TROPICAL APRICOT

Family: Salicaceae
Synonyms: Dovyalis hebecarpa  x  D. abyssinica.
Other names: Groselha hybrida, Florida apricot.
Origin: Florida, USA.

Introduction

Tropical apricot is a natural occurring hybrid from Florida, developed in 1953 from a kitembilla, (Dovyalis hebecarpa) and Abyssinian gooseberry (Dovyalis abyssinica).

The plant has many of the attributes of both parents. It is also known as Dovyah’s Hybrid or just Dovyalis. The name ketcot was proposed in 1960 but was not widely adopted, as the fruit never achieved the popularity that was expected.  The name tropical apricot, which has been used to describe the fruit’s color and taste, is how the plant is commonly referred to in pan-tropical areas where it grows. The dovyalis should not be confused with Mamey, (Mammea americana L.), another fruit called South American apricot or tropical apricot.  

Tropical apricot is a large shrub growing in excess of 25 feet with a width that matches the height. Its tall branches are covered with 2 to 4 inch deep green leaves and often with thorns.  The branches bend downward increasing the width of the plant and are covered with numerous male, female and perfect flowers. The fruit is   thin-skinned fruit 3/4 to almost 2 inches in diameter, turn from green to pale yellow-orange to red when fully ripe. Yellow-orange   fruit are harvestable and will continue to ripen to red. The soft yellow-orange flesh is usually sour with a distinctive apricot like flavor. Some larger fruit contain 1 to 5 seeds while the majorities are seedless.

Tropical apricot is a recent introduction to Hawaii, although it’s parent, the kitembilla, (Dovyalis hebecarpa), was brought to the islands in the early 1920’s and used as a boundary plant to keep cattle out of sugar cane growing areas. Use of the kitembilla was very popular in jam and jelly, often mixed with papaya or mango.

Varieties 

Plants are usually identified as sour and less sour, thorns or nearly thornless. Thorns can be as long as 4 to5 inches on mature trees. Seedling shrubs are highly variable in thorniness  or degrees of sourness of the fruit and rate of growth. A cultivar ‘Prodigal’ is available in Florida and maybe available in a few local nurseries.

Environment

The tropical apricot, adapted to a wide range of soils from 300 to 2500 feet elevation, and has been known to survive frost in northern Florida. In deep soils with proper nutrition, the plants can grow more than 3 feet in height and width per year. Seedlings tested in South Kona showed significantly more growth in deeper soil (32 inches of soil) than those planted in rocky areas (13 inches of soil).  Mature trees will produce some fruit year around with peak production being the spring rainy season and a second moderately heavy crop in fall. Spacing of 15 feet is recommended for producing trees and 3 to 5 feet for hedgerows.

Culture  

Plants should be given a complete fertilizer, such as organic 6-6-6, quarterly. Additional minor elements should be applied yearly or twice yearly if the soil is alkaline. Heavy mulching during the dry season will help maintain the shrubs health and appearance.

Tropical apricot requires heavy pruning especially if maintained as a barrier hedge.

Removing branches with excessive thorns, dieback or lateral growth, is done to facilitate harvesting.  Thirty minutes of pruning per month was sufficient for a 20-year old tree in South Kona. Mature plants do not require as much rainfall or irrigation once established. Ten minutes of daily irrigation using a 1/4-gallon per hour emitter will increase production during off-season. The plant will fruit in full sun or partial shade. The majority of fruit form on outer branches.

Pests and Diseases

No diseases have been observed on producing trees in the South Kona district or reported in the literatures. The tropical apricot fruit is susceptible to fruit fly infestation. Following the Hawaii Areawide Fruit Fly Pest Management Program (HAW-FLYPM) is highly advisable as are following good sanitation practices, such as removing fallen and infected fruit. Birds occasionally enjoy the ripe fruit but are not a major problem.

Propagation

Shrubs are easily propagated from cuttings or from air layers, which will fruit in the first or second year after planting. Seedlings are often found under mature trees.  Seedlings generally produce fruit in 3 to 4 years but tend to have more thorns than those from cuttings or air layers. Grafting the tropical apricot to a kitembilla rootstock has been practiced in South Florida’s commercial nurseries.

Harvesting and Yield  

The tropical apricot is a heavy producer. A 15-foot tall shrub can produce more than 100 pounds of fruit per year. When harvesting for fresh sales, it is advisable to place fruit directly in a vented container in which it will be sold. Care should be taken to make sure the stem end of the fruit is intact and fruit is free of fruit fly infestation, which usually appears as a soft spot. When harvesting for processing, fruit should be processed as soon as possible after harvest as it attracts fruit flies and continues to decay.

