Sechium edule
(chayote)

Preferred Scientific Name

• Sechium edule (Jacq.) Sw.

Preferred Common Name

• chayote

Other Scientific Names

• Chayota edulis (Jacq.) Jacq.
• Sechium americanum Poir.
• Sicyos edulis Jacq.

International Common Names

• English: alligator-pear; cho-cho; christophene; christophine; pipinella; vegetable pear
• Spanish: chay; chaya; chayote; chima; chocho; chuma; escobilla dulce; guispui; huisquil; talote
• French: chayotte; chouchou; chou-chou; chouchoute; christofine; christophine; hayotte
• Chinese: fo shou gua

Local Common Names

• Argentina: cayota
• Bolivia: cayota
• Brazil: chuchu; machiche-francês; machucho; xuxú
• Cambodia: su-suu
• Cuba: chayote blanco; chayote francés; chayote verde; chayotera; chote
• Dominican Republic: méliton; tayota; tayote
• Germany: Chayote; Schuschu
• Haiti: chayotte; concombre; mirliton
• Honduras: chinchayote; ñame; patasté; patastilla
• Indonesia: labu siam; waluh jepang
• Italy: chayote
• Laos: nooy th'ai; savëëx
• Mexico: bisquil ; camochayote; chinchayote; cueza; güisquil; huisayote; uisquil
• Papua New Guinea: choko; sako
• Philippines: hayuti ; sayote
• Puerto Rico: tallón; tallote
• Thailand: ma-kheua-kreua; taeng-kariang
• Vietnam: su su

EPPO code

• SEHED (Sechium edule)

• Domain: Eukaryota
•     Kingdom: Plantae
•         Phylum: Spermatophyta
•             Subphylum: Angiospermae
•                 Class: Dicotyledonae
•                     Order: Violales
•                         Family: Cucurbitaceae
•                             Genus: Sechium
•                                 Species: Sechium edule

The genus Sechium P. Browne had long been considered as monotypic with S. edule as the only species. Since the 1970s wider genus concepts have been proposed and Sechium is now comprises 11 species (World Flora Online, 2020). Of these, nine are only found in the wild, distributed from Mexico to Panama. One species S. tacaco is only cultivated in Costa Rica, and the other, S. edule is widely cultivated throughout the Americas and other regions of the world, with some native wild populations occurring in southern Mexico (Lira, 1996). The wild types of S. edule differ from cultivated types by their more robust growth and larger leaves, flowers and staminate inflorescence than those found in cultivated forms and the pulp of their fruits is bitter and usually more fibrous. S. compositum, occurring in southern Mexico and Guatemala, is considered the closest wild relative of S. edule. Many commercially grown cultivars with different fruit characters have been developed (Lira, 1996; Acevedo-Rodríguez, 2005; FAO, 2007; Lira et al., 2009; PROSEA, 2018).

A monoecious, vigorous, perennial herbaceous vine with a large tuberous root. Stem climbing or sprawling, longitudinally grooved, growing 10-15 m in a single season. Tendrils large, 2- to 5-branched. Leaves simple, spirally arranged; petiole 3-25 cm long; leaf-blade broadly ovate-circular in outline, 7-25 cm in diameter, base deeply cordate, 3- to 7-angular or lobed, acute, margins obtusely dentate, scabrid hairy. Inflorescences axillary racemes with small, greenish or cream, 5-merous flowers; hypanthium saucer-shaped, with 10 pouch-like nectaries on the bottom; male racemes with peduncle 6-30 cm long, 10- to 30-flowered; stamens 5, filaments united; female flowers usually solitary on short pedicels, in same axil as male; corolla ca. 2 mm in diameter; connate style and stigmas, forming a small head. Fruit a one-seeded fleshy berry, variable, commonly pear-shaped, 7-20 cm long, somewhat ribbed, smooth or shortly spiny, dark green to almost white; fruit stalk 2-3 cm long, pendent; pulp white or greenish-white. Seed solitary, ovoid to ellipsoid, 2.5-5 cm long, compressed, white, germinating within the fruit, usually while the fruit is still attached to the plant; in some genotypes seed-coat with fibres radiating into the flesh, in others obsolescent and the flesh fibreless.

Other botanical information: Chayote cultivars do not breed true, although it has been observed that cultivars do not segregate significantly from one generation to the next because of the relative isolation of chayote plants from one another when planted in home gardens. When planted together, complete panmixy can be observed. Substantial efforts made at CATIE (Costa Rica) to describe cultivars on the basis of fruit characteristics proved to be of limited relevance because of the extraordinary variability, with continuous variation in almost all the characters. The variable fruit characters include size (7-20 cm long), weight (100-1000 g), colour (continuous range from white to dark green), shape, fruit-wall features (spines, lenticels, grooves and ridges), flavour and texture. Nevertheless, farmers 'classify' the genotypes by a combination of such fruit characteristics. Instead of speaking of cultivars, it seems best to consider those types as landraces or as primitive populations. At least 25 landraces exist in Central America. Commercially grown chayote consists of two types: a medium sized, light-green, smooth, pear-shaped fruit and a small, white, smooth, globular one. Several types can be distinguished in South-East Asia. For example, in West Java (Indonesia) the common type is dark green and almost glabrous, but more spiny and lighter green types can be found. A complete white type, less tender and spiny, is sometimes grown as a botanical curiosity.

