marsh VI 29 Photos by Toni Siebert, CVC, 5/22/2008. Photo rights . C-35 left, Carrizo right, 25 year old trees. Source: Received as seed by H.B. Frost and this accession is one of the nucellar seedlings, 1915. Parentage/origins: Marsh grapefruit originated as a chance seedling around 1860 in Lakeland, Florida. Because it was the first seedless variety to be promoted, it soon became the most widely planted grapefruit variety. Rootstocks of accession: Carrizo citrange, C-35 citrange Season of ripeness at Riverside: January to May Notes and observations: OJB: The tree grows vigorously to a large size. The fruit is almost round in shape with a smooth light yellow rind. The flesh is pale yellow, juicy, and tender, with a good flavor. To achieve acceptable quality, Marsh grapefruit must be grown in locations that satisfy its high heat requirement. The fruit is late maturing and holds well on the tree. Description from The Citrus Industry Vol.

1 (1967) : "This variety is a nucellar seedling of Marsh that was derived by H. B. Frost of the University of California Citrus Research Center, Riverside, from seed planted in 1916. It was introduced commercially in 1952. Currently, it is the principal clonal selection of Marsh under propagation in California and South Africa." "Fruit medium in size, oblate to spherical; areole ring indistinct or lacking; seeds few or none. Color pale to light yellow at maturity. Rind medium-thin, tough; surface very smooth and even. Flesh buff-colored; tender, very juicy; flavor good though not so pronounced as in some seedy varieties. Holds unusually well on the tree and ships and stores well. The latest-maturing of all commercial varieties. Tree vigorous, spreading, large, and productive. Because of high heat requirements, commercially restricted to very hot climates. According to Webber (1943), Marsh apparently originated as a chance seedling planted about 1860 on a farm near Lakeland, Florida.

Its commercial value as a seedless variety was not recognized until 1886, however, when it was brought to the attention of E. H. Tison of the Lakeland Nursery Company, who immediately arranged for its propagation and introduced it soon thereafter as a choice seedless variety. A few years later it was given its present name by C. M. Marsh, who had acquired the Lakeland Nursery. According to Mr. Tison, the owner of the farm on which the parent tree occurred insisted that it developed as a root sprout from an old seedling tree which produced seedy fruit. While this is possible, it seems highly improbable. Primarily because of its comparative seedlessness, within a few years after its introduction Marsh became the variety most planted in Florida and virtually the only variety planted elsewhere. It is still by far the leading variety and is worldwide in its distribution. Marsh is of unusual horticultural interest not only because it was the first seedless grapefruit variety discovered but also because the pigmented varieties currently of greatest commercial importance trace back to it. Thus, Thompson (Pink Marsh) originated as a limb sport of Marsh and Redblush (Ruby) or Red Marsh occurred as a bud mutation of Thompson.

On the other hand, Marsh has also given rise to inferior bud variations, frequently characterized by a reversion to seediness. Other seedless varieties of more recent origin, virtually indistinguishable from Marsh, include Cecily of South Africa and Davis. Nucellar clonal budlines are currently of importance in Texas, Arizona and California, principal among which are Frost, CES (Citrus Experiment Station, Riverside, California), and USDA (U.S. Date and Citrus Station, Indio, California). Reed, a seedling that originated in the dooryard of J. F. Reed of Taft, California, is one of the most recent selections to receive attention." Availability: Commercially available in California through the Citrus Clonal Protection Program . Vegetarians in Paradise/Grapefruit History/Grapefruit Nutrition/Grapefruit Folklore/GrapefruitRecipe The grapefruit, not even 300 years old, is just a kid in the world of fruits. The offspring of the pummelo, sometimes spelled pomelo and even known as shaddock, the grapefruit may have appeared as a horticultural accident during the 1700s in Jamaica.

The grapefruit might never have made a debut at all if it hadn't been for Captain Shaddock, a 17th century English ship commander who brought seeds of the pummelo from the East Indies and delivered them to the West Indies in 1693. Another theory is that the grapefruit may have been a cross between the pummelo and an orange, though no records of a deliberate hybridization exist. In either case, the pummelo, that is native to Malaysia and Indonesia, seems to have fathered the grapefruit that began as a smaller fruit than our familiar grapefruit and was actually about the size of an orange. By 1750 it was known in Barbados as the "forbidden fruit," a name that traveled to Jamaica by 1789. There the grapefruit was also called the "smaller shaddock" after Captain Shaddock. In his book In Search of the Golden Apple, USDA citrus scientist William C. Cooper describes grapefruit and sweet oranges growing wild on many islands of the West Indies. While researching in Haiti, he noticed a citrus fruit resembling the grapefruit, but called chadique that was flourishing in the mountains.

In Jamaica the grapefruit was not a popular fruit because of its bitter, acidic flavor. However, the Jamaican ugli, a hybrid of the grapefruit and the tangerine that appeared in the early 1900's, is favored for its appealing sweet flavor and juiciness. Somewhat resembling the grapefruit, the ugli suffers image problems. Its unattractive skin is thick and wrinkled, and it is oddly shaped out of round with a flat bottom. The ugli varies in color from mottled deep green to greenish yellow and sometimes even yellow orange. A French botanist, the Chevalier de Tussac, wrote in his notes in 1820: "I have had the occasion to observe, at Jamaica, in the botanical garden of the Government, a variety of shaddock whose fruits, which are not bigger than a fair orange, are disposed in clusters; the English in Jamaica call this the 'forbidden fruit' or 'smaller shaddock.' The grapefruit first appeared in the U.S. in 1823 when Count Odette Phillipe brought the seeds from the Bahamas to Safety Harbor near Tampa, Florida.

Like so many other foods introduced into the United Sates from distant countries, the grapefruit did not gain immediate popularity. One American gardening encyclopedia referred to grapefruit as "thick-skinned and worthless." The seeds from those first plants thrived and produced fruit. The neighborhood received a gift of the seeds from those grapefruits, launching the first cultivation of grapefruit in that region. By 1840, grapefruit was stirring some minor interest. One day in the year 1870 John A. MacDonald noticed an unusual tree near his home in Orange County, Florida. The large clusters of golden fruits were so appealing he bought them all. Soon after, he established the first grapefruit nursery from the seeds of that tree. In 1885, Florida's first shipment of grapefruits to New York and Philadelphia created a flurry of interest in the fruit and was the beginning of a serious commercial grapefruit industry. By the late 1800's grapefruit trees were popping up in unlikely locales like the southern part of Texas where it was thought too cold for citrus to survive. One very determined grapefruit tree froze to the ground during a very cold Texas winter but survived to produce fruit.

After freezing many winters, the tree proved to be a survivor and lived to produce fruit repeatedly. Florida developed into a major commercial center with its burgeoning grapefruit crop of Duncan and Marsh varieties. The Duncan, whose ancestor was a seed planted by Count Phillipe, is a flavorful but seedy grapefruit most used for canning. Because they discolor, pink grapefruits are not used for canning. The Marsh may have been a chance seedless variety and was developed in the 1860's by a nurseryman named C.M. Marsh. As early as 1910 farmers were successfully growing grapefruits in the Rio Grande Valley of Texas, and in Arizona and California. However, during the 1940's grapefruit became a household favorite across the U.S. Canned grapefruit sections, grapefruit juice, and fresh grapefruit were not only shipped throughout the country, but also exported. During this era Jamaica, Trinidad, South America and Israel ventured into grapefruit cultivation. New grapefruit varieties, including those with pink and red flesh, were developed in the early 1900's and became a popular commodity in the northern states.

