Natural History of the Date Palm Phoenix dactylifera

Natural History of the Date Palm Phoenix dactylifera

Index

Al Ain has a very special relationship with the Date Palm ( dactilyfera) * thanks to the wisdom of Sh Zayed. The modern city of Al Ain is unique due to three factors:

• it is built around oases that have been in production for some thousands of years
• not only have the oases been maintained but the Date Palm has also been planted in every main street and in many private gardens
• visitors are welcomed to the oases as places for recreation and to appreciate the immense value of the Date Palm. Oases have been upgraded to provide easy access as well as cafes and restaurants.

To better understand the Date I have researched a number of academic papers and other references to produce this profile. I did not set out to write an article but as I waded through mountains of references it made sense to share some of the information with ENHG members. I hope you can gain from it as much as I did over the many hours of reading.

It is difficult to know how far to go with such a profile. Ofcourse, some of the historic evidence must be simplified and may well be questioned, similarly, some of the statistical data concerning production is difficult to ratify. The many references I read all chose to differ concerning world production of dates, how many date palms there are and quantities of fruit produced anually. Even the number of Date Palms in UAE is the subject of debate. Translation of papers from Arabic to English can sometimes explain variations in facts and figures but, this problem is not peculiar to my paper.

I refer you to “Al Ain Oasis – An Introduction, Map & Guided Tour” by Phil Iddison (available from ENHG) for some more details of cultural traditions of the Date and the nature of oases.

History:

The Date Palm is recorded in ancient history extending over an area from the Indus Valley (now Pakistan) to Mesopotamia (now Iraq), the Nile Valley, Southern Persia, Eastern Mediterranean and the Horn of Africa. Historic records however, tend to describe the fruit without being able to say whether it is derived from a plant of cultivation or from a wild plant. Archaeobotanical evidence would have a difficult task to establish whether seed or other parts of a date palm were from domesticated or wild plants. References to the Date in the Nile Valley and Tigris/Euphrates valleys suggest it was a plant of cultivation along with other early developments in agriculture as it was found in an area where agriculture had been practised for 5 millennia.

Such a wide distribution implies that Phoenix dactylifera either evolved as a plant covering quite extensive geographic, soil and climatic conditions, which is unlikely, or it spread with the help of man after originating in a more limited geographic region. I support the theory of the Date being of Indus Valley origin (Geoffrey Bibby, “Looking for Dilmun”). Within the Indus Valley is found a sister specie, Phoenix sylvestris, (Sugar Date Palm, or Toddy Palm) which still occurs in the wild; its sap is used to produce a crude sugar.

Phoenix dactilyfera most likely grew wild in the Indus Valley as a natural hybrid of P.sylvestris where it was appreciated as a wild fruit and probably cultivated as early as the 6th millennia BC. Supposed wild occurrences of P.dactylifera in other locations is more likely to be man assisted, i.e. discarding of seed along trade routes and surrounding trade centres. Confirming the wild source of Phoenix dactylifera would make fascinating research.

From 5000 BC there have been finds of Date Palm seeds in association with human settlement. The oldest radiocarbon dated discovery of Date seeds was on Dalma island, part of the Abu Dhabi Islands group. Two seeds were found in 1998, the oldest was 5110 BC and the other, 4670 BC. As there was no evidence of cultivation of Date Palms in the region at that time, it is probable that these seeds came from traders.

The earliest evidence of Date Palm cultivation was during the Eridu period in Lower Mesopotamia. Date seeds were also found in the third millennia BC in the ‘Royal Cemetery” at Ur (Ellison et al. 1978: 171-2) but their origin is not established. The Sumerian words for date (zulum) and date palm (gishimmar) belonged to a group of words considered by Sumerologist Benno Landsberger to be non Sumerian loan words from a hypothetical pre- Sumerian language associated with a pre Sumerian aboriginal population. This suggests that The Date was known before the Sumerians and maybe it was an indigenous plant in that region.

