Tomatillo

Thetomatillo(Physalis philadelphicaandPhysalis ixocarpa), also known as theMexican husk tomato, is a plant of thenightshadefamily bearing small, spherical, and green or green-purple fruit of the same name.Tomatillos originated inMexicoand were cultivated in thepre-Columbian era.A staple ofMexican cuisine, they are eaten raw and cooked in a variety of dishes, particularlysalsa verde. The tomatillo is aperennial plant, but is generally grown for agriculture each year as if it were anannual.
The tomatillo (fromNahuatl,tomatl)is also known as husk tomato,Mexican groundcherry,large-flowered tomatillo,or Mexican husk tomato.Some of these names, however, can also refer to other species in the genusPhysalis.Other names are Mexican green tomato and miltomate.
InSpanish, it is calledtomate de cáscara(husk tomato),tomate de fresadilla(little strawberry tomato),tomate milpero(field tomato),tomate verde(green tomato),tomatillo(Mexico; this term means "littletomato" elsewhere),miltomate(Mexico,Guatemala),farolito(little lantern), or simplytomate(in which case the tomato is calledjitomatefrom Nahuatlxitomatl).
The tomatillo genus namePhysalisis from New Latinphysalis, coined by Linnaeus from Ancient Greek φυσαλλίς (physallís, "bladder, wind instrument"), itself from φυσιόω (physióō, "to puff up, blow up"),φυσώ(physṓ).
Ixocarpa means "slimy fruit", referencing a sticky or slimy coat often on a tomatillo before it ruptures from thecalyx.
Tomatillos are native toCentral AmericaandMexico, having a wild growth range from Mexico toCosta Rica.The plant is grown mostly in the Mexican states ofHidalgoandMorelos, and in the highlands ofGuatemalawhere it is known asmiltomate. In the United States, tomatillos have been cultivated since 1863, with one dubbed "jamberry" in 1945 and others with the names "Mayan husk tomato" and "jumbo husk tomato".Further distribution occurred in theBahamas,Puerto Rico,Jamaica, andFlorida.By the middle of the 20th century, the plant was further exported toIndia,Australia,South Africa, andKenya.
The wild tomatillo and related plants are found everywhere in the Americas except in the far north, with the highest diversity in Mexico. In 2017, scientists reported on their discovery and analysis ofPhysalis infinemundi, a fossilPhysalisfound in thePatagonianregion of Argentina, dated to 52 million yearsBP. The finding has pushed back the earliest appearance of theSolanaceaeplant family and thePhysalisgenus of which the tomatillo is a part.
Tomatillos were domesticated in Mexico before the coming of Europeans and played an important part in the culture of theMayaand theAztecs, more important than thetomato.Thespecific namephiladelphicadates to the 18th century.
There is limited information about tomatillo production,even though tomatillos are distributed and grown worldwide as a home-grown garden plant. Tomatillos are mainly cultivated in outdoor fields inMexicoandGuatemalaon a large scale. Smaller crops are planted in many parts of the United States.In Mexico, tomatillos are planted within a wide range of altitudes.
In general, tomatillo plants are tolerant to many different soil conditions. However, they do best in well-drained, sandy, fertile soil conditions with apHbetween 5.5 and 7.3.Tomatillo plants arecold sensitive.They grow best at 25 to 32 °C (77 to 90 °F). Below 16 °C (61 °F), growth is very poor.Tomatillo plants prefer full sun exposure and warm locations.
Transplanting is the most common practice for planting tomatillo plants.Transplants are produced in greenhouses or transplant beds.Germination occurs at 20 to 27 °C (68 to 81 °F).Transplanting occurs 6 to 8 weeks after seeding and when the risk of frost is past. Transplants produced indoors need to harden off in a warm, sunny place for a few days before being planted outside.Direct outdoor seeding can only be done if no frost risk exists and soil temperature is higher than 15 °C (59 °F). Direct outdoor seeding leads to the shortening of the vegetation period.Due to its branching growing pattern, a single plant requires sufficient growing space. Tomatillos are typically grown in rows 0.7 to 1.6 m (2 ft 4 in to 5 ft 3 in) apart.Although tomatillo is aperennial plant, overwintering is difficult, so it is normally cultivated as an annual plant.
Tomatillo plants can reach heights of1.5 to 2 meters (5 to6+1⁄2ft).Due to their rapid and branching growth, it is recommended to stake them. Staking also facilitates later harvesting and prevents the fruit from touching the ground, which reduces damage to fruit and husk.Staking can also reduce disease and slug damage.Fertilization is recommended at a moderate level. An application of 40–90 kg/ha (36–80 lb/acre) ofphosphorusis common. Other nutrients and fertilizers (N/ K) may be required depending on soil type and irrigation.For non-commercial production, regular fertilization is recommended. Although tomatillo plants become more drought-tolerant as they age, regular watering is required.Tomatillo plants require25–38 mm (1–1+1⁄2in) of water per week.Water can come from rainfall or irrigation. Irrigation can be managed by drip, sprinkler, furrow, or watering can.Irrigation frequency depends on weather and the crop's growth stage, ranging from once or twice a week to daily during hot weather.Weeds are a serious challenge in tomatillo production and are especially important during the first few weeks. Plastic and organic mulches help to control weeds effectively.Applications of plastic mulches also help to restrict soil water evaporation and modifymicroclimate,thereby affecting tomatillo growth and yield.
