Developing Off-season Production Technique for Rambutan By Roedhy Poerwanto Center for Tropical Fruits Studies Bogor Agricultural University Indonesia 8/21/2009 1
Introduction As a tropical country, Indonesia is rich in fruits of several species, one of which is rambutan (Nephelium lappaceum L.). Rambutan is one of Indonesian s native fruit trees. In Indonesia, rambutan is categorized into primary fruit and it comes around 3.5% of total fruit production. Its short selflife has been a constraint in its distribution. As a result, export of the fruit is very limited and can only be done by air. 8/21/2009 2
Rambutan Production and Harvesting Area Production (ton) 900.000 100.000 800.000 700.000 600.000 500.000 400.000 300.000 200.000 100.000 - Production (ton) 1998 1999 2000 2001 2002 2003 2004 2005 2006 Years 90.000 80.000 70.000 60.000 50.000 40.000 30.000 20.000 10.000 - Harvesting Area (Ha) 8/21/2009 3 Harvesting Area (Ha)
Rambutan Producing Areas Sumatra Java Borneo Celebes Borneo : South Borneo (Banjarmasin) Celebes : N. Celebes, C. Celebes, S. Celebes Sumatra: Aceh, N. Sumatra, W. Sumatra, Riau, Jambi, Lampung Java : DKI Jakarta, W. Java, C. Java, E. Java 8/21/2009 4
Indonesian Variety of Rambutan Varieties Rapiah Lebak Bulus Binjai Garuda Characteristics of fruit Very sweet with good aroma, hair is coarse with yellow colour, fruit is small, low productivity, Combine of sweet & sour, juice, hair is dense with red colour, fruit size medium, high productivity Sweet & dry with a bit of sour, skin bright to dark red the hair is not so dense, fruit size medium and relatively productive Sweet, fruit size is very big, red hair with yellow tip, high productivity Productivity (kg/tree) 18-30 50-100 40-70 200-270 8/21/2009 5
Rambutan Variety Lebak Bulus Binjai Rapiah Garuda 8/21/2009 6
OFF-SEASON PRODUCTION Either at tropical or temperate region the fruit production is seasonal. At peak season oversupply of fruits always happen and at off-season there is no supply at all. This condition is not economically interesting because it cause sharp fluctuation of fruit price. Prolonging the fruiting season, which earlier the beginning of the season and delaying the end of season could benefit farmers and consumers. The orchard can be managed to flower at difference time, or it is not all trees produce flower and fruit at the same time. This can be achieved by improvement of off-season fruit production technology. 8/21/2009 7
Satsuma Off-season Production in Japan Growing cycle of satsuma mandarin in Japan Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Natural condition Very early cv Early cv. Late cv. Off-season cropping Early forcing Late forcing Very early cv. : Miyamoto, Ueno, Yamakawa Early cv. : Miyagawa, Okitsu Late cv. : Aoshima, Hayashi, Sugiyama, Otsu No.4, 8/21/2009 8
FLOWERING REGULATION OF TROPICAL FRUITS One of the critical points on fruit production is the induction and development of flowers. From several experiments on tropical fruit trees, it was found that flowering induction need suppression of vegetative growth. The suppression of vegetative growth occurred because the trees were exposed to drought stress. Drought stress in the dry season is the main factor for flower induction. In almost all tropical fruit trees, the induction of flowering occurs during the dry season and the flowers emerge at the beginning of the rainy season, with fruit harvested 3-6 months later. 8/21/2009 9
Drought Stress Main factors for flower induction of tropical fruit trees: Mangoes: 3 dry months Citrus: 1-2 dry months Rambutan: Binjani & Garuda: 2 weeks of draught stress Rapiah, Lebak Bulus: 1 month of drought stress The buds will differentiate to form flowers after the trees experience the water stress. To produce numerous and good flowers, trees need a favorable environment for growth and development of flowers after induction of the flowers in dry season. 8/21/2009 10
FLOWERING REGULATION OF TROPICAL FRUITS It is difficult to obtain soil conditions dry enough to induce flowering during the rainy season. There are several ways that can be used for flower forcing of fruit trees, including: manipulation of air and soil temperature, water stress, girdling, and application of plant growth regulators. 8/21/2009 11
FLOWERING REGULATION OF TROPICAL FRUITS Induction of flowering on citrus and other fruit trees depends on decreasing in gibberellins activity. Flower formation of several tropical fruit trees can be inhibited with applications of gibberellins. Gibberellins activity on citrus leaves of inducted branches were lower than non-inducted branches. Application of gibberellins has been shown to inhibit flowering Therefore, application of anti-gibberellins can be expected to force the tree into flowering. Paclobutrazol, a substance that inhibits gibberellins biosynthesis, induced flowering in several tropical fruit trees. 8/21/2009 12