In Bahrain in the time of early Dilmun, date seeds were found in burial chambers. In the region that is now south-eastern Iran, there were reliable finds of Date seeds of about 5th millennia BC. The earliest discovery was in the Indus Valley (now Pakistan) where silicified seeds of 6th millennia BC have been tested. Five thousand year-old seeds of the Date have been found in storage vases along the Indus River in the ‘Sind’ region. The botanical and geographic proximity of the sister specie P. sylvestris (Indian Sugar Date Palm) reinforces the argument that P. dactylifera also originated in the Indus Valley.

Dates without doubt were brought from the Indus Valley to trade with the Sabaeans and Shara of Southern Arabia from the beginning of trade for Frankincense.

City states of Saba’, Hadramawt, Qataban and Ma’in were rich from trade of Frankincense and Myhrr and were part of a trade route from India and East Africa. The Sabaeans cultivated the Date and it was a common food source. The earliest evidence of trade with what is now India and the southern Arabian Peninsula is during the time of the Queen of Sheba in the 1st Millennia BC, when the port of Aden was the entrepot for silk and other goods from the near East. The Queen of Sheba took Dates with her on the journey to meet King Solomon, a journey which initiated the intense and richly rewarding trade of Myhrr and Frankincense.

The Date was also widely traded at that time and was carried by camel caravans heading to Petra and beyond to the Mediterranean coast at Ghaza and accross the Empty Quarter to the Arabian Gulf at Bahrain. There is evidence of settlements along the Frankincense route, that grew various crops including Dates, to sustain travellers. The Shara people, the first Arabs, lived in the Dhofar region as early as 5000BC. They cultivated the Date Palm, as evidenced by stone age drawings of Date Palms found near modern day Salalah. The fruit accompanied trade caravans emanating from the region. The Shara still control the Frankincense industry in Dhofar.

The nomadic Bedouin people depended on the Date as a principal food source along with camel’s milk. Their Dates were purchased from oases or “aquired” by raiding parties ( The Bedu considered the raid “ghazw” to be an institution… “Our business is to make raids on the enemy, on our neighbour and on our brother, in case we find none to raid but a brother”..Anon.) . The nomadic Bedouin did not cultivate any plants however there were sedentary Arabs who were also Bedouins; they settled at oases around the edges of the vast empty deserts and grew Dates as well as grains.

The Temple of the Moon God in Ur, built between 4000 and 5000 years ago used Date Palm trunks in the construction. In the Magam region ( encompassing what is now UAE), trade of pearls and copper continued for thousands of years. It is perhaps enough to say that in those places where agriculture was believed to originate, including the Nile Delta, the Tigris and Euphrates delta, Bahrain, South West Persia and possibly Maga’m; Date Palms were cultivated and the Date was traded from as early as the 5th millennia BC.

While the Date Palm and its fruit were revered in several ancient cultures, it is the Arab culture that holds it in greatest esteem. The Prophet Mohammed who lived in a village at the centre of Date culture consecrated the fruit; they were his favourite food, described as ‘God’s Bounty’ in the Koran where it is mentioned no less than 26 times.

According to Islamic tradition, a Date tree was said to be the ‘Tree of Life’ in the Garden of Eden and to have sheltered (in another place) and provided a rich food source for Mary when she was pregnant with the Prophet Jesus.

There are many other references throughout history; all reinforcing the worth of the Date, some describing common and evidently successful medicinal uses. Such uses included a remedy for healing swollen limbs: fresh Dates, Date kernels, dry Myrrh, and bee’s wax were combined as a paste and applied to the swollen area for four days.

Fermented date juice reduced swelling and aching in legs of pregnant women. A remedy for sneezing required date juice to fill the nostril- - -stand back! A remedy to cure the heat of the heart required a mix of fresh dates, honey and sweet beer administered to the anus for four days! Stand further back!!

Of special interest is the remedy for accelerating hair growth; take the bone of a dog, Date kernels and a donkey’s hoof and boil with a jar of oil or fat – the delightful product was then used as a ungent. Date juice mixed with cinnamon and milk activates the formation of sexual desire. The application of a paste of Dates on poisonous bites gets rid of the poison effect. While it may be easy to laugh off some applications, medical research into the application of Date extracts is finding contemporary uses which reinforce many of the ancient’s remedies.

