Achachairu, bacuri, achacha.

Garcinia (Rheedia) gardneriana

Origin:

This tropical plant is originally from Bolivia, and has since been spread to Brazil and many other lowland tropical countries.

Climate:

Colder winter weather can cause a large drop of flowers and fruit. It fares best with ample rainfall of 1500-2500mm/pa, and in its native environment can tolerate flooding for extended periods.

Plant Description:

It is an evergreen tree with a pyramidal canopy that can grow to 5-10m in its preferred environment. It exudes a yellow latex when bruised or cut. Young leaves are pinkish-red before turning yellowish green on maturity. Achachairu is an understory tree and strong sunlight can damage young foliage.

Relatives:

Clusiaceae Family with more than 250 species in Garcinia. Taxonomy of the family has been difficult, but Rheedia has now been included in Garcinia (ie it's a synonym of the accepted name). The difficulty extends to species level and native area locals have assigned both G brasiliensis and G gardneriana to achachairu; fruit available in Australia are most likely gardneriana. The genus includes the highly valued mangosteen, and madrono, gamboge and imbe.

Soils:

Like most fruit trees it grows and fruits best in rich soils, but can survive in others with variable fertility. Neutral pH is preferred.

Propagation:

Seed is the usual means but they are recalcitrant, so drying is damaging and they are best sown fresh. Germination success decreases with duration of any seed storage. Seedlings need to be protected from full sunlight with shade cloth. With a variable number of seeds per fruit and polyembryony, some seedlings can be clones of the parent with others that may be sexual. Very low success has been found with cuttings and air layers. Grafting is difficult with the latex seemingly hindering effective contact of the cambial layers. Using achachairu as its own rootstock does not produce good results.

Cultivars:

There is variation in this species given seed propagation, but no effective systematic selection studies have been reported. Rather, the time-honoured opportunistic selection of seed from good fruiting trees has so far been the main technique of gradual improvement.

Flowering and Pollination:

Achachairu is a dioecious species sometimes stated to be andromonoecious. However non-male flowers are structurally hermaphrodite with functionally sterile stamens. Fragrant inflorescences occur as axillary cymes. Male plants have about five times as many flowers per cyme as females, and both have sucrose-containing nectaries as a reward for pollinators. There is a whorl of 10-20 free stamens and staminodes in staminate and pistillate flowers respectively, and in the latter there is a superior globular tri-carpellate ovary surmounted by a central disc-like stigma. Anthesis occurs throughout the morning, with pollination by insects including honeybees.

Cultivation:

Little known, but most likely is similar to growing mangosteen.

Wind Tolerance:

Not known.

Pruning:

Pruning is minimal to facilitate harvesting.

The Fruit:

The fruit is a berry with a smooth and hard thick skin. It changes from a bluish-green colour when immature to a yellowish-orange and then to orange-reddish colour as it ripens. The skin is thick and bitter, but easily peeled with the fingernails. The flavour is described as something between a feijoa and citrus, sweet and refreshing.

Fruit have an ovoid shape about 4-5cm long with an average weight of 35g. Normally fruit are carried inside the canopy. There can be 1-4 seeds, one sexual and others formed as a result of nucellar embryony, but many of these abort. Together, these seeds comprise a substantial fraction of the fruit. The size of the whole fruit is related to the number of non-aborted seeds.

Fruit Production and Harvesting:

Well-managed mature trees can produce thousands of fruit per year.

Fruit Uses:

They have a sweet, sub-acid flavour when fresh and are normally eaten in this way. Carbohydrate content of the fresh pulp is about 15%.

Pests and Diseases:

Fruit fly can be a problem.

Comments:

There is now a large orchard near Townsville in North Queensland marketing these fruits, and although new to most Australians, their desirable qualities are gradually being recognised.

More Achachairu info: Achachairu In Australia

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