RAMBUTAN REVISITED

(One of a series of articles about growing fruit trees in Samoa, written by Digby Gotts and published in the 'Samoa Observer' between December 2000 and April 2001)

The rambutan season is sadly drawing to a close but if you missed out on tasting these delicious morsels don’t fret too much. A second, smaller, crop is on its way and should be ready around June. This season has been the first one for growers who have cared for their trees for around 5 years. Prices at Fugalei market of $4 – 6 a kilo have made their wait worthwhile.

The MAFFM Fruit Tree Project team have had an exciting time over the past month or so sending some trial shipments of these fruits to New Zealand for market testing and to see how difficult it is to gain the approval of the NZ Quarantine service for importing this fruit. The good news is that NZ consumers enjoyed the fruit at least as much as Samoans do here, but they are willing to pay much higher prices, making the fruit a good prospect for export. The bad news is that there is still a lot of pest control work to be done in ensuring that the fruits sent to NZ are completely clean of insect pests.

MAFFM researchers have been working flat out over the harvest season testing many of the varieties of rambutan to prove to NZ Quarantine (and others) that the local fruit flies are not attracted to these fruits. This has involved breeding thousands of the flies in sealed cages and then exposing hundreds of the fruits to the flies when they are ready to lay eggs. The exposed fruit, which may have eggs inside, are then taken to another cage where they are left to allow any eggs to develop. When the larvae hatch from their egg, they leave the fruit and drop into a sawdust layer where they can be collected. Not one fruit has so far produced one larva although the trials are continuing, as there are around 8 varieties of rambutan, each of which has to be tested.

The problem pest is proving to be mealy bugs infesting the fruit. They do little damage, but there are some that are common here and not in NZ. The NZ government therefore insists that every mealy bug be removed from the fruit before they are shipped. They are easily recognised by the white hairy patches on the fruit, but not so easily removed. They are controlled on the tree by sprays of oil or soapy water, but this doesn’t remove them well enough for a quarantine standard. We have to find a safe-for-man-and-fruit cleaning process that will kill every possible mealy bug on every fruit. Work is continuing.

Another issue to be dealt with is that having identified rambutan as a strong possibility for an export crop, there are simply not yet enough trees in the country to allow an industry to become established beyond supplying the local market. Rambutan grow to be big trees and need a lot of land if they are to be grown commercially. Twenty trees, needing 2000 square meters, would be a minimum number to allow a reasonable return to a household using it’s own labour. An operation employing labour would need around 200 trees for a worthwhile return on the investment.