CHAPTER II: ORIGIN, GEOGRAPHICAL DISTRIBUTION AND NUTRITIONAL VALUES OF DATE PALM

by A. Zaid and P.F. de Wet
Date Production Support Programme

1. Origin of date palm

The exact origin of the date palm (Phoenix dactylifera L.) is considered to be lost in Antiquity. However, it is certain that the date palm was cultivated as early as 4000 B.C. since it was used for the construction of the temple of the moon god near Ur in Southern Iraq - Mesopotamia (Popenoe, 1913; 1973).

More proof of the great antiquity of the date palm is in Egypt's Nile Valley where it was used as the symbol for a year in Egyptian hieroglyphics and its frond as a symbol for a month (Dowson, 1982). However, the culture of date palm did not become important in Egypt until somewhat later than that of Iraq (Danthine, 1937), about 3000 - 2000 B.C.

The above is confirmed by history, and corroborated by the archaeological research into ancient historical remains of the Sumerians, Akadians and Babylonians (Figure 17a). Houses of these very ancient people were roofed with palm tree trunks and fronds. The uses of date for medicinal purposes, in addition to its food value, were also documented.

In conclusion, date palm is probably the most ancient cultivated tree in the world. It could be safely assumed that the reason for mentioning dates and date palms in the Jewish, Christian, and Islamic religions was due mainly to the influence of the Prophet Abraham, who was born and raised in the old city of Ur where date palms were grown. Ibrahim's love of the date and date palm left a lasting influence on these religions.

The Jews consider the date as one of the seven holy fruits and they celebrate Palm Sunday. But no other religion has stressed the holiness of the date and date palm as much as the Islamic religion. The Holy Koran mentioned date and date palm in 17 Suras (chapters), of the original 114 Suras and 20 verses of 6,263 verses. Prophet Muhammed (peace be upon him) is reported to have said that the best property is date palm, that dates cure many disorders, and he urged Muslims to eat the date and tend the date palm. "And they came to Elim, where were twelve wells of water and three score and ten palms, and they encamped there by the waters". Elim was one of the oases where the Israelites set up camp during their flight from Egypt across the Sinai to the Promised Land, and the 70 palms mentioned in the book of Exodus, 45:27, were date palms.

During Biblical times, the date palm was common throughout Egypt and the Levant, including present-day Israel. Phoenicia, the name by which part of the Levant, particularly the portion including Tyre and Sidon, was known to the Romans and Greeks, means "land of palms". Some of the ancient coins of Tyre and Sidon bear the image of the date palm, as does a Jewish coin issued at the time of Judas Maccabeus, about 175 B.C. To commemorate the conquest of the Jews and the destruction of Jerusalem by Titus in 70 A.D., the Roman emperor Vespasian issued a coin showing a weeping woman sitting beneath a palm tree.

Flavius Josephus, a Jewish historian, reported that during his time (First Century A.D.) there were still groves of date palms near Jericho, around the lake of Galilee, on the Mount of Olives, and in and around Jerusalem. In passing, it may be said here that the Hebrew word for the date palm is "tamar". It became the Jewish symbol of grace and elegance and was often bestowed by them on women, as for instance, the sister of Absalom, in allusion to their graceful, upright carriage. Even today, in Israel and other countries "Tamar," "Tamara," and "Tamarah" are often used as girls' names.

The legend is, that the date palm (not the apple tree) was the tree of knowledge of good and evil, and that the date (not the apple) was the fruit Eve so generously offered to Adam in the Garden of Eden (Figure 17b). If the date palm was the tree of knowledge, Gabriel would not have suggested to Adam that he taste and eat the dates.

Where the date palm originated is not known. Although widely cultivated, no truly wild plant has ever been found. Its progenitor is believed to be Phoenix reclinata Jacq from tropical Africa, or Phoenix sylvestris (L). Roxb. from India, or a hybrid between these two. Both these species have palatable, although inferior fruits.