The species Phoenix dactilyfera has about 19 known relatives including Phoenix canariensis (Canary Island Palm), P. reclinata (Senegal Date Palm) and P. sylvestris (Indian Sugar Date Palm). All are members of the plant family, Arecaceae. The scientific name was derived from ‘Phoenix’, the legendary bird of ancient Greece. The Phoenicians died cloth a purple colour from the Murex shellfish; this colour was also called Phoenix, possibly because it had such great appeal and value. The same colour was noted on the fruit of the date, hence the Date Palm genus became Phoenix and the specific name dactylifera came from the shape of the fruit, ‘dactylos’ being the ancient Greek word for ‘finger’. Well before the scientific name was generally applied, there were many other common names used including ‘Tamr’ that is still applied to the final dried state of the Date fruit.

The species, Phoenix sylvestris (Indian Sugar Date Palm) has been confirmed by detailed systematic analysis as the nearest sister species to P. dactylifera and possibly an early stage in the evolution of P. dactylifera. P. sylvestris still grows wild in Pakistan and India. This association strongly suggests that the Indus Valley was the source of the Date Palm and from there it spread eastward to Mesopotamia, Egypt, Dilmun, Magam etc. along sea and land trade routes as early as the 6th millennia BC.

Date Palms are dioecious; i.e. the male and female parts are on separate plants. The Date Palm is the tallest of the Phoenix species growing to 30m in some places. The trunk, in cultivation, is surrounded from the ground upward in a spiral pattern of leaf bases. The leaves are large, 4-5m, alternate, sheathing in dense terminal rosettes, pinnately lobed. The ends of leaf fronds are needle sharp to help protect the growth tip from grazing animals.

The fruit is also the largest of the species, with a few varieties reaching up to 100mm x 40mm in size. P.dactylifera is now found in tropical and sub tropical regions all over the world as well as in temperate and arid regions in USA, Australia, southern Spain and the Mediterranean coast of Africa and West Asia. The fruit is a ‘drupe’ with a single seed in each. Fruit is borne on clusters often weighing 10 kg or more. A fully productive palm can support up to 10 clusters carrying as much as 100kg of fruit.

From the time of pollination, the fruit takes 200 days to reach the Tamr stage when the fruit is fully ripened. During ripening, the fruit passes through several stages beginning with:

• Hababauk which is the week during which the female is pollinated.
• Kimri follows and lasts for 9 weeks when the fruit is rapidly filling out and is 85% water. During this stage, the fruit is green and hard.
• Then there is Khalaal when weight gain slows, moisture level drops to 50 to 60%, sugar content rises and the fruit colours. Modern date producers can harvest at this stage; some put the fruit in cold storage and allow further ripening to occur in the market place after removal from storage.
• Traditionally, the fruit remains on the tree either until the Rutab stage, when the fruit turns brown, reduces weight due to moisture loss (moisture level of 35 to 40%) and softens. In the local market the Rutab stage (often very early in this stage) is mostly what is offered from July through to September as different varieties reach Rutab.
• Some fruit is left on the tree until it reaches Tamr, a dried, brown date with 20 to 24% moisture content. This fruit is harvested and sent for processing, packaging or value adding as confectionery. Harvesting can also be at early Rutab stage; then the fruit is spread out on mats for further drying to Tamr stage.

Market stall attendants will be impressed if you show your knowledge of ripening stages and if you can distinguish the differences in varietal flavour and texture.

The Date Palm has adapted to areas with long, dry summers and mild winters, where it is dependent on man for irrigation. It has unique characteristics that enable it to thrive in sand without being aranaceous and to grow well where water is close to the surface without being aquatic.

It has been said that the Date Palm ‘must have its feet in running water and its head in the fire of the sky’. Some varieties can survive with water of 22000ppm total dissolved salt however their fruit productivity would be very low. Water with salt levels of 3000ppm is a preferred upper limit for good productivity. Even at this level, salt can accumulate on the soil surface and must be removed either by leaching or by labour. Date Palms begin their productive life at between 5 and 8 years; they reach maturity at 30 years and begin to decline at 100 years.

