Tamarillo (Tree Tomato)

By Ken Love

 

Family: Solanaceae

Scientific name: Cyphomandra betacea (Cav.) Sendt.

Origin: Peruvian Andes and Bolivia

 

              

 

Introduction

The tree tomato or tamarillo is a shallow rooted tree that can reach a height of 20 feet.

The wood is brittle and the trees short lived, usually lasting from 12 to 15 years. The almost heart shaped leaves can reach a foot or more in length and a width of up to 5 inches.  The fragrant flowers, up to a 1/2-inch diameter can be pink, light blue or white and are usually borne near the tips of the branches.  Trees produce fruit that is red, yellow, orange or purple, the long stemmed fruit, 3 inches long by 1.5 inches wide is generally ovoid with somewhat pointed ends. The seeds are thin, flat and hard. The tree is related to poha, tomatillo and lulo. Commonly referred to as tree tomato, the name tamarillo was devised in 1967 in New Zealand for marketing purposes.

 

Poha (Physalis peruviana)  was observed growing in Hawaii by naturalist Andrew Bloxum in 1825. Sharing a geographic point of origin with tree tomato, there is some speculation that it might have been introduced to Hawaii around the same time, both fruit having been referred to as “lost crops of the Incas”, who, cultivated the trees prior to Columbus finding the New World.

 

Varieties

The Tree tomato does not grow true from seed and there is a wide variety of fruit color and size of tree tomatoes found in Hawaii. In New Zealand, ‘Red Beau’, (1991), and ‘Kaitaia Yellow’, (1981), are two popular cultivars. Selections found in California and Florida includes ‘Rothamer’, ‘Oratia Red’, ‘Inca Gold’ and ‘Ecuadorian Orange’. Breeding programs in Brazil have also produced local selections.

 

Environment

The tree tomato is a subtropical that is usually found from the 1000 to 10,000-foot elevations in its native environment.  In Hawaii it is found from 200 to 4000-foot elevation. Trees at lower elevations tend to produce more but smaller fruit. The plants prefer a lightly compacted soil with good drainage. Roots will not tolerate standing water, which may kill the tree in a matter of days. Protection from wind is essential for these shallow rooted trees. Brittle branches are also susceptible to winds, especially when laden with fruit. Trees will produce fruit after 18 months but it is considered advisable to remove the first year’s fruit in order to strengthen the root system. Trees in New Zealand’s large commercial plantings are short lived, lasting only 4 to 6 years. In Hawaii, trees will produce up to 15 years with proper care and nutrition.  On average, a cluster of 20 flowers will produce only 4 or 5 fruit. Flowers will abort if not pollinated. It takes approximately 25 weeks from fruit set to maturity.

 

Culture

New Zealand’s commercial harvest of tamarillo averaged 1500 metric tons in 2004 with 100 tons being exported and 100 being processed. The remainder was sold as fresh fruit.

Seedlings are field planted when they are 2 to 5 inches in height, spaced from 6 to 10 feet apart. In windy areas, they are often planted closer together.  The flowers are often removed the first year and root growth encouraged. Bone meal is commonly used when planting in New Zealand.  Trees are cut back severely each year to a height of 3 to 4 feet to encourage branching. In Hawaii, a quarterly application of 1/4 pound of organic 6-6-6 is recommended.  In the 5th year of growth additional applications 2 to 3 pounds of mixed phosphate, nitrate of soda and sulphate of potash is recommended.  Annual pruning should be practiced, removing branches that   have previously fruited.  Judicious pruning can also help to extend the fruiting season and facilitate harvesting.  Irrigation is only needed in periods of drought. Good mulching will alleviate tree stress under drought conditions. Trees prefer organically rich light soil.

