Overview of Rambutan Overview of Rambutan Phenology, Flowering, Phenology, Flowering, and Fruit Set in Hawai’iand Fruit Set in Hawai’i

A.M. KawabataM.A. Nagao

D.F. AokiK.Y. HaraL.K. Pena

Chanthaburi, Thailand

0

20

40

60

80

100

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Month

Te

mp

era

ture

(°F

)

Hilo Max

Hilo Min

Chanthaburi Max

Chanthaburi Min

Monsoon season

Hurricane season

Chanthaburi Rainfall

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5

10

15

20

25

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Month

Pre

cip

ita

tio

n (

in)

HiloChanthaburi

Monsoon season

Hurricane season

Cairns, Australia

0

20

40

60

80

100

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Month

Te

mp

era

ture

(°F

)

Hilo MaxHilo MinCairns MaxCairns Min

Cycl--one season

Hurricane season

Cairns Rainfall

0

4

8

12

16

20

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Month

Pre

cip

ita

tio

n (

in)

Hilo Cairns

Cycl--one season

Hurricane season

Comparisons

Chanthaburi Cairns Hawai’i

Flowering Seasons October to DecemberJuly to August; December to January; thru April

July to August; thru Nov.; March to May;

No. of Flowering Seasons

1 1; extended 2

Flushing SeasonsOct. to Dec.; Sept. (after harvest), May (monsoon)

Nov. to Dec.; Feb. to March (after harvest); May; Jul. to Aug.

Aug. to Sept.; May to June (after harvest); Oct.

No. of Flushing Seasons

2; maybe 3 4 to 5 3 to 4

Harvesting Seasons February to JuneDecember to January; thru March; thru August

Dec. to Jan.; thru Mar.; Aug. to Sept.; thru Oct.

No. of Harvesting Seasons

1 1; extended 2

Flowering in Hawai’i

• Response to water stress

• Symptom = Leaf curling

• Main season (July to August)

• Minor season (April to May)

• Anthesis takes 2-3 months, up to 9 months

• Anthesis of a panicle takes 3-7 weeks, up to 23 weeks

Rambutan Flowers

Female Male Induced Male

24-46 days 12-15 days21-52 days

0

20

40

60

80

1000

days

10 d

ays

21da

ys

31 d

ays

42 d

ays

52 d

ays

63 d

ays

73 d

ays

84 d

ays

94 d

ays

105

days

115

days

126

days

136

days

147

days

157

days

0

0.5

1

1.5

2

2.5

3

0 da

ys

3 da

ys

7 da

ys

10 d

ays

14 d

ays

17 d

ays

21da

ys

24 d

ays

28 d

ays

31 d

ays

35 d

ays

38 d

ays

42 d

ays

45 d

ays

49 d

ays

52 d

ays

Silengkeng n=22

R134 n=17

Naturally produced hermaphroditic male flowers

Flushing in Hawai’i• Response to rainfall, heavy irrigation,

pruning, harvest• Reduced by cool weather, heavy fruit

set and flowering even in presence of rainfall

• Non-synchronous• Takes 3-4 months to mature• Flushes must be mature at time of floral

induction• Main seasons (May-Jun.; Aug.-Sept.)

Fruiting in Hawai’i

• Seed filling 8-10 weeks after anthesis

• Aril/flesh development 10-12 weeks after anthesis

• Harvest 16-20 weeks after anthesis

• BRIX readings >18%

• Main season (December-January)

• Minor season (August to September)

• Extended drought prolongs harvest 3-6 months longer

Binjai - Main Season (90 ft elevation)

0.0

0.4

0.8

1.2

1.6

2.0

2 4 6 8 10 12 14 16 18 20

Weeks After Anthesis

Leng

th (i

n)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

Wei

ght (

oz)

Height

Diameter

Weight

Binjai - Minor Season (810 ft elevation)

0.0

0.5

1.0

1.5

2.0

2 4 6 8 10 12 14 16 18 20

Weeks After Anthesis

Leng

th (i

n)

0.0

0.4

0.8

1.2

1.6W

eigh

t (oz

)

Height

Diameter

Weight

Weeks After Anthesis

14 16 18

BRIX 14.9 18.2 19.1

Weeks After Anthesis

16 18 20

BRIX 14.4 16.2 18.4

BRIX