The center of origin and domestication of S. edule is southern Mexico. Since pre-Columbian times, the Aztecs and Mayans cultivated and spread S. edule across Mesoamerica. The European naturalist, Francisco Hernández, who lived in Mexico between 1550-1560, wrote in his journal about the different uses of chayote. After the colonization of America, S. edule spread rapidly throughout the tropics and subtropics where it is now widely cultivated and naturalized (Lira, 1996; Bisognin, 2002).

Sechium edule was apparently introduced to the Caribbean and South America between the 18^th and the 19^th centuries by European explorers. The first botanical description of S. edule was in 1756 by P. Brown, using plants collected in Jamaica. Brown also pointed out that, by that time, this species was widely cultivated throughout Jamaica (Hernández and León, 1994; Lira 1996; Bisognin, 2002; Cadena-Iñiguez et al., 2007). In Puerto Rico, S. edule was first reported as naturalized in 1881 (Rojas-Sandoval and Acevedo-Rodríguez, 2015). During the 18^th and the 19^th centuries, S. edule was also introduced into Europe from whence it was taken to Africa, Asia and Australia. Its introduction into the United States and Hawaii dates from the late 19^th century (Hernández and León, 1994, Lira 1996; Cadena-Iñiguez et al., 2007). In New Zealand, it was first reported as naturalized in 1989 (NZPCN, 2018).

Category	Sub-Category	Habitat	Presence	Status
Terrestrial	Managed	Cultivated / agricultural land	Present, no further details	Harmful (pest or invasive)
Terrestrial	Managed	Cultivated / agricultural land	Present, no further details	Natural
Terrestrial	Managed	Cultivated / agricultural land	Present, no further details	Productive/non-natural
Terrestrial	Managed	Disturbed areas	Present, no further details	Harmful (pest or invasive)
Terrestrial	Managed	Disturbed areas	Present, no further details	Natural
Terrestrial	Managed	Disturbed areas	Present, no further details	Productive/non-natural
Terrestrial	Managed	Urban / peri-urban areas	Present, no further details	Harmful (pest or invasive)
Terrestrial	Managed	Urban / peri-urban areas	Present, no further details	Natural
Terrestrial	Managed	Urban / peri-urban areas	Present, no further details	Productive/non-natural
Terrestrial	Natural / Semi-natural	Natural forests	Present, no further details	Harmful (pest or invasive)
Terrestrial	Natural / Semi-natural	Natural forests	Present, no further details	Natural
Terrestrial	Natural / Semi-natural	Natural forests	Present, no further details	Productive/non-natural
Terrestrial	Natural / Semi-natural	Natural grasslands	Present, no further details	Harmful (pest or invasive)
Terrestrial	Natural / Semi-natural	Natural grasslands	Present, no further details	Natural
Terrestrial	Natural / Semi-natural	Natural grasslands	Present, no further details	Productive/non-natural
Terrestrial	Natural / Semi-natural	Riverbanks	Present, no further details	Harmful (pest or invasive)
Terrestrial	Natural / Semi-natural	Riverbanks	Present, no further details	Natural
Terrestrial	Natural / Semi-natural	Riverbanks	Present, no further details	Productive/non-natural

Bimodal
Summer
Uniform
Winter

Soil drainage

• free

Soil reaction

• acid
• alkaline
• neutral

Soil texture

• heavy
• light
• medium

Natural Dispersal

Sechium edule spreads by seeds. In wild types, seeds germinate asynchronously after the fruits fall to the ground. In cultivation, the seed germinates in the ripe fruit while still on the mother plant. The stem of the seedling grows out from the fruit apex and produces roots when it contacts the ground (Hernández and León, 1994; Cadena-Iñiguez et al., 2007; PROSEA, 2018; PROTA, 2018).

Intentional Introduction

Sechium edule has been intentionally introduced for human consumption across tropical and subtropical regions. The fruits, tubers, seeds and young shoots are edible. Propagation is by seed (PROSEA, 2018; USDA-ARS, 2018).