The principal need is water, which, for mature palms, can be as little as 70 litres every ten days in winter and as much as 70 litres every two days in summer. Keeping the irrigation system in good repair is ofcourse, paramount. The other main tasks are fertilizing, trimming of old leaves, pollination, thinning of fruit bunches, tying of bunches to leaf stalks (to limit movement and thereby reduce fruit drop due to wind), harvest, cutting and planting of suckers and weed control for young palms. Harvest and transport of fruit to the market and processing centres is the culmination of all aspects of Date palm culture. Pest control is a continuing process with the main offenders being red palm weevil (Rhyhchphorus ferrugineus), the root knot nematode (Meloidogyne incognita), termites (Psammotermes hypostoma), date scale (Parlatoria blanchardii), date moth (Batracchedra amydraula) and mealy bug (Dysmicoccus brevipes). Methods of control are beyond the scope of this paper.

Fungal infections such as Fusarium and Phytophthora are generally associated with borer activity, creating access for fungal spores to the interior of the palm. Borer and termites work at the degeneration of the palm trunk, nematodes work at the roots, weevils work on the fruit, scale and mealy bugs suck the sap from the leaves- and we are supposed to be sympathetic toward bugs! You may have noticed, or you will notice, during March, a syrupy substance covering the ground under date palms in some of the old oases of Oman. There is little attempt to control the cause in these oases because of the very low overall income generated by these farms.

In addition to the syrupy substance, the palm leaves also have a black covering and the whole scene is quite depressing. This is caused by a scale insect that sucks the sap from the palm leaves and at certain times of the year it is very active and exudes a sweet syrupy substance. The syrup provides a perfect food for certain moulds which have black fruiting spores produced in vast numbers. Ants also feed on the syrup and even farm the scale by carrying them to other palms and stroking the abdomen of the scale insects to stimulate the production of sweet exudate. Some other sap-sucking insects can also produce this exudate, e.g. aphids

From its most fundamental attribute, a giver of shade, the Date Palm has and continues to provide for man in so many of the world’s hottest regions, something easily appreciated when visiting Al Ain’s oases.

There is evidence of the trunk being used as a structural timber in the Nile Valley 5000 BC (Kharga Oasis, Western Desert) the fronds have been woven to line ceilings, to provide mats, to provide utensils for carrying possessions and for covering food. Date fronds woven as Barrasti structures as shelters and as wind breaks are still common place. In predynastic Egypt (c.3500BC), in Ruzikate (Sharkia Province) excavations revealed a mummy robed with date palm leaves. The fruit is the jewel in the crown and provided a major source of food for desert dwellers, mariners, armies, nomads and caravan travellers and for domestic animals for at least 7000 years. It is the oldest cultivated tree in the history of man. The fig, olive, grape and pomegranate were also cultivated very early in man’s settlement. Dried Dates are one of the few food sources which is self preserving (because of its high sugar content), is light to carry, especially in view of the small quantity needed for daily consumption, and is pleasant to eat. Dried fish and other dried meats are less palatable and grains require preparation before they can be eaten. From earliest records of predynastic Egypt the fruit was used as a beer sweetener (excavation of a vat in Hierakonpolis, Upper Egypt, 3450 BC).

The microbiological integrity of the Date fruit means that they are easily incorporated into various foods. The fruit contains most of the dietary elements including easily digested sugars, glucose, sucrose and fructose, proteins, fats and minerals, especially Iron, Magnesium, Copper, Potassium, Sulphur and vitamins including riboflavin, thiamine, biotic, folic and ascorbic acid.

