1576-1585.

Salakpetch, S., D. W. Turner, and B. Dell. 1990. The flowering of carambola(

Averrhoa carambola

L.) is more strongly influenced by cultivar and watestress than by diurnal temperature variation and photoperiod. Sci. Hort

43:83-94.Zekri, M. and L. R. Parsons. 1999. Determination of field capacity in a Floridasandy soil and drainage time at different depths. HortTechnology 9:258261.

Zekri, M., R. Nez-Elisea, B. Schaffer, S. K. OHair, and J. H. Crane. 1999. Multisensor capacitance probes for monitoring soil water dynamics in the ooliticlimestone soil of South Florida. Proc. Fla. State Hort. Soc. 112:178-181.

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