The spreading of the date palm and its cultivation occurred during the past centuries following two distinct directions:

- One starting from Mesopatamia to Iran, to reach the Valley of the Indus and Pakistan;
- The other starting from Egypt towards Libya, the Maghreb and Sahel countries (Figure 18).

The original establishment of date palm in these countries was initially localised: Tunisia/Djerid; Algeria/Souf, Oued Rhir, Tidikelt and Saoura; Morocco/Tafilalet and Draa Valleys; and Mauritania/Adrar.

To the south, it was introduced into Mali/Tassili, Hoggar and Adrar of Iforas; Niger/Djado-Kaouar; and Chad/Borkou-Tibesti.

The above date propagation in Africa was realised using the same itineraries as those of the Neolithic civilisation but with some delays. It is illustrated by the presence of Sudan date plantations around the Neolithic sites.

The establishment of date plantations and oases was made possible because of the development of irrigation techniques. This establishment in the Sahara was initiated during the last centuries before our era. The optimum development was only reached during the Fifth and Sixth centuries with Botros and Zenets when commercial camel traffic through the Sahara was made possible.

The old world of date palm stretches from east to west (± 8,000 km) and from north to south (± 2,000 km). According to Dowson (1982), date palm covers 3 % of the world's cultivated surface.

In the early years of the Nineteenth Century (1912), the date palm was introduced into the western part of North America (Colorado Desert, Atacama Desert and other regions).

2. Geographical distribution of date palm

Date palm is found in both the Old World (Near East and North Africa) and the New World (American continent) where dates are grown commercially in large quantities (Figure 19). The date belt stretches from the Indus Valley in the east to the Atlantic Ocean in the west. In order to have a clear picture on the geographical distribution of date palm, it is worth looking at it from the following aspects: (i) Distribution according to latitude, (ii) Distribution according to altitude, and (iii) Number of date palms in the world.

(i) Distribution according to latitude

The distribution according to latitude for both northern and southern hemispheres is illustrated in Tables 6 and 7. In Asia, 32° north, in the Indus Valley, is the northern limit of date palm cultivation. It follows the southern edge of the Perso-Afghan mountain mass, till it reaches the 35° north in Iraq and turns south west to the Mediterranean sea at the Gulf of Gaza. Date palm then follows the Mediterranean coast as far as Tunisia and skirts the southern edge of Morocco to the Atlantic Ocean.

The 17° north parallel is the southern limit of the date palm in the Sahara. From the 15° north in Sudan, it follows the coast of the Red Sea and the Gulf of Aden, till it drops to 10° north to cover the northern part of Somalia. This southern line continues till it reaches the coasts of Arabia and Pakistan till the limit of Indus.

At about 33° north in the American continent, date palm plantations were newly introduced in Southern California. Seven degrees (7°) further south, less important and older introductions are found in the lower California Peninsula of Mexico. Other few, small and recent

TABLE 6
Latitude limits of date palm cultivation in the Northern Hemisphere of the Old World

To summarise, the extreme limits of date palm distribution are between 10°N (Somalia) and 39°N (Elche/Spain or Turkmenistan). Favourable areas are located between 24° and 34°N (Morocco, Algeria, Tunisia, Libya, Israel, Egypt, Iraq, Iran, etc.). In USA, date palm is found between 33° and 35°N. Because of climatic factors, the date palm will grow, but will not fruit properly outside the above defined geographical limits.

TABLE 7
Latitude limits of date palm cultivation in the southern hemisphere

(ii) Distribution according to altitude

Altitude is very important since it imposes the availability of water and the temperature limits which largely determine the distribution of date palm in the world. In fact, date palm grows and flourishes from 392 m below sea level to 1,500 m above with an altitude range of 1,892 m. Table 8 summarises this distribution based on altitude.

(iii) Number of date palms in the world

The world total number of date palms is about 100 million, distributed in 30 countries, and producing between 2.5 and 4 million tons of fruit per year.(Further details on world date production are to be found in Chapter III).

