Tropical Fruits and Nuts

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CHAPTER 4 IN TEXT.

Introduction
There are many types of tropical fruits. Some are exotic and not found commonly in temperate regions of the world. Others are well known cultivars such as tomatoes, squash, green peppers and cucumbers. None of these can survive winters such as occur in Illinois. We circumvent this problem by planting them as annual crops.
Most of the other types of tropical crops are perennials that cannot be cultivated in temperate zones of the world.
There are many more types of fruits in the tropics than in temperate portions of the world, but few of them are introduced here. The situation has changed in recent years.
Many exotic tropical fruits are "in". Most are gathered wild, cultivated on a local scale and consumed locally. Bananas, citrus crops, pineapples and avocados are major exceptions.
See the table of tropical fruits and nuts on pg. 76.
Tables of production, p. 77.

Bananas
Bananas (Musasp.) are from south east Asia. The taxonomy is complex. They were early taken to Madagascar and Africa by the Indonesians. In 600 B.C. they were in India. Alexander the Great saw them there. In 1522 in West Africa. To the Americas by 1516.
Most banana species have seeds. The common cultivars are sterile triploids.
Most bananas in the tropics are probably cooked. Many are eaten fresh. Most of ours are the latter type. The rise of bananas as a cultivated crop is linked to the history of the United Fruit Company. In 1900, the company developed a good transport system to ship bananas to market. They perfected the conditions to ship the fruits without spoilage and to ripen them at exactly the proper time for market. They also dominated the politics of many Central American countries.
Bananas are reproduced vegetatively. This leads to many fungal disease problems.
See the figures on page 94.
Musa textilis(abaca) is used as a fiber crop.

Bananas
Plantains

Citrus crops
Citrus crops are evergreen. All come from Asia. The domesticated members are difficult taxonomically because of selection of mutants and hybridization in agricultural practice.
All have a hesperidium for a fruit. This is basically a berry with a leathery skin (exocarp and mesocarp together) and oil glands. The endocarp has modified fleshy hairs or juice sacs that are the part we eat.
Fruit keeps relatively well. None of this group is native to the low, wet tropical regions of the world. They seem to prefer dry climates with lots of sunshine. They cannot tolerate severe frosts well. The citron (Citrus medica) was the first introduced into Europe.
Almost all are propagated vegetatively. The orange (Citrus sinensis, Rutaceae) is the most widely cultivated of all of the Citrus crops. The wild ancestors are not known. Oranges transferred to the Persian empire. The Moors brought them to Spain. The Spanish and Portugese introduced them into the New World. Diagram of orange flowers etc. p. 79.
Most U.S. oranges from Florida, Texas and California.
Citrus aurantiumor bitter orange used for marmelade and liquors.
Citrus limonoften associated with Italian descent peoples. Lemons often used for flavoring foods etc. Citrus aurantifolia, the lime, from East Indies. The Arabs used them by 1000 A.D. They were introduced into Europe by 12th or 13th century. Used to treat scurvy by the British.
Citrus reticulata, the tangerine was brought to the U.S. and to Europe about 1800. From S.E. Asia.
Citrus paradisioccurred spontaneously in the West Indies. Considered to be a hybrid between the pummelo (C. maxima) and the sweet orange (C. sinensis) by some. Pink grapefruit (e.g., Ruby Red) are "sports" or somatic mutations. Ruby Red arose in McAllen, Texas in 1929 and is propagated vegetatively.
Fortunellaand Aeglealso eaten and from the same family.

Grapefruit

Pineapples.
Pineapples (Ananas comosus, Bromeliaceae) are native to the New World. They were widely distributed when Colombus came. Pineapples were domesticated by the Guaraní Indians of Paraguay etc. They are multiple fruits.
Most modern cultivars are parthenocarpic. They set seed without fertilization. Reproduced vegetatively normally. They were taken to many countries by the Portugese, Spanish, and Dutch. They were taken to Hawaii by the Doles. Hawaii in 1970's grew about 1/3 of world's supply.

Dates
Dates (Phoenix dactylifera) come from the palm family. They have long been an important food plant. Fruits of wild relatives have been gathered for thousands of years and presumably the cultivated ones arose from these.
Dates are nutritious and contain 75% carbohydrate and 2 percent protein.
Date palms are dioecious, i.e., they have male and female parts on different plants. By 2300 B.C., agriculturalists had learned how to pollinate them.

Figs
Figs (Ficus carica, Moraceae) are from the Near East. They also have been cultivated for thousands of years. This large genus contains only one important commercial fruit crop. The fig is frequently mentioned in the Bible and other Near Eastern literature.
Figs pollinated by small wasps. Some are parthenocarpic or self-pollinating. Smyrna figs have only female flowers. Smyrna and Capri figs often grown together to provide pollen source.
See diagram p. 96.