   

Pests and Diseases

The tree tomato is susceptible to a number of problems, which can be controlled with proper care. Fruit flies will sting the fruit. The tough skin offers protection but makes the fruit unattractive for marketing as fresh. The Hawaii Areawide Fruit Fly Pest Management Program (HAW-FLYPM) is very effective in preventing damaged fruit. The most common problem, powdery mildew (Oidium sp.), can be addressed with applications of commercial insecticide soaps and neem oil sprays. Root-knot nematodes (Meloidogyne sp.), Root rot; crown rot  (Phytophthora sp.) and wilt from Pseudomonas solanacearum also affect the plant. Good cultural practices should help to stave off these problems.

 

Propagation

Tree tomatoes can be propagated by cuttings of 1 to 2 year old growth and by seeds.

Tissue culture is practiced in New Zealand. Seeds tend to produce taller trees; better suited to protected areas while trees from cuttings tend to be shorter and bushier making them better for windy areas.

 

Harvesting and Yield

Fruit should be picked with the stem on or cut with a small piece of stem left intact. The tough skin lets pickers place the fruit into bags or directly into boxes. The fruit ripens over a 6 to 8 week period in Hawaii, generally from September through May depending on location and elevation.

 

Cultivated fields in New Zealand can produce more than 6 tons of fruit per acre. In Hawaii, a single tree can produce more than 60 pounds of fruit annually.

 

Postharvest Quality

Tree tomatoes can be stored for up to 9 weeks if kept between   37.4 to 40 °F with 90 to 95% relative humidity. The fruit suffers from chilling injury if kept below 37.4 °F. Decay occurs if the fruit is stored above 40 °F.  Peeled fruit can be processed and frozen. It can  also be placed  into jars with sugar syrup to preserve it for future use when following the USDA guidelines for preserving.

 

Cost of Production

The project tamarillo tree produced an annual marketable yield of 54.0 pounds. The average market price was $5.00 per pound, and therefore the tree generated a gross revenue of $270.00 for the year. Growing costs (fertilization, irrigation, pruning and all weed and pest control) amounted to $30.57, and harvesting costs (picking, packing and delivery to market) totaled $57.70. (All labor to grow and harvest the tamarillos 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 $88.27. The gross margin (gross revenue minus all operating costs) was $181.73.

 

The tamarillo gross margin is the amount of money available to pay all the ownership costs associated with the tamarillo 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 tamarillo enterprise can be determined by subtracting the tamarillo enterprise’s share of the total ownership costs from the gross margin for tamarillos.

 

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

The fruit is packed in egg type cartons after being graded to size in New Zealand.

Small, medium and large fruits are sold direct to wholesalers, stores and processors.

In Hawaii, imported fruit is sold individually, retailed for as much as $10.99 per pound.

Locally grown fruit sold in the Kona district to groceries is packed 3 or 4 fruit per plastic container and wholesales for $5.00 per pound. Big Island hotel and restaurant chefs purchase 10 to 20 pounds of fruit at a time packed in boxes.

 

Food Uses and Nutrition

Average Brix  (Calif. 8-10%)

Food Value Per 100 g of Edible Portion

 

Moisture                      82.7-87.8

Protein                         1.5 g

Carbohydrates             10.3 g

Fat (ether extract)        0.06-1.28 g

Fiber                            1.4-4.2 g

Ash                              0.61-0.84 g

Calcium                       3.9-11.3 mg

Phosphorus (with seeds)         52.5-65.5 mg

(without seeds)            13.1 mg

Iron                             0.66-0.94 mg

Carotene                      0.371-0.653 mg

(or calculated as Vitamin A)    540 I.U.

Thiamine                     0.038-0.137 mg

Riboflavin                    0.035-0.048 mg

Niacin (with seeds)      1.10-1.38 mg

(without seeds)            1.011 mg

Ascorbic Acid              23.3-33.9 mg

 

Tree tomatoes are highly versatile for culinary use. They can be used as a substitute for tomatoes, cut fresh in salads, served sweetened in desserts or added to spicy sauces. Chutney made with the fruit is highly valued in New Zealand and often found served in place of tomato ketchup.  West Hawaii chefs have developed a number of recipes, curries and chutneys using the fruit.

