PLB143: Evolution of Crop Plants . Instructor: P. Gepts

The crop of the day:

The Date, Phoenix dactylifera

(photo from ArabNet, Saudi Arabia Tour Guide: Al Madinah - City of Palms)

© Paul Gepts 2002

"There is among trees one that is pre-eminently blessed, as is the Muslim among men; it is the date palm." Muhammad 

Sources of information

Note: Unless otherwise mentioned, date palm images from Botanik Online of the Fachbereich Biologie, Universität Hamburg or the Israeli Botanical Society Album of Plants of Israel

The date palm, its botany

  • Tall evergreen, unbranched palm; can grow to 30 m
  • The trunk is surrounded from the ground upward in spiral pattern with the base of earlier formed leaves (leaf scars).
  • Leaves are large (4-5 m) alternate, sheathing, in dense terminal rosettes, pinnately lobed. The end of the leaf fronds are needle sharp.
  • Dioecious: female and male individuals. Flowers are borne in bunches at the top of the tree. Only the female trees produce fruit, but one male tree can produce enough pollen to pollinate 40-50 female trees.

  • The fruit of the date is a drupe and has one seed, which can vary in size, shape, color and quality of flesh. Unripe dates are green in colour, maturing to yellow, then reddish-brown when fully ripe. A single large bunch may contain more than a thousand dates, and can weigh between 6 to 8 kg. 
  • Each tree produces between five and ten bunches. A mature female tree can produce upwards of 150 pounds of fruit annually.
  • Date palms begin to bear fruit at 3 to 5 years, and are fully mature at 12 years.
  • Can be propagated by seed (but the chances are 50/50 of getting a male tree); generally, however (i.e. in commercial planting), propagated by suckers (offshoots) taken from the base of the mature female (>< other Phoenix species). These will always be a genetic copy of the parent tree.

The date palm, its distribution and ecology

  • Requires high temperatures and low air humidity for fruit setting and ripening (35 C is optimum temperature for pollen germination); also requires water supply (irrigation, high water table) ("growing with its head in fire and its feet in water"!).
  • Grown in a nearly rainless belt between 15 and 35 N Lat in Sahara and southern fringe of the Near East (Arabia Peninsula, souther Iraq, Jordan, etc.)
  • Wild dates are morphologically and ecologically similar to domesticated dates but have smaller, inedible fruits. There are many escapes from cultivation and hybrids between wild and domesticated dates, making a distinction between wild and domesticated populations quite difficult.
  • Remnants of wild populations may still be present in areas of Jordan and the Iran-Iraq border.

The date palm, its archaeology

  • Earliest finds: 5000-6000 BC, from Iran, Egypt, Pakistan: probably wild
  • Earliest cultivated find: 4000 BC from Eridu, Lower Mesopotamia (Bronze Age)
  • Mentioned in Akkadian and Sumerian cuneiform sources: 2500 BC and later
(Date palm representation an ancient synagogue in Kfar Nahum, Israel, 3-5 century CE; from Plants and Judaism, Dept. of Plant Sciences, Tel Aviv University )
Date palm representation on ancient synagogue

The date palm, its uses

  • Every part of the tree has its uses. The wood and leaves provide timber and fabric for houses and fences.
  • The leaves are used for making ropes, cord, baskets, crates and furniture. Bases of the leaves and the fruit stalks are used as fuel.
  • The fruit yields food products such as date vinegar, date chutney or sweet pickle, date paste for bakery products and additional flavoring for oranges, bananas and almonds. The Arabian-flavoured Bedouin dish known as Canua and roasted whole date seeds are popular as far away as Libya. Even the tree's terminal buds (heart of palm) make tasty additions to vegetable salads.
  • The date palm is often the only available staple food for the inhabitants of desert and arid lands, and as such it is vital to millions throughout North Africa and the Middle East. According to the World Food and Agricultural Organisation, there are 90 million date palms in the world and each tree can grow for more than 100 years. 64 million of these trees are grown in Arab countries, which produce 2 million tons of dates between them each year.
  • Trees start producing after 4-5 years and reach full production after 10-12 years.
  • Date-producing Arab countries are Algeria, Bahrain, Egypt, Iraq, Libya, Morocco, Oman, Saudi Arabia, Sudan, Syria, Tunisia, the UAE, and Yemen. Between them Algeria, Egypt, Libya, Morocco, and Saudi Arabia produce 600 different kinds of dates, which accounts for 60% of the world's production. In Saudi Arabia, Madinah's date market (Souq Al Tumoor) contains about 150 varieties, the most popular of which is Anbara, the most expensive.
  • Dry or bread dates: self-curing on tree. Soft dates: require harvest at appropriate time and sun-drying to increase sugar content and prevent spoilage. The latter are packaged traditionally in palm leaves and widely traded (caravans, ships)
  • The date palm is also highly prized as an ornamental tree, as it is ideally situated in streets, avenues and driveways. Optimum planting conditions dictate that trees should be set 6-8m apart and then well soaked with water. The date palm can tolerate a high salinity level of up to 22,000 parts per million.
  • Iraq is the top commercial producer and exporter of dates, closely followed by Saudi Arabia, Egypt and Algeria.

The date palm, its historical and religious references

  • Important in ceremonies of Judaism, Christianity, and Islam
  • Fronds used on Palm Sunday, commemorating the entry of Jesus in Jerusalem (Lion's Gate or east entrance to Jerusalem, through which Jesus is supposed to have entered the city)
  • According to the Qur'an, dates have always been considered beneficial to mothers. When Mary gave birth to the Prophet Jesus (may peace be upon Him) under a palm tree, she heard a voice telling her:
    "Shake the trunk of the palm tree towards thee: it will drop fresh, ripe dates upon thee. Eat, then, and drink, and let thine eye be gladdened!" (Qur'an 19:25-26)
  • Introduced into Spain by Moors
  • Introduced by Spanish into Americas; log-term plantations only on coastal area of Peru and Baja California (dry climates)
  • Modern date production in U.S.: clones obtained directly by USDA in Near East and North Africa and planted in Coachella valley (CA): e.g., Leading cultivar, Deglet Noor, from Biskra oasis in Algeria.

The date palm, its nutritional benefits

  • The sugar content of ripe dates is about 80%; the remainder consists of protein, fat and mineral products including copper, sulphur, iron, magnesium and fluoric acid. Dates are high in fiber and an excellent source of potassium.
  • Five dates (approx. 45 grams) contain about 115 calories, nearly all from carbohydrates.
  • Bedouin Arabs, who eat them on a regular basis, show an extremely low incidence rate of cancer and heart disease.