Breadfruit and jackfruit
The breadfruit (Artocarpus atilis, Moraceae) is native to Polynesia. It has also been cultivated for thousands of years. Tall trees with unisexual flowers. Forms a multiple fruit. The part eaten is formed by abortive flowers. See diagram p. 101.
Captain Bligh was sent to take them to the West Indies to feed slaves. He set out in the ship Bounty but encountered difficulties. Bligh persevered and went back and finally got breadfruit to the West Indies.
Jackfruit (Artocarpus heterophyllus) has a similar fruit but sweet tasting.

Avocados
Avocados (Persea americana, Lauraceae) are native to Mexico and Central America. They are exceptional in that they have lipids instead of sugars or starches. The mesocarp is rich in oil. 2000-2800 calories per kg.
They appear about 7000 B.C. in Mexico. They may have been independently domesticated in at least three different areas.
Primitive avocados
Avocados

Mangoes
Mangoes (Mangifera indica, Anacardiaceae) are native to southeast India. Some people are sensitive to the outside of the fruit.
Mangoes were taken to the New World by the Portugese and are now a major crop in many countries.
See diagram pg. 98.
Mangoes

Pomegranates
Pomegranates (Punica granatum, Punicaceae) are native to the Old World. They also have been cultivated for thousands of years. They were brought to Spain by the Moors by about 800 A.D. The Spanish introduced them into the New World. They are grown for both ornamentals and fruits.

Papayas
The papaya (Carica papaya, Caricaceae) is native to (probably) Central America but now cultivated throughout the tropics. They are in demand in the U.S. mostly for the enzyme papain isolated from the immature fruits.
See diagram p. 100.

Papaya

More exotic tropical fruits
Members of the genus Annona such as the sweet sop and the cherimoya. Compound fruits. The carambola (Averrhoa carambola, Oxalidaceae) is native to Asia. Now seen in our grocery stores. Kiwi fruit (Actinidia chinensis, Actinidiaceae) are native to Asia. Were introduced from New Zealand. Recently have become popular.
Passion fruit (Passiflora edulis, Passifloraceae) are native to the New World and are widely eaten. A component of Hawaiian Punch. See diagram p. 103.
Others include guavas (Psidium guayaba, Myrtaceae) (native to S. America) and several other members of this family.
The sapotes (most of these are in the Sapotaceae). The akee (Blighia sapida, Sapindaceae) was introduced from Africa to the West Indies with black slaves. The national dish of Jamaica. A number of toxicity problems are associated with this fruit. The litchi (Litchi chinensis) and the rambutan (Nephelium lappaceum) are members of the same family. Both are native to Asia. The "mamon tico" or mamoncillo (Melicocca bijuga) is native to Central and South America. Also Sapindaceae. The mangosteen (Garcinia mangostana, Clusiaceae) is native to S. E. Asia. Although really delicious, it is rarely seen outside of that part of the world.
The durian, Durio zebethinus, is legendary for its odor. This fruit, native to Southeast Asia, has a creamy texture and is quite sweet in taste.
Durians and rambutans
Ciruelas

Tropical nut crops
Many nuts have been utilized and some domesticated in the tropics as well as in the temperate portions of the world:

The coconut
Coconuts (Cocos nucifera, Arecaceae) widely used in the tropics today. They yield oil, fiber, drink, and food. We will discuss other uses later. The coconut is native to S.E. Asia and was early transported to many parts of the world by ocean currents and also by man. The coconut had apparently just arrived in the New World before Columbus.
Each fruit contains one seed. This is one of the largest seeds known.

Coconuts

The cashew
The most important tropical nut that is eaten as a nut. This fruit (Anacardium occidentale, Anacardiaceae) is poisonous until heated and the outside portions removed.
See the diagrams on pg. 105.
Cashews are native to northern South America. The "fruit" is also eaten as a fruit, but usually used for making juice. Now widely escaped and cultivated in arid tropical regions such as India, southern Africa, Mexico, Florida, the Mediterranean etc. India a major producer.

Macadamia nuts
The macadamia (Macadamia integrifolia, Proteaceae) is one of the few plants from Australia that is cultivated. They were taken from Australia to Hawaii where most macadamia cultivation is centered. The climate there is ideal and Hawaii is one of the few places that they can be grown well.

Brazil nuts
Brazil nuts (Bertholletia excelsa, Lecythidaceae) are native to Brazil. They are born in a peculiar fashion, see the diagram on pg. 106.
They are collected from wild trees. They are 66% fat and brazil nut oil is used as an edible oil in Brazil. A major Brazilian export.

Brazil nuts

Lecture slides (Tropical fruits)

Lecture slides (Tropical nuts)

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Revised February 2005

© David S. Seigler, Integrative Biology 363, Plants and Their Uses, Department of Plant Biology, 265 Morrill Hall, 505 S. Goodwin Ave., University of Illinois, Urbana, Illinois 61801, USA. 217-333-7577. seigler@life.uiuc.edu.