 

Recipes

Tree Tomato Rice

By Teri Wisdom

Hawaii Community College – West Hawaii Culinary Arts Program

Serving Size: 6 to 8            

                                   

Quantity                                 Ingredients

                                   

2 cups                                      sweet rice, washed and drained

2 cups                                      white rice, washed and drained

8 cups                                      water

3 tbl.                                        veggie oil

3                                              cloves of garlic, crushed

2 lbs.                                       chicken, cut into bite size pieces

1 medium                                onion, diced

3                                              chopped tree tomatoes

1 Cup                                      chicken broth

2 medium                                green bell peppers, sliced into thin strips

1 tbl.                                        annatto seeds soaked in ¼ cup water    for 30 min.

tbl.                                           raisins

1 tsp.                                       salt

1/2tsp.                                     pepper

3                                              hard cooked eggs

                                   

Procedure:

1) Cook Rice

2) Heat oil in large pot, sauté garlic till light brown.  Add chicken and brown.

3) Add onions and tree tomatoes , cook until onions are soft.

4) Add the chicken broth, cover, and simmer for 8-10 min. or when the chicken is tender.

5) Remove seeds from water and stir in veggies for the orange color.  Be sure to not add seeds.

6) Add the cooked rice, raisins, salt and pepper and mix well.

7) Cook 10 minutes more, stirring occasionally to prevent burning.

 

Tree Tomato Sauce

 

By Chef Paul Heerlein

 

6 oz ginger

4 cups white wine

36 oz passion orange juice

1 orange Zest

3 l, pineapple juice

2 tsp brown cloves

1 tbs allspice

22 lbs tree tomato

 

Procedure:

1.     In sauce pan, add white wine and ginger and reduce by half.

2.     Add all remaining items except tree tomato and reduce half way

3.     Add tree tomato and reduce to desired consistency

 

The 12 Trees Project

Is funded by the Western Sustainable Agriculture Research and Education (WSARE) USDA-CSREES competitive grants program.  54 Hawaii Island chefs, fruit buyers and growers were invited to select the types of fruit they would like to see commercially available, based on their desire to utilize the fruit in culinary applications. In selecting the final 12 fruits, considerations were given to seasonality and harvest times so that the availability of harvested fruit and on-farm labor needs were spread out over the year.

Fruit trees were planted and brought into production at a demonstration orchard at the Kona Pacific Farmers Cooperative on Napoopoo Road in the South Kona District. During the course of the three-year project, fruit from this orchard, as well as additional fruit purchased from area farmers, were donated to the West Hawaii Community College culinary school. Culinary student chefs developed recipes to be published on the project web site < http://www.hawaiifruit.net/12trees.html> and in a book in the final year of the project. Members of the cooperative as well as members of the Hawaii Tropical Fruit Growers - West Hawaii association and any other interested growers were encouraged to plant these trees. The goals of this project were to increase profitable agricultural diversification and to develop a consistently high quality, year-around supply of tropical fruit for local markets.

 

References and Further Reading

 

Verhoeven G. 1992. Cyphomandra betacea  (Cav.)Sendtner. In Coronel, R.E. & Verheij, E.W.M. (Eds.): Plant Resources of South-East Asia. No. 2: Edible fruits and nuts. Prosea Foundation, Bogor, Indonesia. pp. 144-146.

 

Morton, Julia F., 1987. Fruits of Warm Climates

 

Popenoe W. 1920. Manual of Tropical and Subtropical Fruits. The Macmillan Company pp. 452-453

 

 

Internet References:

http://www.naturalhub.com/grow_fruit_type_tamarillo_relative_new_zealand.htm

 

http://www.tamarillo.com

 

Hawaii Areawide Fruit Fly Pest Management Program (HAW-FLYPM)

http://www.fruitfly.hawaii.edu/

 

Western SARE

Sustainable Agriculture Research and Education

http://wsare.usu.edu/

 

pests & pathogens

http://www.phytid.org/CPC/Data/P.%20cryptogea.htm

 

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.