PACLOBUTRAZOL Poerwanto et al. (2008) developed: the technology to manipulate mangoes, mangosteen, citrus, durian to flower and produce fruit off-season using a combination of paclobutrazol and KNO 3 application. However, this technology was not effective for rambutan 8/21/2009 13
Ringing On Year Healthy Rambutan Trees subjected to be treated Ringing by discarding bark in the trunk on: April 22, May 6, May 20, June 3, June 17 One month after ringing, the wound has recovered, the tress sprayed with 30 g/l KNO3 on: 1 month after ringing 2 month after ringing 3 month after ringing 8/21/2009 14
Effects of Ringing and KNO3 Spraying on Rambutan Flowering & Fruit Production Treatments Flowering Time (DAT) Flowering Date Inflorescences per tree Flowers per Inflorescence Production (kg) Check 176.23 9 OCK 183.67 404.47 7.97 Time of Ringing No Ringing 107.56 a 8 AUG 202.00 441.49 10.22 ab 22-Apr 52.00 b 13-Jun 207.28 477.73 5.84 b 6 May 50.67 b 26-Jun 228.33 424.36 11.97 a 20 May 54.33 b 13-Jul 197.22 475.31 8.32 ab 3 June 50.78 b 24-Jul 233.00 507.84 5.28 b 17 June 40.22 c 28-Jul 215.44 481.32 8.23 ab Time of KNO 3 Spraying (month after ringing): No KNO 3 204.00 414.4 7.97 a 1 month 51.28 214.50 452.29 8.11 a 2 months 64.67 203.44 480.93 7.17 a 3 months 71.33 223.69 470.81 9.77 a 8/21/2009 15
Ringing Off Year Treatment: Control Ringing Ringing followed by spraying KNO3 Month of Ringing April 2000 May 2000 June 2000 8/21/2009 16
Effects of Ringing and KNO3 Spraying on Flowering of Rambutan in Off-Year Treatments Flowering Date Flowering Time (DAT) Inflorescence per tree Production (kg) Ringing on April: Control 25/9 (2 trees)* 151 2 0 Ringing 18/7-23/8 99 112 5.74 Ringing + KNO3 11 23 /7 77 229 11.45 Ringing May: Control 28/9(2 trees)* 124 4 0 Ringing 9/8 4 /9 84 133 7.12 Ringing + KNO3 3 23 /8 71 84 4.34 Ringing June: Control 20 /9(1 trees)* 86 4 0 Ringing 6/8 14/9 78 72 3.86 Ringing + KNO3 16/8 14 /9 71 163 8.15 8/21/2009 17
Rining in On-year & Off-year No Ringing in on-year No Ringing in off-year Ringing in off-year Ringing in on-year: No Ringing in off-year Ringing in off-year The trees were sprayed with KNO 3 one month after ringing treatment Observation on Off-Year: - number and length of shoot, number of inflorescences, number of flowers, fruit set and fruit production - starch content (leaves, bark of branch, small root) - nitrogen content (leaves) 8/21/2009 18
Effect of Ringing in Flowering and Fruiting of Rambutan at Off-Year Treatment Days to Flowering No. of Inflorescences No of Fruits Bunch No. of Fruit/ Bunch Number of Fruits/tree No Ringing in On-Year No Ringing in Off-Year Ringing in Off- Year Ringing in On-Year 109 b 203 84 4.3 b 364 a 86 a 377 190 9.2 b 1713 c No Ringing in Off-Year Ringing in Off- Year 113 b 318 116 7.2 b 906 bc 92 a 153 101 8.9 b 896 b 8/21/2009 19
Figure 1. Starch fluctuation in the leaf of Rambutan Binjai 50 45 40 35 % Starch 30 25 20 15 10 5 0 No Ringing in 2000 and 1999 No Ringing in 2000 and Ringing in 1999 Ringing in 2000 and No Ringing in 1999 Ringing in 2000 and 1999-1 WAR 1 WAR 2 WAR 3 WAR 4 WAR 8 WAR 12 WAR 35 WAR Time of Sampling 8/21/2009 20
Figure 2. Nitrogen fluctuation in the leaf of Rambutan Binjai 3.5 3 % Nitrogen 2.5 2 1.5 No Ringing in 2000 and 1999 No Ringing in 2000 and Ringing in 1999 Ringing in 2000 and No Ringing in 1999 Ringing in 2000 and 1999 1-1 WAR 1 WAR 2 WAR 3 WAR 4 WAR 8 WAR 12 WAR 35 WAR Time of Sampling 8/21/2009 21
Figure 3. C/N Ratio in the leaf of Rambutan Binjai 25 20 C/N Ratio 15 10 5 0 No Ringing in 2000 and 1999 No Ringing in 2000 and Ringing in 1999 Ringing in 2000 and No Ringing in 1999 Ringing in 2000 and 1999-1 WAR 1 WAR 2 WAR 3 WAR 4 WAR 8 WAR 12 WAR 35 WAR Time of Sampling 8/21/2009 22
How ringing induce flowering? Inhibition of photosynthate translocation from shoot to the roots: increasing of C/N ratio in the shoots. roots lack of energy to do their activities: the capacity and the ability of roots decreases significantly in: absorbing water, absorbing mineral nutrition, synthesizing of growth hormone. Low rate of mineral nutrition absorption, especially nitrogen increase C/N ratio in the shoots Less water absorption will results in physiological water stress in the plants. Decrease synthesis of hormone including gibberellins. 8/21/2009 23
