Table of Contents
- 1 Etymology
- 2 Grapefruit varieties
- 3 Planting grapefruit
- 4 Growing grapefruit
- 5 Pests
- 6 Grapefruit uses
- 7 History and facts
Grapefruit (lat. Citrus x paradisi) is a species from the genus Citrus same as lemon, orange, tangerine, mandarin orange and pummelo. The plant belongs to the family Rutaceae, clade Aurantioideae. The origin of grapefruit has not been sufficiently researched, and it is presumed that the plant originates from the island of Barbados. Today, it mostly can be found in the Central American archipelago, and it is also widespread in Florida, as well as Mediterranean regions along with pummelo.
Its value began to stand out from 1885, when it became highly popular on the American market, and later its importance came to the fore in the Mediterranean, although at that time this type of citrus fruit was still neglected in some way.
Grapefruit is a very tall tree. In favorable climatic conditions, it can reach between 10 - 15 m (30 - 50 ft). It has a round or a broadly conical crown. According to the development of the canopy, it is one of the largest types of citrus fruits.
The leaves are ovate, dark green and leathery. The petiole is broadly winged, and the flowers are solitary, more often in clusters of 2 - 20 and pleasantly fragrant. The calyx is wide and the anthers have large pollen. The ovary has 11 to 14 septa. The fruit is large, round or pear-shaped, with a thin pale yellow rind. Its flesh is soft, with a lot of fragrant juice and a pleasant bitter-sour-sweet taste. The fruit usually contains few polyembryonic seeds.
It is widely assumed that the marketing term "grapefruit" (grape + fruit) is an allusion to grapelike clusters growing on a fruit tree. In early 19th century, Ciardi proposed another interesting theory that since pummelo’s botanical name is Citrus grandis (translated "great citrus [fruit]), a new hybrid might first have been called "greatfruit" resulting the word to be pronounced "grapefruit" through the process of dissimilation.
Grapefruit itself was known since 1693 and it was first written in Hans Sloane's catalogue of Jamaican plants. It presumably originates from Jamaica as a hybrid between other cultivated citrus species. It was first an ornamental plant, and not much eaten until late 19th century.
As the range of this citrus variety is expanding, the selection of varieties has grown to a considerable number. The most famous species are red, white and pink grapefruit.
An unwritten rule says that the redder the fruit, the sweeter it is. However, this does not apply to red grapefruit. This grapefruit has a very bitter taste. The fruit gets its lovely red color from lycopene and contains beta-carotene, another useful antioxidant.
White grapefruit has a creamy yellow rind and is not as sweet as other species. He’s the least sweet of them all, but that doesn’t mean it tastes bad. When you slice it, the first thing you will notice is its intense aromatic scent that will fill the entire room. It’s usually used in juices, fruit drinks, and even syrups. The juice of a white grapefruit is clear and colorless.
Most people who have tried this type of grapefruit say it is one of the tastiest types of grapefruit they have ever tasted. It can be eaten fresh or made into juice. In terms of sweetness, color and tenderness, it can be placed between red and white grapefruit.
When you cut a flame grapefruit variety, you will find dark pink flesh. Flame grapefruit has a very juicy and sweet taste and contains little or no seeds. The time of ripening is from November to May. Because the fruits can stay on the trees for a long time, they can easily be stored and preserved for several months, which is the reason why is available at supermarkets even when not in season.
Lavender gem grapefruit is a combination of grapefruit and tangle, and it looks like a miniature grapefruit. It also has very few seeds, and its flesh is pinkish-blue with a not very intense taste. On the outside, it can be recognized by its lemon-yellow or pink skin. Although it has only a few seeds, it is full of juice. Lavender gem grapefruit variety is used in juices, other drinks and fruit salads.
The Duncan variety is one of the most famous, oldest and sweetest grapefruit varieties. The fruit is large and yellow, full of flavor so that every bite is cracked with juice. It is mostly used to make fresh juice because it contains a lot of seeds.
Marsh grapefruit variety is one of the most popular varieties because it is the most available on the market. It looks like a large lemon on the outside and is yellow on the inside. It has a sweet-sour taste and is also called white grapefruit. There are very few seeds or none at all.
Oro Blanco grapefruit is a hybrid created by crossing pummelo and grapefruit. Oro Blanco in Spanish means "white gold". Its bark is also yellow, and the inside is almost seedless, juicy and sweet. The taste is not at all bitter or sour.
Melogold grapefruit is a hybrid between pummelo and grapefruit and it originates from California. California farmers cultivated this fruit in the late 50s and since then it has become a popular choice among those who have cravings for an extremely juicy orange-like fruit with a mixed grapefruit flavor. This variety doesn’t have a lot of seeds.