• Normally, Dates are free of pesticide contamination and may be marketed as organic food.
• They have a desirable sugar/acid ratio that provides a fruity/sweet taste and flavour enhancing qualities.
• Dates act as humactants due to the presence of reducing sugar, fructose, which helps in extending shelf life and freshness of snack foods and chocolate bars. When mixed with dough it keeps the softness quality of the bread.
• Date paste is a natural extrudable product easily incorporated as a filler in bakery products and displaces the need for artificial preservatives and additives
• Date paste can be easily shaped and binds ingredients together, like nuts, grains and other snack bar ingredients. Date syrup or paste is a common ingredient of certain halwa.
• Syrup extracted from Dates has a higher sweetening (taste) power than sucrose and is therefore suitable as a refined sugar replacement with a lower total calorie level.
• The syrup is also a better source of energy in sports drinks
• Animal feed with very high overall dietary value and low waste content
• Date seed ground as food for fish farms

There are many other applications and uses of whole fruit or extracts but the fruit itself is still the most widely consumed, either fresh, dried or value added by filling with almonds or coating with chocolate etc. Some interesting uses, many may not be aware of, include vinegar production, a component of ketchup and mayonnaise; the alcoholic beverage arak is produced from dates; fuel oil from the seeds and for the microbiological industry Date extracts provide- organic acids, enzymes and a component for some antibiotics. As an aside, the Bedu people have a low incidence of all forms of cancer, which some medical research links to the level of Date consumption.

Production levels and locations:

The FAO estimate world-wide production of Dates, peaked in 1996 at 4,492,000 tons. The worlds largest producer is Iran at 765,000 MT followed by Egypt (680,000MT), Saudi Arabia (597,000MT), Iraq (550,000MT), Pakistan (533,000MT), Algeria (361,000MT) then UAE at 240,000MT. Other significant producing countries are Libya, Morocco, Sudan, Tunisia, China, Oman, Yemen, Qatar, Bahrain, USA and Jordan. Turkey and Spain produce small quantities but Spain is of particular interest because the Moors introduced the Date there and subsequently the Spanish took it to Mexico and from there it migrated to California. Major commercial plantings in California were however, imported some time later, direct from Saudi Arabia.

In UAE, the Abu Dhabi Emirate is by far the largest producer of Dates. There is said to be approximately 16 mill Date Palms in the Emirate with approximately 4 mill in the remaining six Emirates. Of Abu Dhabi’s 16 million, only 6 million are currently producing. A huge number of the above are young date palms growing on the many hundreds of new farms created at the instruction of Sh Zayed. These palms will not produce significant crops for another 3 to 5 years, when they do, based on the figure of 16 million, UAE’s production could match that of Saudi Arabia. Of special interest to readers would be the number of producing date palms in the various oases of Al Ain region. There is a total of 1.108 mill producing palms in the region extending to Al Khazna on the Abu Dhabi Road and to centres such as Al Hayer and Al Faqar in the Dubai direction. Al Ain has 24 separate districts and there are new farms being added in places like Mubazzarah, below Jebel Hafeet, where the palms will not come into significant production until 2005. At that stage, the Al Ain region may produce 4 to 5 times what it does now.

Al Ain Oasis has 60,000 palms and Al Jimmi/Qattara Oasis has 103,000. Within the streets of Al Ain there would be approx. 25,000Date Palms all of which are harvested and contribute to the overall regional crop.

While Dates grow readily from seed, the quality of the resultant plant and the reliability of its crop is too ‘hit and miss’ therefore the most common method of reproduction is the planting of suckers. There have been further refinements in propagation methods including, over the last 20 years production of ‘tissue culture’ dates in laboratories in various parts of the world including unlikely locations like Surrey in England.

Tissue culture enables the rapid reproduction of selected clones which is far more reliable than seed reproduction and much quicker than the sucker method, especially when most palms produce between 1 and 20 suckers in a lifetime. The traditional sucker propagation method passes on pests and diseases and also ensures that the substantial improvement of plantation quality is a slower process. Many of the palms in old oases in Buraimi for example, are 100 years or more old and suffer from low productivity. Many of the old varieties are no longer in favour, fetch a low price and are mostly used as stock feed. Without substantial replanting, these oases will continue to decline as productive farms and will correspondingly decline as places of aesthetic quality.