Sechium edule is a vine that has escaped from cultivation and can be found naturalized in abandoned agricultural lands and disturbed sites near villages and roadsides. Under favorable environmental conditions, it grows copiously and can form dense colonies that outcompete native plant for light, nutrients and water. The climbing stems may be several metres in length and may ascend high into the canopy, engulfing native vegetation and diminishing the light intensity and thus the photosynthetic capacity of trees and understory plants. It may also inhibit the germination and establishment of seedlings in the understory, changing the natural regeneration and composition and structure of invaded forests. S. edule can also suffocate and break down trees and shrubs that support it due to its heavy weight. It also hosts viruses and insects that affect other plants and crops (Lira, 1996; Acevedo-Rodríguez, 2005; FAO, 2007; Oviedo and Gonzalez-Oliva, 2015; Rojas-Sandoval and Acevedo-Rodríguez, 2015; ISSG, 2018; I3N-Brasil, 2018; PIER, 2018; PROSEA, 2018; PROTA, 2018).

Invasiveness

• Proved invasive outside its native range
• Highly adaptable to different environments
• Is a habitat generalist
• Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
• Pioneering in disturbed areas
• Highly mobile locally
• Benefits from human association (i.e. it is a human commensal)
• Long lived
• Fast growing
• Gregarious

Impact outcomes

• Ecosystem change/ habitat alteration
• Host damage
• Modification of successional patterns
• Monoculture formation
• Reduced native biodiversity
• Threat to/ loss of native species

Impact mechanisms

• Competition - monopolizing resources
• Competition - shading
• Competition - smothering
• Competition - strangling
• Pest and disease transmission
• Rapid growth

Likelihood of entry/control

• Highly likely to be transported internationally deliberately

Economic value

Sechium edule is an important commercial vegetable. Currently, Mexico, Costa Rica, Brazil and Dominican Republic are leading exporters and the demand for this vegetable is steadily increasing in the United States, Canada and Europe. It is also an important crop in developing countries as a cheap, easy-to-produce vegetable, both for home consumption and for city markets (Cadena-Iñiguez et al., 2007; FAO, 2007).

Social Benefit

Every part of S. edule is useful, but it is mainly grown as a fruit vegetable. It is widely cultivated for its edible fruits, tubers and young shoots. The fruits vary in flavour, according to cultivar, from bland to sweetish or starchy. The fruits are usually boiled and then prepared in a number of ways (e.g. fried, baked, creamed). They can also be made into pickles. The fruits of the bland cultivars are also used industrially as a food filler for pastes and sauces and as a substitute for apple in pies and tarts. The large flat seed has a nut like flavour and is generally cooked and served with the rest of the fruit or is removed for use alone as a table delicacy. The starchy underground tubers are cooked and eaten similarly to potatoes and are also candied.. The tender young shoots are cooked and eaten as a vegetable, and are especially rich in vitamins A and C, the B vitamins, calcium and iron. It is one of the most important greens in Papua New Guinea. Because of its low energy value, chayote is gaining importance as a dietary food in hospitals and nursing homes. Chayote fruits are also considered good baby food. Fruits, shoots and tubers are also used as fodder for pigs, poultry and cattle (Lira, 1996; FAO, 2007; Flora of Panama, 2018; PROSEA, 2018; PROTA, 2018).

The fibres from the stem have been used to make baskets and hats and as binding material in the construction of mud houses. During the 19^th and early 20^th centuries, Réunion had an important home industry of hats and other artefacts made from these attractive fibers, called ‘paille de chouchou’. S. edule is also a food plant for honey-producing bees (stingless bees and honey bees). It is loved by beekeepers because it flowers abundantly throughout the year (Hernández and León, 1994; Lira 1996; FAO, 2007; PROTA, 2018). . In Java the plant is used to shade fish ponds, and in the Philippines it has undergone trials for use in erosion control.

The leaves and tubers are used in traditional medicine, mostly across Latin America and the Caribbean region, but also in Asia. The leaves apparently have cardiovascular modifying as well as blood pressure lowering properties. They are also used to dissolve kidney stones. The tubers are a potent diuretic and are also applied for pulmonary ailments and relief of intestinal inflammation (Lira, 1996; FAO, 2007; PROSEA, 2018).

Literature
Engels JMM, 1983. Variation in Sechium edule Sw. in Central America. Journal of the American Society for Horticultural Science 108:706-710.
Engels JMM, 1984. Chayote: a little known Central American crop. FAO/IBPGR Plant Genetic Resources Newsletter 63:2-5.

Herklots GAC, 1972. Vegetables in South-East Asia. George Allen & Unwin, London, United Kingdom:339-342.

Newstrom LE,1985. Collection of chayote and its wild relatives. FAO/IBPGR Plant Genetic Resources Newsletter 64:14-20.

Newstrom LE, 1986. Studies on the origin and evolution of chayote. Thesis, University of California, Berkeley, United States.

Newstrom LE, 1989. Reproductive biology and evolution of the cultivated chayote (Sechium edule, Cucurbitaceae). In: Bock GH & Linhart YB eds.: The evolutionary ecology of plants. Westview Press, Boulder, San Francisco/London, United States/United Kingdom:491-509.

Whitaker TW & Davis GN, 1962. Cucurbits:botany, cultivation and utilization. Leonard Hill, London, United Kingdom.