Tomatillos are harvested when the fruits fill the calyx.This state is normally achieved 65 to 100 days after transplanting.Fruit production continues for 1 to 2 months or until the first frost. Harvesting occurs regularly, typically every day, and is done by hand. A plant produces 60 to 200 fruits within a single growing season, with an average yield of about 20 tonnes per hectare (9 short tons per acre).Tomatillos can be stored for up to three weeks in a cold and humid environment.
Tomatillos can be harvested at different stages of ripeness. Forsalsa verde, harvesting may be done early when the fruit is sour with a light flavor. Tomatillos can be picked later when the fruits are seedier for a sweeter taste.Tomatillos have diverse uses in stews, soups, salads,curries,stirfries, baking, cooking with meats,marmalade, and desserts.
Tomatillos are a key ingredient in fresh and cooked Mexican and Central-Americangreen sauces. The green color and tart flavor are the main culinary contributions of the fruit. Purple and red-ripening cultivars often have a slight sweetness, unlike the green- and yellow-ripening cultivars, so they generally are used in jams and preserves. Like their close relative, theCape gooseberry, tomatillos have a highpectincontent. Another characteristic is that they tend to have a varying degree of a sappy, sticky coating, mostly when used on the green side out of the husk.
Ripe tomatillos keep refrigerated for about two weeks. They keep longer with the husks removed and the fruit refrigerated in sealed plastic bags.They may also be frozen whole or sliced.
Tomatillos can also be dried to enhance the sweetness of the fruit in a way similar to driedcranberries, with a hint of tomato flavor.The tomatillo flavor is used infusion cuisinesfor blending flavors from Latin American dishes with those of Europe and North America.
P. ixocarpais often confused withP. philadelphicadue to morphological similarities and the fact that neither species have had a cleartype designation.Physalis ixocarpaandPhysalis philadelphicahave blue anthers that twist after opening, a yellow corolla with five blue-tinged spots or smudges, and a 10-ribbed calyx filled or burst by the berry. The two species differ in flower size and stigma type.
P. philadelphicagrow up to 15 to 60 cm (6 to 24 in) and have few hairs on the stem. The leaves have acute and irregularly separated dents on the side.They are typically about one meter (3 ft) in height, and can be either compact and upright orprostratewith a wider, less dense canopy. The leaves are typically serrated and can be either smooth orpubescent.
The tomatillo is a member of the genusPhysalis, erected byCarl Linnaeusin 1753.Jean-Baptiste de Lamarckdescribed the tomatillo under the namePhyslis philadelphicain 1786. Other species, such asP. aeuataandP. violaceawere described later. The tomatillo is also often classified asP. ixocarpaBrot.However,P. philadelphicais the most important species economically.The nomenclature forPhysalishas changed since the 1950s.P. philadelphicawas at one time classified as a variety ofP. ixocarpa. Later, the classification ofP. ixocarpawas revised under the species ofP. philadelphica. Today, the nameP. ixocarpais commonly used for the domestic plant andP. philadelphicafor the wild one.
Flowers come in several colors: white, light green, bright yellow, and sometimes purple. Flowers may or may not have purple spots toward the center of thecorolla. Theanthersare typically dark purple to pale blue. Tomatillo plants are highlyself-incompatible, and two or more plants are needed for properpollination. Thus, isolated tomatillo plants rarely set fruit.
The tomatillo fruit is surrounded by an inedible, paper-likehuskformed from thecalyx.As the fruit matures, it fills the husk and can split it open by harvest time. The husk turns brown, and the fruit can be ripe in several colors, including yellow, green, or even purple. The freshness and greenness of the husk are quality criteria.
There are several varieties of tomatillos, with differences in tastes, traits, and ripening colors.Somecultivarsinclude Amarylla, Chupon, Gigante, Green Husk, Mexican, Pineapple, Purple de Milpa, Rio Grande Verde, and Yellow.
Although self-compatibility is common among wild populations, tomatillos carryself-incompatibletraits. The plant, i.e., the fertilehermaphrodite, is not able to produce zygotes afterself-pollinationoccurs.This limits the ability to improve tomatillo production regarding the seed quality and the production of varieties.
The self-compatibility gene is situated in thechromosomesof the tomatillo and is not inherited throughcytoplasm. Onlyheterozygousplants can be self-compatible as the trait is controlled by adominant gene.Tomatillo can thus produce seeds throughself-pollinationdue to the involvement of self-compatibility traits, but the germination viability is different throughout the produced seeds. This suggests that not only incompatible pollen is involved but also inviability at the seedling stage.A study in 2022 using a commercial cultivar found that it was self-compatible and demonstrated incompatibility only in some of the inter-specific hybrid pollinations that were attempted.
Tomatillo is generally a resistant crop as long as its climatic requirements are met. However, as with all crops, mass production brings exposure to pests and diseases. As of 2017, two diseases affecting tomatillos have been documented, namelytomato yellow leaf curl virusandturnip mosaic virus. Symptoms of tomato yellow leaf curl virus, including chlorotic margins andinterveinalyellowing, were found in several tomato and tomatillo crops in Mexico and Guatemala in 2006.After laboratory tests, the virus was confirmed. Symptomatic plants were associated with the presence ofwhiteflies, which were likely the cause of this outbreak.
Turnip mosaic virus was discovered in several tomatillo crops in California in 2011, rendering 2% of commercially grown tomatillo plants unmarketable, with severe stunting and leaf distortion.Thegreen peach aphidis a common pest in California, and since it readily transmits the turnip mosaic virus, this could be a threat to tomatillo production in California.