SAPODILLA IN AUSTRALIA

SCIENTIFIC NAME: Achras sapote, Manilkara zapota
FAMILY: Sapotaceae

The sapodilla, Manilkara zapota (syn. Achras sapota and Manilkara achras) is also known as Chico, Chiku and Naseberry. It is native to the Central Americas from Mexico to Venezuela. The sapodilla is now also widely planted in most tropical Asian countries.

Since 1975, there have been several cultivars imported into Australia, but culture here is in its early stages so local data is limited. Most information at present is interpretation of overseas literature.

Botany
The tree has an upright habit of growth of 25 m high and forms a compact head. The tree is evergreen and comparatively slow growing.

The small white flowers are borne in the leaf axils near the end of the branchlets. Flowering takes place over an extended period and fruit mature some 7-9 months later. The main flowering in North Queensland is November to February, with peak fruit set in January- February. However, there can be intermittent flowering throughout the year except for the May to July period.

The fruit is commonly round to oval in shape, 80 - 130mm long and up to 70mm in diameter. It has a thin, russet brown skin and yellowish-brown translucent flesh. Fruit weights range from 100 - 350 grams. The ripe fruit is soft and melting and some are slightly gritty in texture. All are aromatic and very sweet with low acidity. There are up to twelve shiny black seeds in each fruit.

Climatic Requirements
The zone of production of sapodillas extends to 30° north and south of the equator but most successfully within 27° of the equator. The mature tree can tolerate moderate frosts, but generally grows best at medium to low elevations in tropical areas. It is grown to an elevation of 1000 m within 12° of the equator.

The tree is tolerant to a wide range of climate from wet equatorial to dry (1000 - 3000 mm rain). Although it is successfully grown in the drier areas of India and the Philippines on 1000 mm (40") of rainfall, it favours a climate with only a short dry season.

It has tolerance to strong winds and can be grown close to the sea. However where shelter is provided, it will grow and fruit much better. Whereas established trees are tolerant of strong winds, vigorous juvenile trees may need staking for the first 3 to 4 years.

Soil
The sapodilla prefers well-drained, light to medium textured soils of acid to neutral pH, but it can be grown on a wide range of soil types.

Propagation
Seedlings take 8 - 12 years to come into bearing, but many may never fruit at all due to pollen sterility. Cultivars propagated by grafting or by cuttings will fruit in 2 - 4 years.

Propagation methods include cuttings, marcotting, approach graft, tip graft and side veneer graft. Seeds (for rootstocks) remain viable for several months but should preferably be planted as soon as possible after being extracted from the fruit.

Grafting can be done year round if the stocks are growing actively, but July to December is the preferred time. Hardened, non-flushing, terminal scions usually give the best results, and the side veneer graft is preferred.

As well as grafting on to sapodilla seedlings, related species are also being trialled for rootstocks in India and Sri Lanka. Species include Manilkara hexandra, M. kauki, Madhuca longifolia, M. latifolia. No information exists to make recommendations for Australian conditions and our own native Mimusops brownii is yet to be evaluated. The latter will, however, accept a sapodilla graft.

Orchard Layout and Planting
Suggested planting distances are rows 9 m apart and a spacing of 6 - 7 m along the rows. As the trees mature, they may need to be thinned out or else left to grow as a hedge row.

When planting, apply 100 - 150 grams of Q5 or Gran 4 in the planting hole and cover with 75 - 100 mm soil. Water the trees in thoroughly at planting.

Stake and tie young trees if they are in exposed conditions. Mulch well around trees, keeping the mulch 100 - 150 mm away from the trunk to avoid the possibility of stem rots. Airlayered plants may require extra attention in respect to staking in the early years.

Water young trees twice per week till the plants are actively growing and have obviously grown roots out into the surrounding soil. Waterings can then be made at 1 - 2 week intervals, depending on soil type and prevailing weather conditions.

Irrigation
Young trees require regular irrigation. Mature trees will benefit from irrigation during the dry season.