In 1929 a Texas citrus grower marveled at the red grapefruit growing on a tree that was producing pink grapefruits. That mutation became a new cultivar named Ruby Red that was the first grapefruit granted a U.S. patent. That Texas Red became the official state fruit of Texas in 1993. As its popularity grew, grapefruit could be found in Mexico, Argentina, Cyprus, and Morocco. Today Mexico exports grapefruits to the United States, Canada and Japan. In the Orient, where the pummelo reigns, grapefruit is a minor crop. Central Americans consider grapefruit too acidic, preferring their sweet tropical pineapples, papayas, and melons. Presently, the United States produces 41 percent of the world's grapefruit and consumes more than other countries. Florida, the state where grapefruit was first grown, is still the largest producer with Texas following close behind. California and Arizona also have thriving commercial grapefruit orchards. Commercial growers focus on developing fruits that are larger, more uniform in size, and with attractive color. Unfortunately, flavor is sacrificed for appearance.

The heirloom varieties were far tastier than today's new cultivars but are only used for canning grapefruit juice. Reverend Griffith Hughes came upon the grapefruit in 1750 and called it the "forbidden fruit" when he and others were seeking the origin of the tree of good and evil in the Garden of Eden. The grapefruit carried the "forbidden fruit" name for many years after. Originally named Citrus paradisi Macf., the grapefruit was considered a sport of the pummelo, the giant of the citrus family. Botanically, a sport is a dramatic variation of the normal variety resulting from a mutation. James MacFayden, a botanist, differentiated the grapefruit from the pummelo in his 1837 work Flora of Jamaica. More than 100 years later in 1948 citrus horticulturists began to examine the grapefruit's botanical origins and concluded it was not a sport of the pummelo but a hybrid between the pummelo and the orange that occurred accidentally. The grapefruit now has the scientific name Citrus X paradisi.

The grapefruit's common name probably came from the 19th century naturalist who noted that the fruits appeared to grow in clusters like grapes. He was observing those fist-sized fruits that grew from seeds brought to the West Indies by Captain Shaddock. Several attempts to change the grapefruit's name to something more appealing were unsuccessful. American horticulturists, convinced the grapefruit's name was unfitting, wanted to call it pomelo, but some people suggested it would be confused with pummelo. Then as recently as 1962, the Florida Citrus Mutual attempted to give the grapefruit a name that would be more commercially appealing and increase its marketability. This effort, too, failed because of public outcry. The grapefruit is still a grapefruit. Some Dutch people refer to the grapefruit as a shaddock, others call it a pampelmoose, a name originally given to a pomelo but now used for grapefruit. The French call grapefruit pamplemousse (pumpkin-sized citron). The Italians named it pompelmo.

The highly publicized grapefruit diet of the 1970's claimed that a person could lose 10 pounds (4.5 kg) in 12 days by consuming either one-half grapefruit or eight ounces of grapefruit juice with every meal. Grapefruit, because of its enzymes, was said to literally burn fat away, yet no scientific evidence has proved this claim. The U.S. stock market crash of 1929 and the following years of depression were the catalyst for introducing the grapefruit to destitute families across the country. Grapefruit, along with other citrus fruits, could be had for free with orange food stamps from the welfare board. Families encountering the fruit for the first time weren't quite sure whether it was to be cooked or eaten raw. The welfare board received frequent complaints that the families had cooked the grapefruit for several hours and still found it too tough to eat. Aroma-therapists turn to the essential oil of the grapefruit for its uplifting and reviving qualities. Used to scent a room, grapefruit oil creates a relaxed and happy environment and can relieve stress and nervous exhaustion. Grapefruit oil is said to balance the emotions.

When grapefruit became popular in the U.S., most households owned a set of grapefruit spoons that were provided whenever grapefruit halves was served. The utensils had pointed tips and serrated edges for separating the flesh from the membranes. During the '30's, '40's, and '50's half of a grapefruit frequently appeared as a breakfast favorite, its sections loosened by a special knife with a serrated, curved blade. Topping the grapefruit was a spoonful of honey or sugar and sometimes a dash of cinnamon, nutmeg, or cloves. A popular salad included grapefruit and orange sections tossed with lettuce and onion rings and dressed with a French, poppyseed, or honey-mustard dressing. During the '50's and '60's the fruit cup of canned grapefruit and orange sections in sweet syrup served with a maraschino cherry on top became the cliché of the day. Dinner at fancy restaurants and elegant weddings often began with the syrupy citrus fruit cup. Colorful Jello molds were a must on every buffet or smorgasbord table. Many molds featured yellow, orange, or green Jello with chopped grapefruit and orange sections imbedded.

Broiled grapefruit topped with sweetener was popular as a starter as well as a dessert. The English enjoy grapefruit marmalade, while confectioners prepare candied grapefruit peel. Because grapefruits are well endowed with juicy pulp, squeezing the fruit into juice was a natural that began when grapefruit became popular from the '30's on. A glass of grapefruit juice at breakfast still offers delightful refreshment. Even today, diners would feel that something was missing if a breakfast buffet didn't include pitchers of grapefruit and orange juice. Culinary enthusiasts flavored vinegar with grapefruit juice. For the imbibers, there is grapefruit wine, grapefruit beer, and grapefruit liqueur. Forbidden Fruit is a potent, cognac-based grapefruit liqueur made with sweet oranges and sweetened with honey. The liqueur has a hint of bitter undertone and is often blended with fruit juices, gin, vodka, rum, or brandy. Also available is Pink Grapefruit Liqueur. The process of making grapefruit beer begins with six peeled and sliced grapefruits combined with three gallons of hot water in a large crockpot. Cool and add 12 ounces of yeast.

Seal the crock and allow it to ferment. Bottle it immediately after fermentation and drink. The oil extracted from grapefruit peel is used as a flavoring agent in soft drinks and as an enhancement in reconstituted grapefruit juice. After bleaching and refining, grapefruit seed oil is used as mild, unsaturated oil for cooking, though it is uncommon and difficult to locate. Hardly any portion of the grapefruit goes to waste. What is considered waste matter from grapefruit packing stations is transformed into molasses and fed to cattle. After extracting oil from the seed hulls, the hulls are used by farmers as a natural soil conditioner. Sometimes the hulls are combined with dried grapefruit pulp and fed to cattle. Every part of the grapefruit is recognized for its many health benefits. Grapefruit seed extract, available in health food stores, is commonly used as an anti-fungal remedy. An infusion prepared from grapefruit flower blossoms becomes a treatment for insomnia. The beverage is also valued as a cardiac tonic. Grapefruit stimulates the digestive tract and aids in relieving indigestion and gas. The fruit also has diuretic properties helpful to people with water retention and liver and gall bladder conditions.

Rubbed on the skin, grapefruit is beneficial in treating acne and oily skin. Grapefruit pulp, because of its acidic nature, is an effective treatment for urinary infections. An extract drawn from the leaves of the grapefruit tree contains antibiotic properties. Pectin contained in the grapefruit rind and the membranes clinging to the grapefruit sections is effective in lowering serum cholesterol. Medical Warning: Some medications interact with grapefruit and grapefruit juice, causing the medication to become more intense. Check with your physician or pharmacist to make sure grapefruit will not affect your medications. To be on the safe side while taking medications, drink other fruit or citrus juices. Most will provide plenty of vitamins and minerals. While you are taking medications, read beverage labels carefully to be sure juice combinations do not contain grapefruit. Officially named Citrus X paradisi by 1830, grapefruit, which only had white flesh at that time, was established as its own citrus species. The grapefruit varieties are divided into two main categories--the white and the red. Florida developed the white Marsh, a seedless grapefruit, while Texas bred the pink and red varieties (C. reticulata). Red Blush and Ruby Red were developed from the Marsh.

