Carambolas

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Carambolas
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Worldwide Production and Distribution

• World production difficult to estimate
• Produced throughout low tropics
• Major countries include
• Malaysia
• Philippines
• Taiwan
• Thailand
• Guyana

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Worldwide Production and Distribution

• Major countries(states) also include
• Australia
• Florida
• Hawaii
• Florida production - 650 acres, high prices, but
  declining recently

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Origin and Botany

• Origin unclear - Malaysia, Indonesia, main areas
• Also distributed to Florida 1880s
• Will tolerate 0C, but not lt-4C for mature trees

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Origin and Botany

• Family - Oxalidaceae (oxalic acid)
• Includes 7 genera and 1000 species, with
  ornamentals like Oxalis
• Either sweet or acid types

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Growth and Development

• Temperature has a major effect
• Opt. 21-32C, gt35C causes fruit drop
• lt15C inhibits growth causes chlorosis, poor
  fruiting in winter

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Growth and Development

• Low soil temp also reduces yields
• Needs high rainfall and light for optimum
  production

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Growth and Development

• Seed - germinates in 7 days at opt. temps.
• Produces one embryo
• Vegetative growth vigorous
• Flowers in 4-6 yrs from seed, but lt1 yr. if
  grafted.
• Size 10 m or more when mature

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Flowering

• Flowering occurs in panicles from leaf axils
• Structure - perfect, 5 sepals, 5 pink petals, 10
  stamens

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Flowering

• Heterostyly different length, 4-5 styles fused
  into 1 fused ovary with 5 carpels.
• Heterostyly affects pollination efficiency

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Flowering

• Timing - varies with location
• Continuous flowing and fruiting in low tropics
• Florida - twice/year, April-May, Sept.- October
• Induced by stress, (water or low temperature)

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Pollination and Fruit Set

• Major limiting factor in yields - long x short
  (style) better than short x short or long x long
• Flowers- 2 weeks from formation to opening
• Flowers open, receptive 8-10 am, close 2-6 pm

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Pollination and Fruit Set

• Insect, possibly wind pollination, likely insect
  because nectar and petal color, possibly bees
• Fruit set is low, 0 (short x short) - 20 (short
  x long)

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Fruit Characteristics

• Single fleshy berry, 4-6 fused carpels, 10-12
  ovules (seeds). (Each point represents a carpel)
• Size 5-12 cm x 3-6 cm, 100-200 g
• Fruit dev. 60-70 days, sigmoid growth curve

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Fruit Characteristics

• Oxalic acid high initially, decreases with time
• Sugars increase, final 5-13
• Climacteric or non-climacteric?
• Composition (see Table 6.4, pg. 147, handout ) -
  low in everything except K, some vitamin C

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• Yields, good conditions 40-80 t/ha, variable.
  Pollination is important, 100-200 g/fruit size
• Highest in low tropics, fruit all year
• Tree yields range 100-250 kg/tree annually

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Cultivars

• Cultivars (many worldwide, propagated by
  grafting)
• Arkin (sweet)-most important
• Golden Star
• Yellow-Golden (sweet crisp)

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Rootstocks

• Rootstocks - all seedling, so vary in
  characteristics
• Again, Arkin, Golden Star used

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Cultural Practices

• Propagation
• Seeds - grown as seedlings, long juvenility
• Most commercial grafted or budded on rootstocks
  to shorten juvenility period

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• Planting and spacing
• Soils - wide range, again need well drained
  sands, loams, clays
• pH 5.5-6.5, even higher in Florida
• Site is plowed to increase drainage

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• Planting and spacing
• Planting - standard trees from nursery into
  holes, watered in
• Can be planted any time, Usually in spring in
  Florida

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• Planting and spacing
• Spacing - varies with location
• 4x4 m to 10x10 m, or 900-1000 trees/ha
• Florida common spacing is (4.6-6.2) x (6.1-7.6
  m), 292-358 trees/ha

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• Nutrition and fertilization
• Based on observation, need NPK 111
• Young trees, 0.4-0.8 kg/tree annually of
  fertilizer based on 151515 analysis

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• Pruning (important)
• Training important when young
• 3-5 shoots at 50-80 cm above soil
• Remove shoots, oldest wood

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• Pruning (important)
• Pruning
• Topping (depends on area)- lt2 m in Taiwan to
  2.7-4.0 m in Florida to help harvest, control
  tree size
• Severe pruning- often used to reshape or
  rejuvenate the tree, flowers and fruit develop on
  new shoots
• Fruit thinning - to improve size 3-4 weeks after
  flowering

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• Special practices
• Wind breaks - sensitive to wind, large structures
  are built to reduce stress
• Fruit bagged in some areas - avoids damage

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Diseases and Pests

• Diseases - several fungi
• Cercospora on leaves, fruit rots, esp.
  anthracnose
• Pests - fruit flies, moths, mites

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Harvesting and Postharvest

• Harvesting by hand
• Maturity by color, TSS
• Usually at color break, soften on tree when
  yellow

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Harvesting and Postharvest

• Postharvest
• Graded to remove poor fruit, cooled
• Storage at 5-10EC
• May use irradiation or cold to control fruit
  flies for export

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Uses

• Mainly fresh as garnish
• (star shape)
• Processing, juice, jams, candy