Cover Image


View/Hide Left Panel

Page 296

Image: jpg
~ enlarge ~

The National Academies of Sciences, Engineering, and Medicine
500 Fifth St. N.W. | Washington, D.C. 20001

Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement

Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 296
Page 296 ~ enlarge ~

OCR for page 296
Page 297 Pepino The pepino dulce 1 (Solanum muricatum) is a common fruit in the markets of Colombia, Ecuador, Peru, Bolivia, and Chile. It comes in a variety of shapes, sizes, colors, and qualities. Many are exotically colored in bright yellow set off with jagged purple streaks. Most are about as big as goose eggs; some are bigger. Inside, they are somewhat like honeydew melons: watery and pleasantly flavored, but normally not overly sweet. 2 Despite the fact that South Americans enjoy this fruit, there seems to be a curious lack of awareness for its commercial possibilities elsewhere. Although pepinos are related to, and grown like, tomatoes, they nevertheless remain a little-known crop, and their various forms are currently unexplored and underexploited. This plant's obscurity may not last much longer. In Chile, New Zealand, and California, the pepino (pronounced peh-pee-noh) is beginning to be produced under the most modern and scientifically controlled conditions. As a result, international markets are opening up. For example, the fruit has recently been successfully introduced to up-scale markets in Europe, Japan, and the United States. In Japan, consumers have an insatiable appetite for pepinos, and in recent years they have bought them at prices among the highest paid for any fruit in the world. Pepinos are offered as desserts, as gifts, and as showpieces. Often they are individually wrapped, boxed, and tied with ribbons. Some trendy stores display pepinos whether they sell or not. Its success in Japan is perhaps an indication of its future: the pepino is attractive, it has a good shelf life, it is tasty, and its shape and compact size are ideal for marketing. 1 In Spanish, “pepino dulce” means “sweet cucumber.” Regrettably, the shortened name “pepino” is becoming the common name for this fruit in English, for in Spanish “pepino” refers only to the cucumber. This fruit, however, is botanically related to tomatoes and is nothing like a cucumber. 2 Cieza de León, the Spanish chronicler of the Incas, related that “in truth, a man needs to eat many before he loses his taste for them.”

OCR for page 296
Page 298 PROSPECTS The Andes. Pepino is an ideal home garden plant; it grows readily from cuttings and is cheap to produce, and increased demand could greatly benefit home producers. Given attention by horticulturists, a colorful array of pepino types—both traditional and newly bred—could bring increased appeal to consumers from Colombia to Argentina. The transition to more extensive production has already begun. In the coastal valleys of Peru, there are some large fields of pepinos (usually rotated with potatoes, corn, and other crops). Lima is provided with the fruits year-round, and a small export trade has begun. In Ecuador, too, a few fields are grown under advanced agricultural conditions. In Chile, more than 400 hectares of pepinos are planted in the Longotoma Valley, and increasing quantities are being exported, notably to Europe. Formation of cooperatives to develop markets, coordinate transport, and control quality could lead to greater local and export earnings. There are parts of the Andes that are unaware of this crop. In Colombia, for instance, it is hardly known in most of the highland departments, although in San Agustín (Valle) and Manizales (Caldas), there are large farms (fincas) that specialize in pepinos. Other Developing Areas. In addition to its wide cultivation in outh America, the plant has been introduced to Central America, Morocco, Spain, Israel, and the highlands of Kenya. Relatively unknown in other nations but worth trying in all warm-temperate areas, this seems to be a crop with a big future fast approaching. Commercial pepino production has been suggested for southern Brazil, Uruguay, Paraguay, the highlands of Haiti, Puerto Rico, Guatemala, and Mexico—as well as for the cooler areas of Africa and Asia (particularly China). Industrialized Regions. This crop has potential for production in many parts of Europe, North Africa, the eastern Mediterranean, North America, Australasia, South Africa, and Japan, although in some areas it may have to be grown under glass or plastic to produce the sweet, unblemished fruits demanded by the top-paying markets. As noted, pepino is already an established crop in New Zealand. In the United States, it is grown on a small scale in Hawaii and California, where several hundred hectares are now under commercial cultivation. This seems to be the beginning of a promising new addition to the horticultural resources of much of the temperate zones.

