Watermelon is an annual plant with a creeping development, a broad but shallow root system and thin, striated and rough stems. Its divided leaves with 3-5 rounded lobes and its flowers are yellow, monoecious. Its fruits are spherical or oblong peponids, with a variable weight that can reach 15Kg. They usually have a smooth or striped green rind, although the pulp varies in color depending on the cultivar, and can be red, pink or yellow.
In Spain some 21,000 hectares are cultivated, with an approximate production of 1,000,000 tons of sandays. Less than half of the total production is exported, 300,000 hectares. The main provinces with the most production are Almería, Valencia and Murcia.
Watermelon achieves better performance in soils of medium texture and rich in organic matter. It is able to grow correctly both in slightly acid soils with a pH of 5 to 6.8 and in moderately alkaline soils. In relation to water stress, it is slightly sensitive to salinity.
Being a thermophilic plant, watermelon benefits if it grows in environments with temperatures of 24-32ºC. At much higher temperatures (40ºC) they can suffer burns on the skin and get sun burns. It is very sensitive to frost, and can lose part of the production, even if they are slight.
Watermelon is a plant that, although it can be adapted to dry farming, it is preferable to do so in irrigated areas to reach its maximum productivity. Its maximum water requirement is between the end of its vegetative development to the fruit fattening stage.
In Spain there is a high variety mainly due to hybridization. They are characterized according to cultivar. Among those with round / oval fruit we have those with dark green rind and red pulp (Valenciana Común de Semilla Negra, Sugar Baband, Fabiola, Perla Negra, Agua Dulce, Fashion Sin, etc.) and those with grated rind (Crimson Sweet, Meridian, De la Reina, Sweetness, Imperial, Emerald, Queen of Hearts, etc). Of varieties with large ellipsoidal fruits and red pulp, the Oden, Blacklee, Charleston Graand or Crimson Grant varieties among others. There are also cultivars with yellow flesh, such as the variety Andellow Doll, Sorpresa or Chiffon.