Oases are made up principally of female palms, as they are the ones carrying the fruit. Plantations have palms spaced at approximately 8m apart which means there are just under 150 palms per hectare. Usually there is one male for every 30 or 40 females. The males must also be carefully selected; some oases are now being planted without any male plants because the high quality pollen can be imported. Even now, it is not uncommon for growers to select spathes of male pollen from the market and use that if it is superior to whatever they may have on the few male palms maintained within their plantations. The spathes containing pollen appear in February/March and from then until early April there is a frantic period of man aided pollination, both by hand and by mechanical blowers. Nature depends on wind and some insect vectors to undertake such a task; such means would result in a very low level of fertilization certainly insufficient for commercial production.

The writer enthusiastically purchased a male spathe early this season after noticing that the palm at home was starting to flower. Only problem was that it also turned out to be a male. No problem, I also have a small female (has produced a few dates before) which, will be pollinated next year with the same pollen (it stores for two to three years without losing viability). By July there are Date Palms all over Al Ain displaying fine bunches of ripening dates (Rutab), some early varieties are already ripe and can be found in the fruit and vegetable market along with small numbers of imported varieties (which may surprise some people). Tastes are so varied here that there is a desire to offer as wide a range as possible to the discerning buyers). Early varieties ripen to Rutab in late June but most are ripening from July through August and some are still around as late as October. In this region, those dates that don’t go direct to the fresh fruit market are sent to the Al Ain Date Factory where the growers receive a known fixed price for their dates, depending on the variety, the condition of the fruit and the weight. Such price fixing allows greater certainty for the grower when he is making decisions about development of his farm.

There are more than 600 varieties, including cultivars, grown world-wide and different countries have their favourites. In UAE the preferred fruit is Khalas but others such as Zaghloul, Khuneizi, Hilali, Howaiz, Naghal and Jaberi Fardh, have their followings. They have different colours, flavours, sweetness, acidity and textures. A popular imported variety, mainly from Morocco, is Majool, which is a very large fruit. All major date producing countries have their own cultivars and favoured varieties, such as Amir Hajj and Ashrashi from Iraq; Saidy and Hayany from Egypt, Deglet Noor and Thoory from Algeria. Ruzeiz, Bukeira, Nebut, Seif and Barhi from Oman. You should make a point of checking the markets and the specialist date shops to identify different varieties and their flavours.

It is too easy to associate such an ancient fruit with equally ancient agricultural practices - not so. While some plantations still follow traditional methods, the Date industry is as sophisticated as most other forms of agriculture. There is considerable research and experimentation in plant breeding not only to improve fruit characteristics but also to increase the plant’s resistance to weevil and nematode. Other research continues in uses of Date fruit, control of storage pests, improved fruit storage methods, as well as pest control, irrigation methods/ application rates, plant nutrition and general plant and soil management. Research into wider applications for date extracts in medicines and dietary products also continues.

Proceedings from “The First International Conference on Date Palms” UAE University, Faculty of Agricultural Sciences, Dept. of Plant Production. Al Ain 1998.

 

Prof Hamad Abdel-reheem Ead “The Date Palm in Ancient History”. (Prof Hamad is Professor of Chemistry, Faculty of Science, University of Cairo and Director of the Science Heritage Centre.

 

Yaarub Al Yahya “Biotechnology and Date Palm Development” (Yaarub is from Wye College, University of London).

 

Rashid Al Yahyai “ The Traditional Date Palm Cultivation in Oman” (Rashid is at Cornell University? department.)

 

W.H. Barreveld “Date Palm Products”, FAO Rome, 1993.

 

Beech M. and Shepherd E. “Archaeobotanical evidence for early Date consumption on Dalma Island, United Arab Emirates”, Antiquity 75 (2001): 83-9

 

Ali Ahmad Al Shahri “The Language of Aad” (Essentially this book is the story of the Sharha, first Arabs and their language, Sharhi) - privately published in 2000- difficult to find.

Footnote

{* The correct use of botanical names is for the Genus to have a capital first letter and the species to be a lower case and distinguished in some way e.g. in italics. Subsequent use of the Genus can be abbreviated to the first letter. Common names e.g. Date Palm or Date should also begin with a capital letter. Such consistency makes the study and application of botany much easier to follow.} Return to text