Watermelon (Citrullus lanatus) is a flowering plant species of the Cucurbitaceae family and the name of its edible fruit. A scrambling and trailing vine-like plant, it is a highly cultivated fruit worldwide. With more than 1,000 varieties.

Pritish Kumar gives an illustration about Watermelon, a flowering plant species of the Cucurbitaceae family.

It is grown in favourable climates from tropical to temperate regions worldwide for its large edible fruit. Which is a berry with a hard rind and no internal divisions, and is botanically called a pepo. The sweet, juicy flesh is usually deep red to pink, with many black seeds. Although seedless varieties exist. The fruit can be eaten raw or pickled, and the rind is edible after cooking. It may also be consumed as a juice or as an ingredient in mixed beverages.

Description

The watermelon is an annual that has a prostrate or climbing habit. Stems are up to 3 meters (10 feet) long and new growth has yellow or brown hairs. Leaves are 60 to 200 millimeters (2+1⁄4 to 7+3⁄4 inches) long and 40 to 150 mm (1+1⁄2 to 6 in) wide. These usually have three lobes that are lobed or doubly lobed. Young growth is densely woolly with yellowish-brown hairs which disappear as the plant ages.

Like all but one species in the genus Citrullus, watermelon has branching tendrils. Plants have unisexual male or female flowers that are white or yellow and borne on 40-millimetre-long (1+1⁄2 in) hairy stalks. Each flower grows singly in the leaf axils, and the species’ sexual system, with male and female flowers produced on each plant, is (monoecious). Male flowers predominate at the beginning of the season; the female flowers, which develop later, have inferior ovaries. The styles are united into a single column.

The large fruit is a kind of modified berry called a pepo with a thick rind (exocarp) and fleshy center (mesocarp and endocarp). Wild plants have fruits up to 20 cm (8 in) in diameter, while cultivated varieties may exceed 60 cm (24 in). Rind of the fruit is mid- to dark green and usually mottled or striped, and the flesh, containing numerous pips spread throughout the inside, can be red or pink (most commonly), orange, yellow, green or white.

Cultivation

Watermelons are plants grown in climates from tropical to temperate, needing temperatures higher than about 25 °C (77 °F) to thrive. On a garden scale, seeds are usually sown in pots under cover and transplanted into well-drained sandy loam with a pH between 5.5 and 7, and medium levels of nitrogen.

Major pests of the watermelon include aphids, fruit flies, and root-knot nematodes. In conditions of high humidity, the plants are prone to plant diseases such as powdery mildew and mosaic virus. Some varieties often grown in Japan and other parts of the Far East are susceptible to fusarium wilt. Grafting such varieties onto disease-resistant rootstocks offers protection.

The US Department of Agriculture recommends using at least one beehive per acre (4,000 m2 per hive) for pollination of conventional, seeded varieties for commercial plantings. Seedless hybrids have sterile pollen. This requires planting pollinizer rows of varieties with viable pollen. Since the supply of viable pollen is reduced and pollination is much more critical in producing the seedless variety, the recommended number of hives per acre (pollinator density) increases to three hives per acre (1,300 m2 per hive).

Watermelons have a longer growing period than other melons, and can often take 85 days or more from the time of transplanting for the fruit to mature. Lack of pollen is thought to contribute to “hollow heart” which causes the flesh of the watermelon to develop a large hole, sometimes in an intricate, symmetric shape. It suffering from hollow heart are safe to consume.

Farmers of the Zen Tsuji region of Japan found a way to grow cubic watermelons by growing the fruits in metal and glass boxes and making them assume the shape of the receptacle. The cubic shape was originally designed to make the melons easier to stack and store, but these “square watermelons” may be triple the price of normal ones, so appeal mainly to wealthy urban consumers. Pyramid-shaped watermelons have also been developed and any polyhedral shape may potentially be used.

Varieties

The more than 1,200 cultivars of watermelon range in weight from less than 1 kilogram (2+1⁄4 pounds) to more than 90 kg (200 lb); the flesh can be red, pink, orange, yellow or white.

1)’Carolina Cross’ produced the current world record for heaviest watermelon, weighing 159 kg (351 lb). It has green skin, red flesh and commonly produces fruit between 29 and 68 kg (65 and 150 lb). It takes about 90 days from planting to harvest.

2) ‘Golden Midget’ has a golden rind and pink flesh when ripe, and takes 70 days from planting to harvest.

3) ‘Orangeglo’ has a very sweet orange flesh, and is a large, oblong fruit weighing 9–14 kg (20–31 lb). It has a light green rind with jagged dark green stripes. It takes about 90–100 days from planting to harvest.

4) ‘Moon and Stars’ variety was created in 1926.[38] The rind is purple/black and has many small yellow circles (stars) and one or two large yellow circles (moon). The melon weighs 9–23 kg (20–51 lb). The flesh is pink or red and has brown seeds. And the foliage is also spotted. The time from planting to harvest is about 90 days.

4)’Cream of Saskatchewan’ has small, round fruits about 25 cm (10 in) in diameter. It has a thin, light and dark green striped rind, and sweet white flesh with black seeds. This can grow well in cool climates. It was originally brought to Saskatchewan, Canada, by Russian immigrants. The melon takes 80–85 days from planting to harvest.

4) ‘Melitopolski’ has small, round fruits roughly 28–30 cm (11–12 in) in diameter. It is an early ripening variety that originated from the Astrakhan region of Russia, an area known for cultivation of watermelons. The Melitopolski watermelons are seen piled high by vendors in Moscow in the summer. This variety takes around 95 days from planting to harvest.

5) ‘Densuke’ watermelon has round fruit up to 11 kg (24 lb). The rind is black with no stripes or spots. It is grown only on the island of Hokkaido, Japan, where up to 10,000 watermelons are produced every year. In June 2008, one of the first harvested watermelons was sold at an auction for 650,000 yen (US$6,300), making it the most expensive watermelon ever sold. The average selling price is generally around 25,000 yen ($250).

Many cultivars are no longer grown commercially because of their thick rind, but seeds may be available among home gardeners and specialty seed companies. This thick rind is desirable for making watermelon pickles, and some old cultivars favored for this purpose include ‘Tom Watson’, ‘Georgia Rattlesnake’, and ‘Black Diamond’.

Food and beverage

Watermelon is a sweet, commonly consumed fruit of summer, usually as fresh slices, diced in mixed fruit salads, or as juice. Watermelon juice can be blended with other fruit juices or made into wine.

The seeds have a nutty flavor and can be dried and roasted, or ground into flour. Watermelon rinds may be eaten, but their unappealing flavor may be overcome by pickling, sometimes eaten as a vegetable, stir-fried or stewed.

Citrullis lanatus, variety caffer, grows wild in the Kalahari Desert, where it is known as tsamma. The fruits are used by the San people and wild animals for both water and nourishment, allowing survival on a diet of tsamma for six weeks.

Nutrients

Watermelon fruit is 91% water, contains 6% sugars, and is low in fat .

The amino acid citrulline is produced in watermelon rind.

In a 100-gram (3+1⁄2-ounce) serving, watermelon fruit supplies 125 kilojoules (30 kilocalories) of food energy and low amounts of essential nutrients. Only vitamin C is present in appreciable content at 10% of the Daily Value. Watermelon pulp contains carotenoids, including lycopene.

Reference

https://en.wikipedia.org/wiki/Watermelon