THE ROLE OF KNO 3 Accelerate the emergence of Rambutan flowers: Flowers sprouted 2 months earliear (August vs October) dormancy breaking substances, to break the dormant bud, especially generative buds in deciduous trees K +: increasing translocation of sucrose from leaves to buds, in the increase of sucrose synthesis, increase in sucrose transportation rate in apoplast of leaves mesophyl, increase sucrose content in phloem, direct impact of the increase of osmose pressure 8/21/2009 24
PRECAUTIONS USING THIS TECHNIQUE Must be mature trees; at least they have produce fruits for 2-3 times. The bark discard from the trunk must be less than 2 cm, as the wound completely recover after up to 2 years. The wider the bark discard, the late the wound recover. The wound must be covered with black plastic tape soon after ringing to assure the callus grows without any obstructions. The trees must be sprayed with 30-40 g/l KNO 3 at one month after ringing, to force the flower buds to spout. Foliar spray with KNO 3 in concentration more than 40 g/l cause the leaves drop. Several trees decease after producing off-season fruits at the second year ringed. Thus the treatment may be done only one time in two years (after the wound completely recover). 8/21/2009 25
Thank You 8/21/2009 26
HOW RINGING INDUCED OFF-SEASON FLOWERING IN RAMBUTAN? Ringing affected the starch reserve in the top and roots of the trees. It inhibits translocation of photosynthate from shoot to the roots so that carbohydrate accumulates in the shoots. In the trees that got ringing, the starch content in the leaves and the bark of the twigs was higher while that in the roots was lower. Trees that got ringing have higher starch content in their leaves and twigs than those getting no ringing. The increase of starch content in the leaves caused the C/N ratio to be higher when the trees were induced to flower. C/N ratio of the leaves went up 44-70% higher in a week after ringing and 24% higher when the trees were induced to flower. A high ratio of C/N in shoots is important in flowering. 8/21/2009 27
HOW RINGING INDUCED OFF-SEASON FLOWERING IN RAMBUTAN? It seems that in Rambutan trees, accumulation of carbohydrate in the shoots is needed for flower induction. The flower induction in Binjai rambutan was affected by the increase of carbohydrate content in the top. The regression value between number of inflorescences and the starch content in the leaves was 98.4% (very significant) and between numbers of inflorescences with the starch content in the twig bark was 97.8%. As there was more starch content in the top, the trees flower faster. 8/21/2009 28
HOW RINGING INDUCED OFF-SEASON FLOWERING IN RAMBUTAN? When the first flowers appear, the starch content in the leaves and the bark decreased. The content in the twig bark was 5-9% lower compared with that in Week 3 while that in the leaves decreased as much as 21% compared with that in Week 8. This happened because the starch was hydrolyzed and sent to meristem for flower induction. This indicated that there was a conversion of starch into soluble sugar and it moved to meristem where flowers are induced. 8/21/2009 29
HOW RINGING INDUCED OFF-SEASON FLOWERING IN RAMBUTAN? Inhibition in translocation of carbohydrate to the roots will make them lack of energy to do their activity. The flowering time was not only affected by the starch accumulation in the top and C/N ratio, but also by decreasing starch content in the roots. The starch content in the roots of the trees that got ringing treatment was lower than those that did not, and the trees flowered earlier. The regression result indicated that the starch content in the root with the flowering time had the value of 99.6% (very significant). 8/21/2009 30
HOW RINGING INDUCED OFF-SEASON FLOWERING IN RAMBUTAN? As a result, the function of roots in absorbing water, mineral nutrition, and synthesizing of growth hormone decreases. Low absorption of mineral nutrition, especially nitrogen due to ringing will also increase C/N ratio in the shoots of the trees. 8/21/2009 31
HOW RINGING INDUCED OFF-SEASON FLOWERING IN RAMBUTAN? Less water absorption will results in physiological water stress in the plants. From the previous research it is identified that water stress will induce flowers of several fruit trees. Water stress will hydrolyze starch and protein to be a simpler form to be used by plants to induce flowers. 8/21/2009 32
HOW RINGING INDUCED OFF-SEASON FLOWERING IN RAMBUTAN? A decrease in the starch accumulation in the root due to ringing was predicted to cause a decrease in the ability of roots synthesize hormone including gibberellins. Imbalance of the hormone in the root affected gibberellins distribution to top part of the tree. The flower induction in rambutan supposes need a decrease of gibberellins in the top of the tree. The result of our previous research indicates that GA3 content of rambutan leaves was at a minimum level during the dormant phase before flowering 8/21/2009 33