OCR for page 296
Page 299 ~ enlarge ~ The pepino has been called “a decadent fruit for the '90s.” It is sweet, succulent, and melts in the mouth. (Frieda's Finest) USES The pepino is so versatile that it can be a component of any part of a meal: refreshment, appetizer, entree, or dessert. South Americans and Japanese eat it almost exclusively as a fresh dessert. It is highly suited to culinary experimentation. For instance, New Zealanders have served it with soups, seafood, sauces, prosciutto, meats, fish, fruit salads, and desserts. The fruits can also be frozen, jellied, dried, canned, or bottled. Pepinos are often peeled because the skin of some varieties has a disagreeable flavor. It pulls off easily, however. The number of seeds depends on the cultivar, but even when present, the seeds are soft, tiny, and edible, and because they occur in a cluster at the center of the fruit they are easily removed.

OCR for page 296
Page 300 NUTRITION As a source of vitamin C, the pepino is as good as many citrus fruits, containing about 35 mg per 100 g. It also supplies a fair amount of vitamin A. Otherwise, it is 92 percent water and only 7 percent carbohydrates. The fruits are normally subacid. Levels of 10–12 Brix (sugar concentration) are common. 3 AGRONOMY All pepino cultivars are propagated vegetatively. Cuttings establish roots so easily that mist sprays or growth hormones are usually unnecessary. Tissue culture is also possible. 4 By and large, pepino is grown like its relatives, tomato and eggplant. With its natural upright habit of growth and fruiting, it may be cultivated as a free-standing bush or as a pruned crop on trellises. (Supports can be used to keep the weight of the fruit from pulling the plant to the ground.) The plant grows quickly and can flower and set fruit 4–6 months after planting. It is a perennial but is usually cultivated as an annual. Undemanding in its basic requirements, the plant has wide adaptability to altitude, latitude, and soils. When young, it is intolerant of weeds, but it later smothers any low-growing competition. Established bushes show some tolerance to drought stress, quickly recovering vegetative growth, although their yield may be depressed. In dry regions, irrigation is normally used. The plants are parthenocarpic, which means they need no pollination to set fruit. However, self-pollination or cross-pollination greatly encourages fruiting. HARVESTING AND HANDLING Pepinos are harvested when fruits have a pale yellow or cream background color (at least in the popular cultivars El Camino and Suma). Fruits left on the plant until overripe often have poor flavor. Harvesting must be done carefully because the fruits bruise easily and finger markings show up. With current varieties, the fruits on a single bush mature at different times, and several pickings are necessary throughout the warm season. Yields of 40–60 tons per hectare are not 3 Any dessert-quality fruit should be sweet, with Brix levels above 8—preferably 12 or even more. Information from S. Dawes. 4 Pepinos are easily propagated by seed, but usually the seedlings are inferior to their parents. Seedlings, however, normally differ widely from each other, which allows breeders to search for superior new strains.

OCR for page 296
Page 301 ~ enlarge ~ Auckland, New Zealand. Over the last 20 years, New Zealand horticulturists have taken up the pepino as a commercial crop and have developed it, probably to a greater extent than in any other country. Their varieties derive from clonal material, introduced from Chile (following heat treatment to remove viruses). Today, pepinos are being grown on many hectares, much of it under glass, and the fruits are shipped to North America, Japan, and Europe. In fact, since 1984, pepinos have been one of New Zealand's most lucrative fruit exports. (New Zealand Herald) uncommon, and even more may be possible under greenhouse conditions. The fruits are susceptible to chilling injury and are stored at 10–12°C. At this temperature they may keep in good condition for 4–6 weeks. (Sea freighting may be possible from many countries.) A fruit taken out of storage has a shelf life of several weeks at room temperature. LIMITATIONS The pepino is a little-studied crop, with sparse factual data or commercial field experience behind it. Particular areas of uncertainty include the following. Fruit Quality Few sweet varieties also have good horticultural and marketing qualities; the skin, although edible, is often tough and bitter; and improperly ripened fruit have a bad aftertaste.