Ruby Red and Red Blush can be recognized by the hint of red blush on the bright yellow skin. The flesh of the pink grapefruit varies from pale pink to intense reddish tones, depending on the season and differences in soil condition. The many common varieties have developed from these two main categories. While the Marsh is considered a seedless grapefruit, it does actually contain a few seeds. The term seedless refers to those grapefruits that produce five seeds or less per fruit. Popular varieties grown today include Duncan, Foster, Marsh, Oroblanco, Paradise Navel, Redblush, Star Ruby, Rio Red, Ruby Sweet, Sweetie, Thompson, and Triumph. The flesh of the grapefruit is similar to that of the orange, with individual sections joined by a thick, somewhat fibrous, edible membrane. Fruits average about 5 to 6 inches (12.5 to 15 cm) in diameter. The grapefruit begins to bear fruit four to six years after planting and can produce up to 30 or 40 fruits on a single branch. A single tree, in a productive year, can generate 1300 to 1500 pounds of fruit.

Most grapefruit trees grow about15 to 20 feet in height (4.5 to 6 m) though some can grow to 45 feet (13.7 m) when very old. The tree, an evergreen, is attractive with a rounded top and branches that spread horizontally. Overall, the tree has a rounded appearance with darker leaves at the top and lighter leaves on the lower branches. When the tree is in full fruit, the branches nearly touch the ground. Fragrant grapefruit blossoms appear in the spring. The closed buds are white with a green tint and open into white, four-petaled flowers that may be single or in clusters. The grapefruit itself, depending on the variety, is round, pear-shaped, or oblate (basically round but flattened at the top and bottom). The skin of the fruit is a pale lemony color though sometimes has a delicate pink tint. Its texture may be smooth or rough and slightly bumpy and has a characteristic thickness of about 3/8-inch (1 cm). Between the outer skin and the fruit inside is a white pithy layer that has a somewhat bitter flavor. While some varieties are seedless, others bear many seeds.

The fruit inside is juicy and varies in color and flavor depending on variety. Whether the flavor is sweet or tart, grapefruit has a distinctive, sometimes astringent and slightly bitter overtone. Some varieties are mildly sweet, while others are intensely sweet. Some grapefruits have white flesh inside, some delicately pink, while others, known as "ruby reds" appear intensely red. Climate plays a significant role in the length of maturity and the level of acidity of the grapefruit. In cooler, temperate zones grapefruit matures in about 13 months compared to 7 or 8 months in warmer regions. Grapefruits grown in hot tropical climates have a lower acidic level than those cultivated in cooler regions. Florida grapefruit is known for its superior flavor owed to the moist hot temperatures. Growers recognize that grapefruits with thin skins and juicy pulp are grown in a humid climate like Southern Florida. Those with thick rough skins and drier pulp are the result of drier climates such as the desert regions of Southern California. Grapefruit thrives on plenty of rain and flourishes contentedly with 36 to 44 inches (90 to 111 cm) annually. Soil requirements are varied.

Some varieties of grapefruit grow best in acidic soil, while others prefer a more alkaline environment. The U.S. Department of Agriculture, in cooperation with the Texas A & M University and Rio Farms, Inc. in Texas, conducted a program in 1946 of testing grapefruits grown on different rootstock to determine which would bring the best results. The researchers learned that soil condition and its mineral content played a significant role in successful production. Commercial growers can extend the marketing season of grapefruits by picking some mature fruits while leaving others on the tree for up to three months before harvesting. This natural method of "storing" on the tree allows those fruits to grow larger. Harvesting is accomplished by various methods. Some growers prefer to hand pick the fruits on the lower branches and use ladders to clip the stems of those higher on the tree. Because the citrus twigs are thorny, gloves and protective clothing are helpful to avoid skin scratches. Picking hooks, once popular, are seldom used today because they were found to damage many fruits Many California citrus growers employ harvesting machines that literally shake the fruits off the tree. For this method, trees must be carefully pruned to accommodate the machine that is operated by a team of three workers.

GRAPEFRUIT SECTIONS, ONE CUP (240 ml): Fresh grapefruit sections from California or Arizona, whether pink, red, or white, have about 85 calories, 1 gram of protein, and about 3 grams of fiber. Grapefruit sections from Florida have 69 to 74 calories. The carbohydrate content varies between 17 and 22 grams, while the fat content is negligible. Red and pink grapefruit shines with its approximately 596 I.U. of vitamin A. The white grapefruit is much lower in vitamin A with about 23 I.U. Grapefruit has a full range of B vitamins with the exception of vitamin B12 and contain about 28 mcg of folic acid. Grapefruit sections are a good source of vitamin C ranging from 79 to 88 mg. Grapefruit offers plenty of calcium, potassium, and magnesium as well as trace amounts of iron and zinc. The grapefruit membranes are a good source of pectin, a soluble fiber helpful in reducing cholesterol.

GRAPEFRUIT JUICE � ONE CUP (240 ml): Canned grapefruit juice has about 100 calories and 1 to 2 grams of protein. Most canned grapefruit juice is sold with the pulp removed, resulting in a loss of fiber. The carbohydrate content of the juice is similar to the grapefruit sections with 17 to 22 grams. Pink grapefruit juice supplies 1087 I.U. of vitamin A, while the white provides a minimal 25 I.U. With the exception of vitamin B12, the juice swells with B vitamins with 10 mg of thiamine, .05 mg of riboflavin, and .49 to .57 mg of niacin. Folic acid content is about 25.7 mcg, while vitamin C ranges from 72 to 93.9 mg. Calcium content varies from 17.2 to 22.3 mg, and potassium offers 378 to 400 mg. Iron and zinc are present with zinc providing 12 to 22 mg and iron at .05 mg.

Grapefruit is harvested when fully ripened and is available in the supermarkets year round. However, its peak season is January through June. Grapefruit can keep a week or slightly longer at room temperatures of 65 degrees or higher. For longer storage, about six to eight weeks, store the fruits in the fruit and vegetable keeper of the refrigerator. Commercial grapefruit is often washed and waxed before coming to market to retard moisture loss and lengthen shelf life. Frequently, fumigants and fungicides are applied to the grapefruit to prevent spoilage. Wash grapefruit thoroughly before cutting into the flesh. For a juicy grapefruit, choose one that feels solid and weighty. Look for a shiny, smooth skin to be sure of freshness. Reject those with soft areas, large brown spots, or dull dry looking skin. To consume grapefruit at optimum flavor, keep the fruit at room temperature at least 2 hours before eating. The traditional half grapefruit sectioned with a grapefruit knife simply can't be beat. Enjoy it as a breakfast, lunch, or dinner starter.

If the grapefruit's distinct bitter bite is not to your liking, sweeten with a spoonful agave nectar, maple syrup, date sugar, or Florida crystals and add a dash of cinnamon. Nothing compares to the delightfully rich flavor of a glass of freshly squeezed grapefruit juice. When fresh grapefruit is not available, frozen juice is an excellent substitute. Grapefruit juice adds a robust zing when blended with other fruits such as apples, pears, and oranges. Prepare a refreshing beverage or smoothie in the blender. Grapefruit has a natural affinity for the avocado. Combine them in a salad along with greens and some crunchy vegetables like jicama, celery, sweet onions, or kohlrabi. Add a tangy dressing or one with a hint of fruity sweetness. When citrus is in season, take advantage of the varieties by joining them together in a fruit cup, a beverage, or a salad. Include white, pink, and red grapefruit for more color variety. Grapefruit sections, either pink or white, along with orange and tangerine sections make a tempting salad dish when arranged over spinach or baby greens and topped with sweet onion rings and a creamy avocado dressing.

