p 6-10. Vegetative flushing typically occurs 3-4 times yearly with pronounced flushing in May and smaller flushes in August and November. but the absence of sufficient male flowers results in poor pollination and development of deformed fruits that lack an aril. The number of male flowers peaked about 9 days after the first treatment and ceased about 7 days after the second treatment, or 15 days after the first spray. of deformed fruits that lack an aril. Although Binjai, R162, and R156 Red were very responsive to K+NAA, low numbers of male flowers were produced if panicles were not treated during the peak Abstract: Update of tropical fruit crop research. of the germination tests confirm that induced and non-induced male flowers are able to produce viable pollen for pollination.ImpactsRambutan cultivars responsive to the potassium salt of naphthaleneacetic acid (K+NAA) were identified. 10-12 weeks after anthesis. At the start of the rainy period, when rambutan becomes in season, a few festivals dedicated to the fruit are held at Surat Thani province. Hawaii has 2 harvest seasons. It is grown all over Thailand, but the best conditions for this fruit are observed in eastern Rayong province and Surat Thani in the south. The Silengkeng variety naturally produces a higher proportion Proceedings of the 13th Annual International Tropical Fruit Conference. development are responsive to NAA.ImpactsExperiments determined that the potassium salt of NAA (K+NAA), which is highly soluble in water, could be as effective as the acid form for stimulating male flower development in rambutan. It is grown commercially within 12–15° of the equator. The potassium salt of NAA is the active compound in plant growth regulators such as K-Salt Fruit Fix which is registered and used to control preharvest drop of apples and pears and for thinning of apples, olives, citrus and pears. Viability of pollen grains from NAA induced male flowers was determined with a pollen germination medium containing , 50 ppm H3BO3, 150 ppm Ca(NO3)2 4H2O, 100 ppm MgSO4 7H2O, 50 ppm KNO3 and 5% Sucrose. Yellowish or greenish skin, covered in hair-like spikes, and firm sweet juicy flesh will not leave you indifferent. Less commonly, it’s grown in greenhouses … Maximum numbers of male flowers were produced 6 to 8 days after treatment and induction ceased after about 12 days. It is grown all over Thailand, but the best conditions for this fruit are observed in eastern Rayong province and Surat Thani in the south. Flowers that were entirely closed and those with a fully exposed stigma were not responsive. Tropical Fruit Conference. It grows on hilly terrain where there is good drainage. If seeds are planted, some seedlings develop into male trees that possess only true male flowers. Andrés Ocampo of HLB Specialties, located in Florida, says: “We are currently sourcing our rambutan from Guatemala. It is high in iron, vitamin C, copper and antioxidants and while it may be rarely found in your neck of the woods, it is highly prized in Malaysia, Thailand, Burma, and Sri Lanka and into India as well as eastward through Vietnam, the Phillippines and Indonesia. True male and the functionally male flowers are the pollen sources during pollination and for good fruit set. Maximum numbers of male flowers were produced at 6 to 8 days, and production ceased after about 12 days. Fruits exhibit a simple sigmoid growth curve with the rapid growth period occurring between 10 and 16 weeks after anthesis. This project was initiated on October 1, 2002.Impacts(N/A)Publications, National Institute of Food and Agriculture, 1099 - Tropical/subtropical fruit, general/other. IR4 registration for NAA use on rambutan is being pursued.Publications, Progress 10/01/04 to 09/30/05OutputsA multi-year phenology study on rambutan (Nephelium lappaceum) trees in Hawaii is nearing completion and has shown that flowering occurs on mature terminals approximately 1-2 months after a period of water stress. The effects of multiple applications of K+NAA to individual panicles were also studied on Binjai and Jitlee. Multiple applications of K+NAA to individual panicles were also studied on Binjai and Jitlee. maximum production of male flowers occurs about 7 days after treatment, multiple applications on different panicles within an orchard will be necessary to insure that male flowers are present throughout the flowering season and to insure good pollination and fruit set.Publications, Progress 10/01/01 to 09/30/02OutputsNo progress to report.