OCR for page 296
Page 302 Lack of Adaptability The best fruit candidates are insufficiently hardy for cultivation in many cool areas and are susceptible to nematodes. High temperatures retard their growth and reduce the quality of their fruits, and drought readily kills the bushes because of their shallow roots. Horticulture Cultural conditions and plant nutrition can greatly affect fruit color, sweetness, taste, and overall quality in ways that are not yet fully understood. Fruit Set Poor fruit set is often a problem. The causes seem to include over-fertilizing, which fosters vegetative growth rather than flowering, and high temperatures, which cause the flowers to abort. 5 Pests and Diseases The plant's susceptibility to pests and diseases in regions of intensive agriculture is scarcely known. Although attacks have rarely been of economic importance, more intensive cultivation of larger areas may intensify disease and pest problems. Aphids, spider mites, and whitefly already have been serious problems in California and New Zealand. Nematodes and root rot have also been concerns. In addition, the plants have shown susceptibility to viruses. RESEARCH NEEDS Fruit Quality Research is needed to better understand the causes of the insipid flavor of many pepinos. If the flavor can be sharpened and strengthened, the crop's future will be more secure. Approaches might include analysis of the effects on flavor of different varieties, stages of picking, postharvest handling, fertilization, and perhaps the use of salt. 6 Cultivation Cropping systems have not been investigated in depth, and most commercial growers rely on tomato technology. Future agronomic research should include analysis of different cultivation practices, stress tolerance, plant nutrition and irrigation, light and temperature requirements, pollination, and methods for training and supporting the plants (such as trellising). Plant Physiology The physiological problems relating to fruit set need to be better understood. Also, a convenient method for judging ripeness, other than using fruit color, would be extremely valuable. Genetic Development Because pepino reproduces easily by seed, it can be improved readily through selection of sexual variants from cross-pollination. The mixed genetic composition (heterozygosity) 5 Hermann, 1988. 6 Tomatoes grown with saline irrigation have become a premium export of Israel because of their tangy taste.

OCR for page 296
Page 303 allows considerable range in character selection. Added to this, vegetative propagation is simple, which means that any mutant type can be perpetuated without difficulty and clonal lines established. 7 Market Development The creation of a new crop requires the development of marketing as well as horticulture. Because pepinos are new to consumers outside the Andes, markets are unstable. Furthermore, there is a lack of basic marketing knowledge, consumer acceptability is unknown, and ultimate market demand is uncertain. Promotion and market development could do much to assure the steady advancement this crop deserves. Species Information Botanical Name Solanum muricatum Aiton Family Solanaceae (nightshade family) Botanical Synonyms Solanum variegatum Ruíz and Pavón; Solanum guatemalense Hort., and others Common Names Quechua: cachun, xachun Aymara: 'kachan, kachuma Spanish: pepino, pepino dulce, pepino blanco, pepino morado, pepino redondo, pepino de fruta, pepino de agua, mataserrano, peramelon (Canary Islands) English: pepino, Peruvian pepino, pear melon, melon pear, melon shrub, tree melon, sweet cucumber, mellowfruit, “kachano” (an Aymara derivative that has been suggested to avoid confusion with melons or cucumbers) Origin. The place and time of the pepino's domestication are unknown, but the plant is native to the temperate Andean highlands. It is known only in cultivation or as an escaped plant. It is an ancient crop, and is frequently represented on pre-Columbian Peruvian pottery. Description. This highly variable species is a sprawling, perennial herb that reaches about 1 m in height, with a woody base and fibrous roots. Several stems may arise from the base, and they may establish roots where they contact soil. The leaves may be simple or compound; when compound, the number of leaflets may vary from 3 to 7. The white to pale-purple to 7 Recent studies show that even immature seed is viable if germinated in nutrient agar. Information from J.R. Martineau.