Choosing a place to plant grapefruit is very important, especially if grapefruit is grown for commercial purposes. Grapefruit can be cultivated outdoors, even in warmer habitats, but it is important to raise cypress windshields next to the plantations or to install special prefabricated screens made of polyethylene or sedge husks to protect the plant.
It is first necessary to level the depressions on the land and to fertilize it based on soil analysis. Planting pits need to be driven out beforehand. The depth of tillage should be 0.6 m. All the preparation should be done in dry weather and it is needed to loosen the soil at least a month before planting.
Before planting seedlings, the damaged parts of the roots should be cut off and the health of the seedling should be checked. The seedling should be planted so deep that the grafted site is approximately 10 cm from the ground (aided by a stake). The root of the seedling itself needs to be covered by high-quality soil or compost. After you plant the tree, put manure around the seedling (in the shape of a ring).
Growing in pots
If you plan on planting grapefruit in a pot or a container, keep in mind that it requires a lot of light, so it is best to keep it on the lighted, south side. In winter, it is necessary to bring it indoors, preferably on a glazed balcony where the temperature does not fall below 10°C (50°F). If there is a lack of light, the plant can shed its leaves. If that happens, bare branches should be shortened, so that young shoots can grow at the beginning of spring.
Grapefruit has only recently become popular in cultivation, but due to its growing popularity, it is especially cultivated in the southern regions with a slightly warmer or subtropical climate. For successful grapefruit cultivation, the most important thing is a suitable climate, regular fertilization (manure is suitable), pruning and spraying with pesticides as needed.
Yarrow, dill and fennel attract beetles that feed on aphids, so they are excellent companions for planting with grapefruit and other citrus plants. Parsley and common aphids attract tachinid flies and wasps that kill harmful caterpillars. Another good set of neighbors to grapefruit is legumes, such as peas and alfalfa.
Grapefruit requires a deep soil, rich in humus. Alkaline soils are not suitable as they grow best on neutral or slightly acidic soils. In addition, grapefruit seeks a medium permeable soil in which groundwater never stagnates.
Grapefruit thrives in areas where the average annual temperature is at least 14°C (57°F), and the average winter temperature is at least 10°C (50°F), which corresponds to warmer coastal areas. The dry period should last a maximum of 90 days.
The grapefruit should be fertilized once a week from April to August with a special citrus fertilizer. Yellow leaves are a sign of malnutrition of the plant and thus a warning that the plant needs "food", or fertilizer.
During the summer months, grapefruit requires more water, so it needs to be watered more often. In September, when fertilization stops, watering should be less frequent, i.e. more moderate. The soil should be allowed to dry between waterings.
Pruning grapefruit branches are important because they can affect fruit quality and yields. Grapefruit can also be grown in pots as an ornamental plant, so pruning its branches is also important for aesthetic reasons. Pruning forms a spherical crown and thins the tree. The canopy should be thinned every year at the end of winter before the plant begins to vegetate. Branches that are too long and grow inwards need to be cut.
Grapefruit begins to bear fruit in September and can be harvested throughout the winter, until April. Ripe grapefruit is much heavier than unripe, so this is the best way to distinguish if fruits are matured. Another indicator of maturity is its bark. Before picking, the bark must be as thin and elastic as possible. If the peel quickly returns to its initial position after we press it with our finger, it means that the grapefruit is ripe. It is very important to harvest already ripe grapefruit because after picking it will not ripen anymore.
Since grapefruit spoils very quickly at room temperature due to the presence of oxygen, it is best to store it in the refrigerator. At room temperature, grapefruit can be preserved for only a few days. Before consuming grapefruit, it is good to take it out of the refrigerator and let it sit at the room temperature, as it will be much "juicier".
Diseases and pests
Grapefruit is attacked by all parasites and diseases characteristic of citrus fruits, and the most common parasite is the Mediterranean fruit fly, which lays its eggs in the fruit. Other pests that attack grapefruit are mites, aphids, aphids and caterpillars.
Parasites that attack grapefruit are Phytophthora citrophthora, Colletotrichum gloeosporioides, Septoria citri, Sphaerella gibellina, Penicillium digitatum and P. italicum, Alternaria sp. and Cladosporium sp, Botrytis cinerea, Ascochyta sp, Fusarium sp., Armillaria mellea, Rosellinia necatrix or citrus psorosis, Xanthomonas citri or citrus cancer, Rimocortius psorosis and Pseudomonas syringae.
Leaves, fruits and branches can be attacked by mites:
Two-spotted spider mite (Tetranychus urticae)
Citrus red mite (Metatetranychus citri)
Aceria (Eriophyes) sheldoni
Greenhouse trips (Heliothrips haemorrhoidalis)
The Brown Citrus Aphid (Toxoptera aurantii)
Flower buds and flowers are bitten by caterpillars:
The larvae of the fly Ceratitis capitata also can be seen on grapefruit. Use insecticides or adhesive tapes that catch flies before they lay eggs.