Postharvest Quality

Once tropical apricot is harvested, it should be kept chilled to prevent decay. Tests at a South Kona grocery showed the fruit held its appearance for 20 days on store shelves before signs of mold or desiccation were visible.

Cost of Production

The project tropical apricot tree produced an annual marketable yield of 85.0 pounds. The average market price was $2.53 per pound, and therefore the tree generated a gross revenue of $214.63 for the year. Growing costs (fertilization, irrigation, pruning and all weed and pest control) amounted to $22.51, and harvesting costs (picking, packing and delivery to market) totaled $64.64. (All labor to grow and harvest the apricots was assumed to be paid at an hourly wage rate of $16.00, including withholding, FICA and benefits.) Thus, the total annual operating costs, sometimes referred to as “variable costs,” were $87.15. The gross margin (gross revenue minus all operating costs) was $127.47.

The tropical apricot gross margin is the amount of money available to pay all the ownership costs associated with the apricot enterprise. Ownership costs, sometimes referred to as “fixed costs,” include the value of land used (rent or rent equivalent or mortgage and property taxes), the value of the capital investment (such as the tree establishment cost and buildings and vehicles), the value of the management, and the value of any unpaid labor. (All paid labor is already included in the gross margin.) Ownership costs, unlike operating costs, will vary substantially from farm to farm and will depend largely on how the farming operation is financed and on economies of scale. Each grower will have to calculate his total farm ownership costs and then allocate an appropriate portion of these costs to each enterprise on the farm. Now the profitability of the apricot enterprise can be determined by subtracting the apricot enterprise’s share of the total ownership costs from the gross margin for apricots.

The cost and return data are what was obtained from the 12 Trees Project site and other locations.  Yields and costs were based on optimal growing conditions for one or more trees at various locations; different results will be obtained under different growing conditions.  The prices used were actually obtained in 2005 and 2006. There is no guarantee that these prices will continue, especially if production increases significantly.  These costs and returns are simply a starting point for growers to make their own estimates.

Packaging, Pricing and Marketing

Tropical apricot can be packaged in 1/2 pint or pint vented plastic containers for sales as fresh fruit in grocery stores and farm stands. As most produce buyers are not familiar with the fruit, smaller containers are advisable until the fruit gains a following at the market. Although the fruit has a thin skin, it holds well on store shelves. Signs in stores promoting the fruit should reflect it’s unique apricot sour taste. Fresh fruit sold to hotel chefs and restaurants can be packaged in larger containers, up to 5 pounds, but fruit should not be packed in more than 4 or 5 layers in order to protect the skin. Frozen puree can be packaged in 8-cup or smaller, freezer bags.

Fresh fruit sold to Big Island chefs for $3.50 a pound and wholesaled to groceries at $2.50 a pound. Frozen puree was sold for $40.00 per 8-cups.

Food Uses and Nutrition

Average Brix 8 to 12 (5 samples from each of 2 tropical apricot plants)
Food Value Per 100 g of Edible Portion of Kitembilla*
Moisture          81.9-86.36 g
Protein             0.174-1.5 g
Fat                   0.13-1.02 g
Carbohydrate   11.42g
Crude Fiber     1.3-1.9 g
Ash                  0.56-0.63 g
Calcium           8-13.3 mg
Phosphorus     12-26.8 mg
Iron                 0.45-1.41 mg
Carotene          0.125-0.356 mg
Thiamine         0.012-0.017 mg
Riboflavin        0.033-0.051 mg
Niacin              0.261-0.316 mg
Ascorbic Acid  64.5-117 mg

*There are no reported nutritive studies on the tropical apricot. The figures above are from a composite of studies on the kitembilla parent of tropical apricot.

The fruit is a favorite of Big Island chefs and student chefs working with the 12 Trees Project. It is easily frozen for future use either as a whole fruit or as processed puree.  Chefs have created jelly, juice, salad dressing, dipping sauces, hot sauce, BBQ sauce, pickles, chutney, soup, wine and brandy with the highly versatile fruit.  The fruit is said to have great potential for the development of value added products. As fresh fruit, those who prefer a unique sour taste enjoy it.

Acknowledgements
The author is grateful to Drs. R. Bowen, B. Brunner, K Fleming, R. Paull and F. Zee for their valuable contributions to this manuscript.