OCR for page 296
Page 304 bright-blue flowers occur in clusters. As noted, fruits can be produced without pollination (such parthenocarpic fruits are seedless), but fruit set is much greater when self- or cross-pollination occurs. Pollen is not usually abundant. As the stigma is longer than the anthers, pollination is unlikely to occur unless pollen is transferred by an insect or human hand. The fruit varies from globose to pointed oval. When ripe, the skin background color may be creamy to yellow-orange. Purple, gray, or green striping or blush colorations give the fruit distinctive appearance. The flesh may be greenish, yellow, salmon, or nearly clear. Horticultural Varieties. Pepinos appear in markets throughout the Andes, but although there are many distinct strains, few have been stabilized into named cultivars. In Chile, however, there are named varieties. All produce similar purple-striped, egg-shaped fruits. These are only slightly sweet, with a Brix rating generally less than 8. The purple stripes mask the bruise marks so common on the golden, unstriped pepinos. Chile is a major exporter, and its varieties are now also grown in California and New Zealand. In New Zealand, the most common cultivated varieties are El Camino and Suma. El Camino has medium to large egg-shaped fruit with regular purple stripes. For reasons that possibly have to do with mineral nutrients given to the plant, it sometimes produces off-flavored fruits (these are identifiable by their brownish green color). Suma is a vigorous cultivar producing heavy crops of medium to large globose fruits, with regular purple stripes and attractive appearance. Their flavor is mild and sweet. In California, New Yorker is the most widely grown cultivar. Since 1984, however, Miski Prolific has become equally popular. Its flesh is deep-salmon color, and its skin creamy white with light-purple stripes. There are a few seeds in each fruit. Environmental Requirements. Although this plant is native to equatorial latitudes, it is typically grown on sites that are cool. Thus, it is found in upland valleys, in coastal areas cooled by fog, and parts of Chile where the summers are not hot. Daylength. Since the pepino fruits well at many latitudes, it appears to be photoperiod-insensitive. Rainfall. 1,000 mm minimum, well distributed over several months. As noted, the pepino has little drought resistance, and in Chile and Peru irrigation is often used.

OCR for page 296
Page 305 Altitude. The plant seems unaffected by altitude. It grows from sea level in Chile, New Zealand, and California to 3,300 m in Colombia. Low Temperature. Once established, the plant experiences frost damage at temperatures below −3°C. Seedlings are even more sensitive. Cool, wet weather during the harvest season results in skin cracking. High Temperature. The plant performs best at 18–20°C. With adequate moisture, it can tolerate intermittent temperatures above 30°C. However, fruit production then declines, particularly if both day and night temperatures are high. Soil Type. The plant thrives in moderately moist soils with good drainage. Soils should be above pH 6.0 to avoid disorders such as manganese toxicity and iron deficiency. If soil is too fertile, there can be problems of fruit set and fruit quality. Related Species. Solanum caripense (tzimbalo) is a possible wild ancestor, which crosses readily with pepino and bears edible fruit. It is a sprawling plant, more open and smaller than the pepino, that is fairly widespread in the Andes between 800 and 3,800 m elevation. Its fruits are elongate and slightly smaller than ping-pong balls. There is, however, little flesh to eat, for they are mostly juice and seeds. Some are rather intensely flavored, sweet, and occasionally leave a bitter aftertaste. The plant's advantages are early fruiting, abundant yields, and fairly tough-skinned fruit. Solanum tabanoense is a rare plant found between 2,800 and 3,500 m in southern Colombia, Ecuador, and Peru. The fruit has an appreciable amount of flesh and is similar to the pepino in size and taste. ~ enlarge ~