Elysa Markowitz in her book Living With Green Power creates an innovative zesty soup by juicing 2 oranges and 3/4 of a peeled grapefruit. She then garnishes the soup with 1 sliced avocado, 1 orange, and the remainder of the grapefruit. Make a grapefruit spritzer with sweet grapefruit juice and seltzer. Score the whole grapefruit and peel as you would an orange. Separate the top portion of the sections, keeping the bottoms attached. Open like flower petals and fill center with fruit salad or a tangy chopped vegetable salad. Prepare a unique sorbet with grapefruit juice. Thin slightly with water, sweeten to taste, and freeze about 2 or 3 hours. Remove and stir, and return to the freezer until ready to serve. Grapefruit - Types and varieties Grapefruit Grapefruit, Citrus paradisi / Rutaceae The varieties are divided in two groups: the white ones, within which we find the most well-known variety, �Marsh seedless", and the coloured varieties, such as " Ruby" or " Star Ruby".

We can divide the varieties in two groups, the white or common varieties, such as "Marsh seedless" and "Duncan" and the coloured or pigmented varieties, whose popularity is increasing. Within this group stand out �Ruby", and "Star Ruby". Many white varieties have been identified but " Marsh seedless" is the one with a greater commercial importance. The pigmented varieties have a pigment called licopene that gives them their characteristic colour. They are differentiated from oranges in the fact that their colour is given by the anthocyanins. Moreover, during the period of grapefruit maturation, the temperatures are high and favour the appearance of the licopene. This does not happen in autumn and winter, when oranges ripen. Some grapefruit varieties are: "Marsh seedless" The pulp of this fruit has small vesicles and the pulp has a clear colour appearance. The skin is thicker than the rest of varieties, the juice content is high, sweet, although somehow acid in the beginning of the harvesting. The fruits are seedless and their weight is around 260 g. If they are degreened in chambers, they lose their aroma but still stay acid. "Duncan" Quite big fruit, flattened in the poles.

The pulp is tender and juicy. This variety is mainly intended for the juice industry. "Ruby" Its name is due to the pink colour of its skin and pulp. It is a seedless fruit. It is the reference variety for those consumers who prefer the coloured grapefruits. "Star Ruby" It is the most intense coloured grapefruit. Seedless, with a very thin skin and high juice content, sweeter flavour and less bitter than the Marsh variety. Grapefruit Types: Flame, Marsh, Star Ruby, and More | Berkeley Wellness Print Grapefruit comes in white, pink, and red varieties, colors that refer to the flesh of the fruit. All three types are similar in taste and texture. Most grapefruits sold as table fruits are seedless. The varieties that have seeds are often used for making grapefruit juice. The most common grapefruit on the market is the White Marsh seedless. Here are some types of grapefruit you may find in stores and farmers’ markets: Duncan grapefruit: This large, yellow-skinned Florida grapefruit is very juicy and flavorful. Because it is very seedy it is generally used for juicing.

Flame grapefruit: Dark pink in color, the Flame grapefruit is more richly colored than the classic Ruby Red. Known for its juiciness, the Flame is a particularly sweet variety. Lavender Gem grapefruit: A grapefruit-tangelo hybrid, the Lavender Gem resembles a mini grapefruit with either a lemon-yellow rind or a pink blush. The flesh is pinkish-blue with some small seeds. These grapefruits are delicate in flavor. Marsh Seedless grapefruit: The white Marsh is the most popular variety of grapefruit. With yellow-white flesh and yellow skin, this grapefruit is both sweet and acidic. Other Marsh grapefruits include the pink Marsh, which generally has yellow skin with a pink blush. The pink flesh is slightly less acidic and sweeter than that of the white Marsh. The ruby red Marsh has yellow to pale red skin and red flesh. It is less acidic than the white Marsh and is considerably sweeter. Melogold grapefruit: This cross between a pomelo and a grapefruit was the result of research conducted by two scientists from University of California at Riverside in the late 1950s. Their size varies, but they can be very large.

Melogolds are juicy and taste likes oranges with grapefruit overtones. They have a smooth, easy-to-peel rind and contain practically no seeds. Oro Blanco grapefruit: Another cross between a pomelo and a grapefruit, oro blanco, which means white gold in Spanish, is sweet and juicy without any bitterness or acidity. Oro blancos have yellow skin, a thick rind, and are nearly seedless. Star Ruby grapefruit: Both tart and sweet, the Star Ruby has smooth yellow skin with a pink blush and deep red flesh. As a general rule of thumb, the redder the flesh, the sweeter the fruit. Sweeties: Yet another cross between the grapefruit and a pomelo, these look like green grapefruits and, as their name suggests, they are sweet. Thompson grapefruit: Similar in flavor to the Marsh grapefruit, Thompsons are widely grown in Texas, and gaining popularity because they are mostly seedless. Grapefruit - MyCitrusTree 0 - 6 LARGE Thick, easy-to-peel rind ranging in color from green to yellowish, white flesh. Juicy, sweet-to-sweet tart flavor. Eat like a grapefruit.

Fruit more rounded than Hirado Buntan. Note: Nothing requires a pollinator; if did, may produce more fruit. < 25-30 F, need to protect all citrus. HARD FREEZE: 28 F > 4 hrs. These evergreen trees are usually found at around 5–6 metres (16–20 ft) tall, although they can reach 13–15 metres (43–49 ft). The leaves are dark green, long (up to 150 mm, or 6 inches) and thin. It produces 5 cm (2 in) white four-petaled flowers . The fruit is yellow-orange skinned and largely an oblate spheroid ; it ranges in diameter from 10–15 cm. The flesh is segmented and acidic , varying in color depending on the cultivars , which include white, pink and red pulps of varying sweetness. The 1929 US Ruby Red (of the Redblush variety) has the first grapefruit patent.[3] The fruit has become popular since the late 19th century; before that it was only grown as an ornamental plant.

The United States quickly became a major producer of the fruit, with orchards in Florida , Texas , Arizona , and California . In Spanish, the fruit is known as toronja or pomelo. Source: Other Citrus Varieties Grapefruit Morton, J. 1987. Grapefruit. p. 152158. In: Fruits of warm climates. Julia F. Morton, Miami, FL. Grapefruit Other Uses A relative newcomer to the citrus clan, the grapefruit was originally believed to be a spontaneous sport of the pummelo (q.v.). James MacFayden, in his Flora of Jamaica, in 1837, separated the grapefruit from the pummelo, giving it the botanical name, Citrus paradisi Macf. About 1948, citrus specialists began to suggest that the grapefruit was not a sport of the pummelo but an accidental hybrid between the pummelo and the orange. The botanical name has been altered to reflect this view, and it is now generally accepted as Citrus X paradisi.