THE ROLE OF KNO 3 Application of KNO 3 accelerate the emergence of Rambutan flowers. The trees that were not given any treatment at all produced flowers in early October, while tress that were not treated with ringing but sprayed with KNO 3 flowered in early August. Spraying of KNO 3 one month after ringing led the trees produced flowers earliest. Hence, without being sprayed with KNO 3, the plants given ringing can produced flowers, but when they are sprayed one month after ringing, flowers will emergence 20 days earlier. The spraying of KNO 3 does not have any effects on the number of inflorescences, number of flowers per inflorescence and the size of inflorescence. 8/21/2009 34
THE ROLE OF KNO 3 KNO 3, a dormancy breaking substances, is applied to break the dormant Rambutan bud. Potassium Nitrate turns to have the ability of breaking dormant buds, especially generative buds in deciduous trees KNO 3 is able to break dormant bud of mango trees. The results of previous experiment with mangoes also indicate that KNO 3 can break the dormant flower buds that as a results of paclobutrazol treatment. 8/21/2009 35
THE ROLE OF KNO 3 The ability of KNO 3 in breaking dormancy might be related to the role of ion K + in: increasing translocation of sucrose from leaves to buds, in the increase of sucrose synthesis, increase in sucrose transportation rate in apoplast of leaves mesophyl, increase sucrose content in phloem, direct impact of the increase of osmose pressure 8/21/2009 36
Paclobutrazol, apply to the roots by soil drenching, or to leaves or buds, able to induce off-season flowering of mango and mangosteen. The ability of paclobutrazol to induce off-season flowering is based on its effect on inhibiting gibberellins biosynthesis. Paclobutrazol 8/21/2009 37
Application Method of Paclobutrazol Paclobutrazol usually apply through soil drenching However on mango foliar spray is also effective as well. Application by foliar spray could be the choice of technique since it has no residual effect, while soil drenching application will have residual effect for more than 2 years 8/21/2009 38
Mango As other fruits, In Indonesia, flower induction of mango is occurred on dry season. However, not like other fruit trees, the mango need 2-3 months drought to flower, and flower will develop even though the rainy season is not started yet. Induction of off-season flowering of mango is relatively easy. Soil-drench application of paclobutrazol followed by foliar spray of KNO3 is effective for flower forcing of mango. 8/21/2009 39
Mangosteen Mangosteen flower is induced by drought stress at dry season, and the flowers develop and differentiate soon after the beginning of rainy season. Mangosteen tree can be induced for earlier flowering by using drought stress or application of paclobutrazol that inhibit gibberellins biosynthesis. 8/21/2009 40
Durian Naturally durian trees are only induced to flower by dry season and the flower develops at the beginning of rainy season. The second period of flowering is happen at the middle of rainy season if at the first period flower has not developed into fruit. Application of paclobutrazol for flower induction is less successful for durian. Paclobutrazol is only effective if applied during dry season while in nature the induction is also happen at dry season. to be effective to force durian to flower, the application of paclobutrazol need to be accompanied by several weeks of drought. While without paclobutrazol, drought season is already a good stress to induce flowering on durian. 8/21/2009 41
FLOWERING REGULATION OF TROPICAL FRUITS There are several ways that can be used for flower forcing of fruit trees, including: manipulation of air and soil temperature, water stress, girdling, and application of plant growth regulators. Paclobutrazol, applied to the roots by soil drenching, or to leaves or buds, was able to induce off-season flowering of mangoes and mangosteen. The ability of paclobutrazol to induce off-season flowering was based on its effect on inhibiting gibberellins biosynthesis. 8/21/2009 42
Rambutan Earlier experimental results: the application of paclobutrazol + by dormancy breaking substance mango, mangosteen, durian, and citrus trees flower in off-season. However, the same treatment given to rambutan trees has not indicated any satisfactory results. Therefore, another treatment to induce rambutan flowers in off-season has been conducted by applying ringing technique 8/21/2009 43