Phytophthora citrophthora - causes root neck rot, gummosis. Infections are most common on the root neck and rare on leaves, flowers, and branches.
The parasite Colletotrichum gloeosporioides - causes anthracnose, arson. It attacks leaves, twigs and fruits.
Parasite Septoria citri - causes small spots, and occurs gradually on leaves and fruits.
Sphaerella gibellina - causes gray spots on the leaves.
Penicillium digitatum and P. italicum - are the most common causes of green fruit rot.
Alternaria sp. and Cladosporium sp. - cause brown fruit rot and Botrytis cinerea gray fruit rot.
Ascochyta sp. - causes round black spots on twigs.
Fusarium sp. - is one of the most dangerous parasites in nurseries, because it is there that it causes the death of seeds.
Armillaria mellea and Rosellinia necatrix - cause root vein rot, but rarely occur.
Pseudomonas syringae - is the cause of the bacterial blight on leaves, branches and fruits.
Xanthomonas citri or citrus cancer - causes freckles on leaves, branches and fruits.
Rimocortius psorosis (citrus psorosis) - causes peeling of the bark, dents and cracks on the tree, as well as whitish-yellow spots and curly leaves.
To prevent your plant to be attacked by pests and parasites, spray it preventively with insecticides.
Although grapefruit is a relatively "new" citrus, its use is diverse. Grapefruit can be consumed fresh or as juice, syrup and jam. Due to its specific and strong scent, essential oils from flowers (nerol), grapefruit leaves and bark are used in the liqueurs and cosmetic industry.
Use in cooking
Grapefruit is best used as fresh food, because when heated, it loses most of its nutrients and all its positive health effects cease to be valid. Grapefruit is primarily used to make fresh juices, but it can also be used for many other culinary purposes. Its refreshing taste goes great with fish, chicken and pork.
Spices that go well with grapefruit are nutmeg, clove and cinnamon, while salt enhances its sweetness. Fresh ginger and herbs like mint, basil and rosemary also combine well with grapefruit, and its blend with chili peppers is also surprisingly pleasant.
Grapefruit can be used to prepare various compotes, salads and sauces. Grapefruit peel is very bitter and is used to flavor tonic water or tea. The crust should be simply boiled, drained and sweetened as desired.
Use in medicine
Vitamin C is known to be a vitamin that has a wide range of positive effects on the entire human body because it strengthens the immune system and thus protects it from many infections, most notably from the flu and colds. Grapefruit is a large and important source of vitamin C.
In addition, grapefruit is a fruit rich in nutrients and has very few calories. It is one of the least caloric fruits. It also contains a decent amount of fiber and more than 15 useful vitamins and minerals. Half a medium-sized grapefruit contains about 52 calories, 13 grams of carbohydrates, 64% vitamin C, 28% vitamin A, 5% potassium, 4% thiamine, 3% magnesium. In addition, it is a rich source of some powerful plant antioxidants, which are responsible for many health benefits.
Another very important ingredient in grapefruit that has multiple health effects is folic acid. Folic acid is special as it helps the development of the fetus during pregnancy, has a beneficial effect on the brain, blood vessels, heart, act on fatigue, anxiety and depression. It has already been mentioned that grapefruit contains a certain amount of trains. Research shows that a diet rich in fiber-rich fruits helps induce a feeling of fullness. This is because fiber slows down the rate at which the stomach empties, increasing digestion time. Therefore, consuming adequate amounts of fiber can automatically help you eat fewer calories throughout the day, thus maintaining your appetite.
Consuming grapefruit can also reduce the risk of developing kidney stones. Also, citric acid from grapefruit can increase the volume and pH of urine, creating an environment that is more unfavorable for the formation of kidney stones.
Consuming grapefruit globally is thought to improve heart health by reducing risk factors for heart disease, such as high blood pressure and cholesterol because, as mentioned earlier, grapefruit is a fairly high source of potassium, a mineral responsible for many aspects of heart health.
History and facts
It is believed that grapefruit originates from the island of Barbados. It was considered a "forbidden fruit". In the 19th century, it was imported to the United States, specifically to Florida, where it began to be intensively cultivated, and then expanded production in the rest of the country. That is why Florida, i.e. the USA, is the largest producer of grapefruit today. Apart from there, grapefruit is also grown in Brazil, South Africa and China.
The story of how the fruit got its name is very interesting. A Jamaican farmer tasted grapefruit in the 1800s and said it tasted similar to grapes, thus calling it "grapefruit". That name has remained to this day. However, grapefruit did not acquire its status until the 1830s. Today there are different types of grapefruit.
Photo: Dan Ivanov / Pixabay