When this new fruit was adopted into cultivation and the name grapefruit came into general circulation, American horticulturists viewed that title as so inappropriate that they endeavored to have it dropped in favor of "pomelo". However, it was difficult to avoid confusion with the pummelo, and the name grapefruit prevailed, and is in international use except in Spanish-speaking areas where the fruit is called toronja. In 1962, Florida Citrus Mutual proposed changing the name to something more appealing to consumers in order to stimulate greater sales. There were so many protests from the public against a name change that the idea was abandoned. Plate XVIII: NAVEL GRAPEFRUIT, Citrus × paradisi Description The grapefruit tree reaches 15 to 20 ft (4.5-6 m) or even 45 ft (13.7 m) with age, has a rounded top of spreading branches; the trunk may exceed 6 in (15 cm) in diameter; that of a very old tree actually attained nearly 8 ft (2.4 m) in circumference. The twigs normally bear short, supple thorns.

The evergreen leaves are ovate, 3 to 6 in (7.5-15 cm) long, and 1 3/4 to 3 in (4.5-7.5 cm) wide; dark-green above, lighter beneath, with minute, rounded teeth on the margins, and dotted with tiny oil glands; the petiole has broad, oblanceolate or obovate wings. The white, 4-petalled flowers, are 1 3/4 to 2 in (4.5-5 cm) across and borne singly or in clusters in the leaf axils. The fruit is nearly round or oblate to slightly pear-shaped, 4 to 6 in (10-15 cm) wide with smooth, finely dotted peel, up to 3/8 in (1 cm) thick, pale-lemon, sometimes blushed with pink, and aromatic outwardly; white, spongy and bitter inside. The center may be solid or semi-hollow.

The pale-yellow, nearly whitish, or pink, or even deep-red pulp is in 11 to 14 segments with thin, membranous, somewhat bitter walls; very juicy, acid to sweet-acid in flavor when fully ripe. While some fruits are seedless or nearly so, there may be up to 90 white, elliptical, pointed seeds about 1/2 in (1.25 cm) in length. Unlike those of the pummelo, grapefruit seeds are usually polyembryonic. The number of fruits in a cluster varies greatly; a dozen is unusual but there have been as many as 20. Origin and Distribution The grapefruit was first described in 1750 by Griffith Hughes who called it the "forbidden fruit" of Barbados. In 1789, Patrick Browne reported it as growing in most parts of Jamaica and he referred to it as "forbidden fruit" or "smaller shaddock".

In 1814, John Lunan, in Hortus Jamaicensis, mentions the "grapefruit" as a variety of the shaddock, but not as large; and, again, as "forbidden fruit", "a variety of the shaddock, but the fruit is much smaller, having a thin, tough, smooth, pale yellow rind". In 1824, DeTussac mentions the "forbidden fruit or smaller shaddock" of Jamaica as a variety of shaddock the size of an orange and borne in bunches. William C. Cooper, a citrus scientist (USDA, ARS, Orlando, Florida, to 1975), traveled widely observing all kinds of citrus fruits. In his book, In Search of the Golden Apple, he tells of the sweet orange and the grapefruit growing wild on several West Indian islands. He cites especially a fruit similar to grapefruit that is called chadique growing wild on the mountains of Haiti and marketed in Port-au-Prince. The leaves are like those of the grapefruit.

He says that it was from the nearby Bahama Islands in 1823 that Count Odette Phillipe took grapefruit seeds to Safety Harbor near Tampa, Florida. When the seedlings fruited, their seeds were distributed around the neighborhood. At first, the tree was grown only as a novelty in Florida and the fruit was little utilized. Even in Jamaica, the trees were often cut down. Mrs. Mary McDonald Carter of Eustis, Florida, was quoted in the Farm and Livestock Record, Jacksonville, in 1953, as relating that her father, John A. MacDonald, settled in Orange County in 1866. In 1870, he was attracted to a single grapefruit tree with clusters of lemon-colored fruits on the Drawdy property at Blackwater. He bought the entire crop of fruits, planted the seeds and established the first grapefruit nursery. The first grapefruit grove planted from this nursery by a man named Hill was sold in 1875 to George W. Bowen who developed it commercially. In 1881, MacDonald bought the Drawdy crop and once more raised seedlings for his nursery in Eustis.

Early settlers began planting the tree and acquired a taste for the fruit. There was already a small demand in the North. New York imported 78,000 fruits from the West Indies in 1874. Florida started sending small shipments to markets in New York and Philadelphia between 1880 and 1885. In 1898, Dr. David Fairchild was excited to learn of a grove of 2,000 grapefruit trees in the Kendall area south of Miami on the property of the Florida East Coast Railway. In 1904, he was amazed to see one tree in the door-yard of the Kennedy ranch in southern Texas where he thought the climate too cold for it. He was told that the tree had been frozen to the ground but had recovered. He predicted that a citrus industry could not be established in that region of the country. In 1928, he photographed the same tree, which had been killed back several times in the interim, but was again in fruit. By 1910, grapefruit had become an important commercial crop in the Rio Grande Valley and, to a lesser extent, in Arizona and desert valleys of California.

By 1940, the United States was exporting close to 11,000,000 cases of grape-fruit juice and nearly one-half million cases of canned sections. Cultivation had reached commercial proportions in Jamaica and Trinidad and spread to Brazil, South America and Israel. In 1945/46, the United States (mainly Florida) produced a record of 2,285,000 tons of grapefruit. In 1967/68, this country accounted for 70% of the world crop despite a great decline in Texas production because of severe weather. Grapefruit was moving forward by leaps and bounds. Israel, in 1967, supplied only 11% of the world crop but, by 1970, her production had increased by 300%. In 1980, Florida exported just under 10 million boxes, making grapefruit this state's most valuable export crop. Japan is the main importer and has, at times, suspended shipments to determine the safety of fungicide residues or because of discovery of larvae of the Caribbean fruit fly. Great care is taken to maintain this important trade.

Other countries which had entered the grapefruit industry were Mexico, Argentina, Cyprus, Morocco and some areas of South America which raise grapefruit for local markets. In Central America, the grapefruit is not much favored because of its acidity. In the late 1960's and early 1970's, Mexico was rapidly expanding its grapefruit plantings, especially in the states of Tamaulipas and Veracruz, to save its citrus industry in view of the decline in market value of oranges and tangerines brought on by over-production. Furthermore, there were great advantages in the lower costs of producing grapefruit without irrigation and with good biological control of pests. Now Mexico exports large quantities of grapefruit to the United States and lesser amounts to Canada and Japan. Puerto Rico formerly exported grapefruit to the United States but is no longer able to compete in the trade and has only remnants of former plantations. Cuba has planted 370,000 acres (150,000 ha) of citrus, mostly grapefruit with expectations of exporting to the Soviet Union and eastern European countries. The grapefruit is grown only in a small way in the Orient where the pummelo is cultivated.

In recent years, the grapefruit has become established in India in hot regions where the sweet orange and the mandarin are prone to sunburn. Varieties Named varieties of grapefruit appeared in the official list of the American Pomological Society in 1897, but pioneers had selected and named favorite clones for several years before that time. The following are among the most noteworthy of old and new cultivars: 'Duncan'the original trees were virtually identical seedlings that grew in a grove owned by a man named Snedicor near Safety Harbor, Florida. Propagation was first undertaken by A. L. Duncan of Dunedin in 1892. The fruit is round or slightly obovate; large, 3 1/2 to 5 in (9-12.5 cm) wide; peel is very light yellow (usually called "white"), with large oil glands, medium-thick, highly aromatic; pulp is buff, in 12-14 segments with medium-tender membranous walls, very juicy, of fine flavor; seeds medium-large, 30-50. Early to mid-season. Tree is unusually cold-hardy.

