Local names:
Fijian (doi selawa,doi damu,doi), Samoan (toi), Tongan (toi)
A. zizyphoides is a fast growing, medium-sized to large tree up to 20-30 m tall at maturity with 10-15 m crown diameter. Leaves simple, alternate, oblong-ovate to lanceolate, 5-18 cm long and 3-6.5 cm wide, shiny dark-bright green on the upper surface, and tomentose light grayish-green below. The leaves are usually rounded at the base. Flowers in short, 3-10 cm long axillary/near-terminally positioned, flat-topped clusters. Individual flowers bisexual, small, whitish/light green, fragrant, and arranged in fives. The seapals are light green with fine, silvery hairs, while the petals are white: both sepals and petals are about 2 mm long. Fruit globose to broadly ovoid drupe, about 6-9 mm in diameter, with a conspicuous ring-like calyx scar; it turns from green to purplish green and then to brown-black at maturity. When fully mature the spongy exocarp/mesocarp flesh dries and falls away, exposing two arillate seeds, each enclosed by a hard case. Seeds smooth, brown, flattened, and oval, about 4 mm long, more or less enclosed by a loose, reddish brown aril.
Ecology
Toi mainly occurs in lowland and lower montane forest associations. It is a pioneer and early secondary species regenerating following disturbance in different forest associations. It can be found in both dense and drier forest types, in scrub thickets, woodlands/savannas and on reed-covered hills.
Native range
American Samoa, Cook Islands, Fiji, French Polynesia, New Caledonia, Niue, Tonga, Vanuatu, Wallis and Fortuna Islands
Tree management
The species grows well in monocultures. In shaded situations and inside plantations the species has excellent self-pruning characteristics, and is likely to pollard reasonably well. For joint production of timber, fuelwood and medicine, a close initial spacing is recommended in order to encourage a straight bole form and self-pruning. Spacing should vary between 5-50 trees per hectare. In the traditional system of managed natural regeneration, the straightest and best formed saplings should be weeded to keep them free of climbers and occasionally high-pruned to produce clear boles. Weeding should be undertaken frequently in the first two years prior to canopy closure. From about age 3-6 years, the smaller trees should be thinned to provide fuelwood. Since border trees develop poor form, it is preferable to plant outside edges with a different species.
The mature dry fruits, with seeds showing, should be collected from the tree canopy. There are 8900 dry fruits per kg, with two seeds per fruit. The seed storage behavior is orthodox and may be successfully stored for many years in hermetically sealed containers under cool, dry conditions. Seeds should be soaked in water for 12-24 hours to improve the germination rate in older seed batches (e.g., more than 10 months old).
Toi mainly occurs in lowland and lower montane forest associations. It is a pioneer and early secondary species regenerating following disturbance in different forest associations. It can be found in both dense and drier forest types, in scrub thickets, woodlands/savannas and on reed-covered hills.
Stand establishment using natural regeneration; direct sowing; root stock and transplanting of wildings. Seeds should be sown in trays in a protected, sunny situation and be covered with a thin (2-3 mm) layer of sand, loamy soil or potting medium. Germination should commence about 7-16 days after sowing, but some seedlots take several months to germinate.
The leaves and young shoots of Alphitonia species are consumed by cattle but have been found to have low digestibility and nutritional status.
Apiculture: The species is reportedly a good source of nectar for bees.
Toi is one of the premier fuelwoods of the Pacific Islands; its habit of shedding dried, lateral branches provides a convenient source of high quality fuelwood. In some areas, such as on Santo in Vanuatu, the wood is collected, bundled and sold as fuelwood in local markets.
Timber: The timber is used in house construction and for the manufacture of tools, weapons, and handicrafts and furniture with good technical properties, easy to saw, finish, and season. The wood is also used to make canoes and canoe paddles.
Shade or shelter: The tree casts an intermediate level of shade, which would be too heavy for most crop species but ideal for somewhat shade-tolerant crops such as cardamom, cocoa, coffee, Morinda, soursop, and Xanthosoma.
Medicine: The bark, often in combination with other species, is used for treatment of stomachaches, constipation, coughs, headaches, menstrual pain, and prolapsed rectum in postpartum women. The sap is used to treat earache, swelling, fever, and cancer. A phenolic compound in the bark, alphitol, has been shown to have anti-inflammatory activity.
Ornamental: Toi is an attractive, fast-growing, and moderately long-lived tree with a good ornamental potential.
Boundary or barrier: The species is known to be used for living fences. It has good resistance to cyclones and would be well suited for inclusion as an upper-mid-level layer of mixed-species windbreaks of wide dimensions (e.g., greater than 50 m across
Soil improver: Toi has rapid growth, combined with a fairly quick turnover of leaves in the canopy, suggesting it has good potential to build organic matter, especially if grown together with legumes. It also has great potential in silvopastoral systems.
Intercropping: A. zizyphoides has excellent potential for planting or inclusion in improved fallow systems due to its rapid regeneration and biomass production. Its presumed deep rooting habit would help facilitate cycling of mineral nutrients from lower soil profiles.