Fertilizing
Sapodillas are not considered to require heavy fertilizing, but should be well-grown in the early years to bring them to good bearing size at an early age.

A suggested fertilizer schedule is:

Each March, August and December100 grams of a 10:2:17 mixed fertilizer per tree per year of age.
February100 gms of urea or Nitram per tree per year of age.
August500 gms of dolomite per tree per year of age. Fertilizer rates increase to year 10 when the trees are then considered mature and fertilizer rates remain constant.

Weed control is best done by mulching around young trees and mowing as needed. Paraquat may also be used for weed control, but avoid spraying tee trunks of young trees.

Pests and Diseases
At this early stage, sapodillas in Queensland seem to be substantially free of diseases. Banana spotting bug will attack the fruit, causing split lesions with sunken areas. Spraying with Endosulphan (Thiodan, Endosan, Endopest) or Trichlorphon (Dipterex) may be needed. Some caterpillars as yet unidentified bore in to the fruit, particularly after spotting bug damage.

Harvest
The main harvest period in northern Australia seems to be September to November, with odd fruit maturing over a prolonged period, either side of the main fruiting period.

Maturity is difficult to determine. The fruit can be tested on the tree by rubbing the surface with the thumb to remove the brown felt. The skin of mature fruit is a yellowish-brown colour, while immature fruit have a green skin. Usually it is best to wait until a few fruit fall, and then initially harvest the largest fruit on the tree.

After picking, the stalk is removed and the fruit washed in water to remove the exudating sticky latex. Hard mature fruit will soften in 7 - 10 days.

Methods of packing have yet to be decided, but the sapodilla would lend itself to being packed in a cell pack in a tray similar to peaches or kiwi fruit.

Market Acceptability and Potential
The fruit is well-known in most tropical Asian countries where it is popular. Marketing to Asian countries, however, would appear doubtful because of our higher costs of production and also the long local period of production.

The potential Australian consumer is not familiar with this fruit and would have to be educated to the fruit in a promotion campaign. However, the sapodilla does not appeal to all tastes, and some people find the very sweet, treacly, caramel taste objectionable - particularly in some varieties. Varieties with gritty texture are usually rejected.

Transport and Marketing
Mature sapodillas complete the ripening cycle over a period of 7 - 10 days. This should allow adequate time for transport to market and still give a good shelf life. There should not be any problems with transport and marketing.

Varieties
Varieties preferred vary with the country of production:
In Singapore - H.C.Tan, BKD.-110 and Tropical.
In Indonesia - Betawi, Manila, Kulon, Appel Bener and Appel Linin.
In Philippines - Pineras, Ponderosa and Sawo Manila.
In Florida - Prolific, Tikal, Brown Sugar, Martin and Mead.
In India - Kalipatti, Cricket Ball, Dwarapudi and Oval.

Ponderosa is a large-fruited variety with individual fruits weighing up to 350 g. Fruit of most other varieties weigh 120 g to 200 g.

Varieties already in Australia are B.K.D, 110, Brown Sugar, C54, CGG, C58, Foster, H.C. Tan, Kai Hahn, Krasney, Makok, Martin, Mead, Oval, Pineras, Prolific, Tikal, Tropical, Sawo Manila, Lamao, See Gaa and Kulbaba.

As there is no local fruit production on which to base a choice of varieties to plant, plantings should be established of those varieties which are available. Varieties not acceptable to the market could be cut back and topworked at a later stage.

It is not expected that variety screening will be substantially completed until 1986.

Chicle
Chicle used in the manufacture of chewing gum is obtained from the latex of the sapodilla tree. The sap is harvested by tapping the tree every 2 - 3 years. Mexico, Guatemala and Belize are the main producing areas. Over recent years, the need for chicle has been largely replaced by the use of synthetic compounds.

B. Watson and J. Wait,
K.H.R.S., January 1983

DATE: March 1983

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