This was the leading cultivar for many years in Florida and Texas and was introduced into all the grapefruit-growing areas of the world. Today, in the United States, it has largely given way to cultivars with fewer seeds, but it is being grown commercially in India. Recent seed irradiation experiments have shown that a high percentage of seedless mutants results from exposure to 20-25 krad. 'Foster' ('Foster Pink Flesh')Originated as a branch sport of a selection called 'Walters' in the Atwood Grove near Ellenton, Florida, discovered by M.B. Foster of Manatee in 1906, and propagated for sale by the Royal Palm Nurseries. Fruit is oblate to round; medium-large, averaging 3 3/4 in (9.5 cm) in width; peel light-yellow blushed with pink, smooth but with large, conspicuous oil glands; albedo pink; pulp light-buff, pinkish near the center; in 13 or 14 segments with pinkish walls, tender, juicy, of good quality despite seeds, up to 50 or even more, of medium size. Medium-early in season.

Not very popular; grown to a limited extent in Florida, Texas, Arizona and India. In Texas, it is more colorful, the pulp being entirely pinkish in hue. 'Marsh' ('Marsh Seedless')one of 3 seedling trees on the property of a Mrs. Rushing near Lakeland, Florida, purchased by William Hancock in 1862. Because the fruits of this tree were seedless, C.M. Marsh took budwood from it for nursery propagation and he bought young trees previously budded by others. He sold the budded offspring and, in time, the 'Marsh' was planted more than any other cultivar. The original tree was killed by cold in the winter of 1895-96. The fruit is oblate to round, medium in size, 3 1/2 to 4 3/4 in (9-12 cm) wide; peel is light-yellow, very smooth, with medium-size oil glands, mildly aromatic; pulp is buff, in 12-14 segments with tender membranes, melting, extremely juicy and rich in flavor; seeds absent or 3-8, medium-sized. Medium to late in season and holds well on the tree.

Keeps well after harvest. The leading grapefruit cultivar; grown in Florida, California, Texas, Arizona, South America, Australia, South Africa, Israel and India. A local selection, presumably of a seedling 'Marsh', in Surinam is known there as 'Hooghart'. The two are almost indistinguishable. 'Oroblanco'a triploid from a grapefruit X pummelo cross made in 1958 by geneticists R.K. Soost and J.W. Cameron of the University of California, Riverside. Patent obtained in 1981 and assigned to the University of California Board of Regents. Fruit form and size similar to 'Marsh'; peel paler and thicker; pulp paler and has larger hollow in center; sections easily skinned; tender, juicy, non-bitter; has faintly astringent after-taste before full maturity or in cooler climates; seedless. Season early: December to April at Riverside; early November through February at Landcove. Tree is vigorous, large, hardy, can tolerate temperatures down to 30º F (-1.11º C); yields medium to heavy crops and may tend to alternate bearing.

Seems better adapted to California's inland citrus locations than to desert sites. Has been grown experimentally on trifoliate orange, 'Troyer' citrange, citremon 1449, Brazilian sour orange, grapefruit, sweet orange, rough lemon and 'Red' rough lemon rootstocks. The two latter have adversely affected internal quality 'Paradise Navel'a selection from the 100-year-old Nicholson citrus grove near Winter Garden, Florida; propagated and patented by W.H. Nicholson, improved and released for distribution in 1976. Fruit is oblate, smaller than a typical grapefruit. Originally very seedy, but, by budding onto various rootstocks and transferring from one rootstock to another over a period of years, there eventually emerged one tree bearing fruit without seeds. Budwood from this tree has produced uniformity of seedlessness regardless of rootstock. The fruits have been sold to local customers but no scions nor trees were sold prior to 1976.

'Redblush' (including 'Ruby', 'Ruby Red', 'Shary Red', 'Curry Red', 'Fawcett Red', 'Red Radiance', and 'Webb' [Webb's Redblush Seedless'])originated as sportslower branchesgrowing out of 'Thompson' trees which a Texas nursery had purchased from Glen St. Mary Nursery and sold to growers in the Rio Grande Valley, and which were frozen back in 1929. All are seedless and otherwise similar to 'Thompson' but display redder color. 'Redblush' grapefruits have been extensively planted in Florida in the past few decades though the juice is not suitable for canning as it tends to turn brown with age. By 1950, 75% of Florida's grapefruit crop was of the pink or red seedless type. Under the name, 'Ruby Red', a member of this group is a standard commercial cultivar in Texas.

In 1958, budwood of 'Redblush' from California was acquired by the Regional Fruit Research Station at Abohar, India, was propagated on rough lemon, and the resulting trees performed so well and showed such disease resistance that the cultivar was recommended for growing under irrigation in the and regions of the Punjab and Haryana, where it averages 250 fruits annually per tree. Probably includable in this group is 'Burgundy'. Its peel is not blushed but the pulp is intense red throughout the season. 'Ray Ruby' and the similar if not identical 'Henderson' are branch sports propagated in Texas and introduced into Florida in the 1970's. The peel is redder than that of 'Ruby Red' and the pulp is red though not as intense as 'Star Ruby' throughout the season. Recently, budwood of 'Ray Ruby' has become available from the Florida Department of Agriculture's Bureau of Citrus Budwood Registration in Winter Haven. 'Ray Ruby' is expected to perform better than 'Star Ruby' on standard rootstocks.

'Star Ruby'a lower branch mutation bearing red-blushed fruits, noticed on a 'Foster' tree at San Benito, Texas, in the mid 1930's. The tree had been frozen back nearly to the bud union the previous year. Budwood from the branch was propagated by C. E. Hudson as the 'Hudson Red' but, because of its coarse texture and high number of seeds (40-60), it was not adopted commercially. Seeds were irradiated at the Texas A & I Citrus Center, Weslaco, in 1959. The seedling from one of these treated seeds was named the 'Star Ruby' and introduced into cultivation in 1971 by Richard Hensz of Texas A & I University. Several thousand trees were planted in Texas. At least 65,000 budded trees were brought into Florida in 1971 by commercial interests without proper qualifications and permits under the Division of Plant Industry. Investigation revealed a susceptibility to Phytophthora root rot and ringspot virus in Texas. The Florida State Agricultural Commissioner ordered the destruction of all unauthorized imported trees.

About 25,000 were voluntarily destroyed by owners but the ruling was contested and the trees were placed under quarantine. Subsequently, ringspot virus was found on one of the imported trees which had already been used as a source of budwood. Infected trees from this source were found in a nursery and were destroyed together with all neighboring healthy trees. By April 1977, certified, disease-free budwood of 'Star Ruby' was made available and nearly 200,000 "budeyes" were released to growers. They were urged to make only limited plantings until more was known of this cultivar's fruiting habits. The tree tends to become more chlorotic than 'Ruby Red' when sunburned or affected by poor drainage, or high applications of herbicides and pesticides, and it is sensitive to adverse weather conditions. 'Star Ruby' has a yellow peel distinctly red-blushed and in tensely red pulp and juice, 3 times more colorful than 'Ruby Red'. Though the color decreases with maturity, it is maintained throughout the season. The pulp is smooth and firmer than that of 'Ruby Red' and has a bit more sugar and acid.

Furthermore, there may be no seeds or no more than nine. Some of the juice color is dissipated by heat in the pasteurization process but there is still enough for the product to be blended with white or pink grapefruit juice to provide more consumer appeal. 'Sweetie'a grapefruit × pummelo hybrid released in 1984 by the Citrus Marketing Board in Israel, has all the features of a typical grapefruit but the flavor is sweet. 'Thompson' (Pink Marsh')In 1913, one branch of a 'Marsh' tree owned by W. R. Thompson, Oneco, Florida, bore pink-fleshed, seedless fruits. Propagation of budwood from the branch was undertaken by the Royal Palm Nurseries in 1924. A similar bud variation of the 'Marsh' had appeared around 1920 at Riverside, California.

The fruit is oblate to round, of medium size, 2 3/4 to 3 3/4 in (7-9.5 cm) wide; peel is light-yellow, smooth, with small, inconspicuous oil glands, faintly aromatic; pulp is light- to deep-buff more or less flushed with pink, sometimes throughout, occasionally just near the center. There are 12 to 14 segments with abundant, colorless juice, and few seedsusually 3 to 5. The color of the pulp is most intense in January and February. By late March and April it has faded to nearly amber. 'Triumph' (possibly the same as 'Royal' and 'Isle of Pines')a seedling on the grounds of the Orange Grove Hotel in Tampa, Florida, propagated in 1884.

The fruit is oblate to ellipsoid, slightly flattened at both ends; of medium size; peel light-yellow, very smooth, with oil glands of medium size; medium-thick; pulp pale, tender, juicy, only faintly bitter, the flavor having a touch of orange; the center is semi-hollow; of superior quality; 35-50 seeds. Medium-early in season, beginning in November. Grown only in dooryards in Florida, but has been widely distributed in citrus regions; does better than 'Marsh' in South Africa. A grapefruit-like, triploid hybrid named 'Melogold' was developed by crossing a sweet pummelo with a seedy, white, tetraploid grapefruit in 1958. The fruit is larger than 'Marsh' grapefruit and its pummelo-like flavor is considered superior though it may have a trace of bitterness at the beginning and end of the season which extends from early November or December through February. 'Melogold' is grafted onto rough lemon and 'Troyer' citrange rootstocks and is recommended for interior California, not in hot desert nor in humid coastal situations.

Patent rights are held by the University of California and budwood is released only to licensed nurserymen. Climate The grapefruit prospers in a warm subtropical climate. Temperature differences affect the length of time from flowering to fruit maturity. At Riverside, California the period is 13 months; at warmer Brawley in the Imperial Valley of southern California, only 7 to 8 months. The fruit is lower in acidity in the Indian River region and areas of southern Florida, the lower Rio Grande Valley of Texas, and in the tropics than in cooler situations. Humidity contributes to thinness of peel, while in arid climates the peel is thicker and rougher and, as might be expected, the juice content is lower. Low winter temperatures also result in thicker peel the following year and even affect the fruit shape. Ideal rainfall for grapefruit is 36 to 44 in (91.4-111.7 cm) rather evenly distributed the year around. Soil The grapefruit is grown on a range of soil types. In the main growing area of Florida, the soil is mildly acid sand and applications of lime may be beneficial.

On the east coast there are coquina shell deposits and, in the extreme southern part of the peninsula, there is little soil mixed with the prevailing oolitic limestone. Where the grapefruit is grown in California, Arizona and Texas, the soils are largely alkaline and frequent irrigation causes undesirable alkaline salts to rise to the surface. In Surinam, grapefruit is grown on clay. Successful grapefruit culture depends mainly on the choice of rootstock best adapted to each type of soil. Salinity of the soil and in irrigation water retards water uptake by the root system and reduces yields. Propagation In the early years of grapefruit-growing, the customary citrus rootstocks were utilized: sour orange on heavy hammock and flatwoods soils, rough lemon on sand, though trees grafted on this stock were short-lived. In the early 1950's, sweet orange was being preferred over sour orange. In 1946, the United States Department of Agriculture, Texas A & M University, and Rio Farms, Inc., of Monte Alto, Texas, launched a cooperative program of testing grapefruit on different rootstocks.

Of 13 different rootstocks utilized, 'Swingle citrumelo', 'Morton' and 'Troyer' citranges gave the best yield of large fruits. Rough lemon and 'Christian' trifoliate orange reduced acidity. 'Swingle citrumelo' was never used extensively as a rootstock until 1974 when it was released to nurserymen and growers because of its tolerance of exocortis, xyloporosis, and tristeza and resistance to foot-rot and citrus nematode, and low uptake of salts, together with its ability to support heavy crops. It is now in third place after 'Troyer' citrange and sour orange. In the past, 'Marsh' and 'Hooghart', the commercial grapefruits of Surinam, have been grown there on sour orange rootstock, but fear of tristeza inspired a rootstock testing program. Among the stocks tried, 'King' and 'Sunki' resulted in high yield and excellent quality in contrast to rough lemon and Rangpur lime. The two latter also showed susceptibility to Phytophthora root rot.

'Cleopatra' lowered the yield, and trifoliate orange proved unsatisfactory in such a humid climate. In the Lower Rio Grande Valley of Texas, grapefruit trees on 'Swingle citrumelo' have grown very poorly on heavy clay as compared to those on sour orange. Culture In general, culture of grapefruit is similar to that of the orange, q.v., except that wider spacing is necessary. Nutritional experiments with grapefruit have shown that excessive nitrogen results in malformed fruit, coarser texture and less juice. Lack of certain minor elements is evident in symptoms often mistaken for disease. The condition called exanthema is caused by copper deficiency; mottle leaf results from zinc deficiency. Harvesting and Handling In Florida, all commercial cultivars reach legal maturity in September or October if sprayed after blooming with lead arsenate to reduce acidity. Even after legal maturity the grapefruit can be "stored" on the tree for months, merely increasing in size, and extending the marketing season. The fruits can be harvested until near the end of May when they begin to fall and seeds start sprouting in the fruit. The only adverse effect of late harvesting is a corresponding reduction in the following year's crop.

It has been found that spot-picking of the largest fruits partially counteracts this effect of late harvest. Fruit drop can be retarded by spraying with a combination of gibberellic acid and 2,4-D. Either of these agents or both together will reduce the germination of seeds. Germination may be inhibited for periods up to 11 weeks by cool storage at 50º F (10º C). Grapefruits were formerly harvested by climbing the trees or using picking hooks which frequently damaged the fruit. Today, the fruits on low branches are picked by hand from the ground; higher fruits are usually harvested by workers on ladders who snap the stems or clip the fruits as required. California began utilizing a modified olive limb-shaker for harvesting grapefruit in 1972. The machines work in pairs to harvest opposite sides of each tree and the trees must be pruned to remove deadwood and to give access to 3-5 main limbs for shaking. Lower branches must be lopped off to leave a clear 2 1/2 ft (75 cm) space for the catching frame. Mechanical harvesting causes some superficial injury.

A team of 3 workers with one machine can harvest 150 to 188 field boxes50 lbs (22.7 kg) when filledper hour, as compared with 45 boxes per hour for 3 manual pickers. Stems are removed from the fruits before packing to avoid stem-damage. Early in the season, when the fruits are mature but not fully colored, they are often degreened by exposure to ethylene gas. The grapefruit is remarkable for its durability, but modern practices of applying fungicide to the harvested fruit are given credit for the great reduction in marketing losses. The cull rate in New York wholesale warehouses in 1983 was found to be 1.4% (mostly fungal), as compared with 13 % estimated in 1960. Retail losses in 1983 were 3.5%, and only a small proportion were the result of physical injury. Keeping Quality The grapefruit keeps well at 65º F (18.33º C) or higher for a week or more and for 2 or 3 weeks in the fruit/vegetable compartment of the home refrigerator.

The first sign of breakdown is dehydration and collapse of the stem-end. To retard moisture loss, fruits for marketing are washed and waxed as soon as possible after harvest. When kept in prolonged storage, the grapefruit is subject to chilling injury (peel pitting) at temperatures below 50º F (10º C). The degree of injury depends on several factors: the fruits on the outside of the tree are more susceptible than the fruits that have been sheltered by foliage. The use of preharvest growth regulators tends to reduce susceptibility, as does 100% relative humidity during storage. Preconditioning at 60.8º F (16º C) for 7 days before storing at 33.8º F (1º C) prevents injury. Lowering the temperature gradually after preconditioning is also beneficial, as is sealing the fruit in polyethylene shrink-film before refrigerating. The banning of ethylene dibromide fumigation except for export has made it necessary to resort to cold treatment as an alternative measure against fruit fly infestation for shipment to Texas, Arizona and California.

The United States Department of Agriculture now requires that imported citrus fruits be kept at 32º F (0º C) for 10 days or at 36º F (2.2º C) for 16 days after the fruit has been cooled down to the specified temperature. In Israel, investigators have found that waxing with a coating containing fungicide, and holding the packed fruit for 6 days at 62.6º F (17º C) before the cold treatment, gives good protection from chilling injury and decay in storage. Cold treatment costs 5 times as much as fumigation with ethylene dibromide. Methyl bromide has been tested and proposed as an effective fumigant, Pests and Diseases The grapefruit is subject to most of the same pests that attack the orange, including Caribbean and Mediterranean fruit flies. In addition to the cold treatment referred to above, irradiation has been studied as a method of disinfection, but has not been authorized for citrus fruit treatment. Exposure of early-season fruit to 60 and 90 krad causes scald and rind breakdown after 28 days of storage, and mainly pitting in midseason and late fruits.

Minimal injury results from exposure to 7.5, 15, and 30 krad. The following diseases have been reported for the grapefruit tree and its fruit by the Florida Division of Plant Industry: leaf spot (A1ternaria citri, Mycosphaerella horii, Phyllosticta hesperidearum); algal leaf spot (Cephaleuros virescens); greasy spot (Cercospora citri-grisea); tar spot (C. gigantea); anthracnose (Colletotrichum gloeosporioides); thread blight (Corticium koleroga and C.

stevensii); gummosis (Diaporthe citri); dieback (Diplodia natalensis); heart rot (Fomes applanatus, Ganoderma sessilis, and Xylaria polymorpha); charcoal root rot (Macrophomina phaseolina); root rot (Fusarium oxysporum); sooty blotch (Gloeodes pomigena); flyspeck (Leptothyrium pomi); mushroom root rot (Clitocybe tabescens); foot rot (Phytophthora megasperma, P. palmivora, and P. parasitica); damping-off (Rhizoctonia solani); seedling blight (Sclerotium rolfsii); felt fungus, (Septobasidium pseudopedi- cellatum); branch knot (Sphaeropsis tumefaciens); leaves may be attacked by Chaetothyricum hawaiiense, and twigs by Physalospora fusca. Brown rot of fruit is caused by Phytophthora citrophthora and P.

terrestris; stem-end rot, Botryosphaeria ribis; dry rot of fruit (Nematospora coryli); green mold (Penicillium digitatum); blue mold, (P. italicum); pink mold (P. roseum); scab (Elsinoe fawcetti). The tree is highly susceptible to citrus canker and several viruses: crinkly leaf virus, psorosis, tristeza, xyloporosis, and infectious variegation. Mesophyll collapse is caused by extreme drought and dehydrating wind. Fig. 39: Grapefruit (Citrus paradisi): pink (left); yellow (center); and russet (right). In: K. & J. Morton, Fifty Tropical Fruits of Nassau, 1946. Food Uses As a relatively new food, the grapefruit has made great advances in the past 75 years. In 1970, consumption of grapefruit was temporarily heightened by a widely promoted "grapefruit diet" plan claimed to achieve a loss of 10 lbs (4.5 kg) in 10 days and continuous gradual loss until the achievement of normal body weight.

In 1983, the United States Department of Agriculture Marketing Service reported that, among fresh fruits and vegetables consumed in Metropolitan New York, grapefruit was exceeded only by potatoes, lettuce, oranges and apples. Grapefruit is customarily a breakfast fruit, chilled, cut in half, the sections loosened from the peel and each other by a special curved knife, and the pulp spooned from the "half-shell". Some consumers sweeten it with white or brown sugar, or a bit of honey. Some add cinnamon, nutmeg or cloves. As an appetizer before dinner, grapefruit halves may be similarly sweetened, lightly broiled, and served hot, often topped with a maraschino cherry. The sections are commonly used in fruit cups or fruit salads, in gelatins or puddings and tarts. They are commercially canned in sirup. In Australia, grapefruit is commercially processed as marmalade. It may also be made into jelly. The juice is marketed as a beverage fresh, canned, or dehydrated as powder, or concentrated and frozen. It can be made into an excellent vinegar or carefully fermented as wine.

Grapefruit peel is candied and is an important source of pectin for the preservation of other fruits. The peel oil, expressed or distilled, is commonly employed in soft-drink flavoring, after the removal of 50% of the monoterpenes. The main ingredient in the outer peel oil is nookatone. Extracted nookatone, added to grapefruit juice powder, enhances the flavor of the reconstituted juice. Naringin, extracted from the inner peel (albedo), is used as a bitter in "tonic" beverages, bitter chocolate, ice cream and ices. It is chemically converted into a sweetener about 1,500 times sweeter than sugar. After the extraction of naringin, the albedo can be reprocessed to recover pectin. Grapefruit seed oil is dark and exceedingly bitter but, bleached and refined, it is pale-yellow, bland, much like olive oil in flavor, and can be used similarly. Because it is an unsaturated fat, its production has greatly increased since 1960.

Food Value Per 100 g of Edible Portion* Pulp (raw) 12-14 mg *According to analyses made in California, Texas, Florida, Cuba and Central America. **Peel Oil: 90% limonene; the volatile fraction (2-3%) consists mainly of oxygen compounds and sesquiterpenes; the waxy fraction (7-8%) consists of C8 and C10 aldehydes, plus geraniol, cadinene and small amounts of citral and dimethyl arthranilate, plus acid. Also present are 9 coumarins and 0.88% 22-dihydrostigmasterol. The dried pulp and seeds contain b-sitosteryl-D-glucoside and b-sitosterol. The glycoside 7 b-neohesperidosyl-4-(b-D-glucopyranosyl) naringenin occurs in the pulp segments. Feruloylputrescine is found in the juice and leaves. Mature grapefruit leaves contain the flavonoid, apigenin 7 b-rutinoside.

Young leaves contain the 7 b-neohesperidoside and 7 b-rutinoside of naringenin. Other Uses Factory waste: The waste from grapefruit packing plants has long been converted into molasses for cattle. Seed hulls: After oil extraction, the hulls can be used for soil conditioning, or, combined with the dried pulp, as cattlefeed. A detoxification process must precede the feeding of this product to pigs or poultry. Wood: Old grapefruit trees can be salvaged for their wood. The sapwood is pale-yellow or nearly white, the heartwood yellow to brownish, hard, fine-grained, and useful for domestic purposes. Mainly, pruned branches and felled trees are cut up for firewood. Medicinal Uses: An essence prepared from the flowers is taken to overcome insomnia, also as a stomachic, and cardiac tonic. The pulp is considered an effective aid in the treatment of urinary disorders. Leaf extractions have shown antibiotic activity.

Question: What fruit has varieties called 'Duncan' and 'Marsh'?
Answer: GRAPEFRUIT