However, it is worth mentioning that accurate statistics on the number of date palms are not always available and not easy to collect. Even when some numbers are available, it is not clear to which category they belong: are they adult producing, young palms, total or both,?

If we look at the distribution region by region we find that Asia is in the first position with 60 million date palms (Saudi Arabia, Bahrain, UAE, Iran, Iraq, Kuwait, Oman, Pakistan, Turkmenistan, Yemen, etc.); while Africa is in the second position with 32.5 million date palms (Algeria, Egypt, Libya, Mali, Morocco, Mauritania, Niger, Somalia, Sudan, Chad, Tunisia, etc.).

TABLE 8
Date palm distribution in the world with regard to altitude

Mexico and the USA have 600,000 palms followed, by Europe (Spain) with 32,000 and Australia with 30,000. Table 4 illustrates this geographic distribution of date palm in different countries. Iraq is leading with 22 million palms, followed by Iran 21 million and Saudi Arabia with 12 million, Algeria 9 million, Egypt and Libya 7 million each, Pakistan and Morocco 4 million each. The remaining date growing countries have less than 1 million palms each.

Date growing countries located in the southern area of the Mediterranean Sea have approximately 35 million palms (35% of world total). Based on 200 palms/ha, they have a date palm superficies of about 175,000 ha.

Table 9 also illustrates the date palm cultivated area per country and shows that Iran has the largest superficies with 180,000 ha, followed by Iraq, 125,000 ha. Morocco has 84,500 ha while Saudi Arabia, Algeria and Egypt each have approximately 45,000 ha. In the remaining date growing countries it varies from 2,500 to 22,000 ha.

Regarding planting density, there is again a controversy about the cultural system used. Is it a modern plantation with fixed spacing (case of Israel and Tunisia), or is it the traditional planting system which is similar to a forest (case of Morocco, Pakistan, Somalia, for example). In each case, the planting density varies tremendously from 50 palms/ha (Morocco and Bahrein), up to 577 palms/ha (Somalia). Between these two extremes, there are Algeria, Libya and Tunisia with a density value of 200, 254 and 133, respectively.

Table 10 illustrates the increase in the number and percentage of the date palm culture in four North African countries. Morocco, because of the damage caused by Bayoud disease and in order to rehabilitate its plantations, is programming the production by tissue culture techniques and the plantation of approximately 2.5 million palms by the year 2007. Once implemented it will ensure an increase of 58.88%. If we look at the annual percentage increase, Morocco and Egypt are the leaders with 3.93 and 2.63, respectively. Tunisia and Algeria follow with an annual percentage increase of 1.84 and 1.10, respectively.

TABLE 9
Superficies and total number of date palms around the world

Source: Djerbi, 1995; "Options Mediterranéennes", 1996.

TABLE 10
Increase in number and percentage of date palm in Algeria, Egypt, Morocco and Tunisia

(*): Through a national programme to rehabilitate Moroccan date plantations that have been destroyed by Bayoud disease.

Source: "Options Mediterranéennes", 1996.

Looking at the areas where date palm have been harvested (ha), it is clear from Table 11 that the area harvested in the world has increased more than threefold (from 238,522 ha in 1961 to 770,795 ha in 1996) during a period of 35 years yielding an average annual increase of about 8.6 %.

The same table illustrates that during 1996, the top 10 producing countries with regard to harvested areas are in the following order: Iran (153,000 ha), Iraq (116,000 ha), Saudi Arabia (95,000 ha), Algeria (87,000 ha), Pakistan (73,915 ha), Morocco (44,400 ha), United Arab. Emirates (31,005 ha), Tunisia (29,480 ha), Oman (28,000 ha), and Egypt (26,000 ha). These 10 countries, on their own, make up approximately 88 % of the world's total harvested area.

The above-mentioned 10 countries had a different increase in harvested area for the period between 1961 and 1996. The United Arab Emirates is the leader with an increase of about 62 %, followed by Pakistan with 8.30 %, and Saudi Arabia with 4.32 %, while the remaining countries had an increase of between 2 to 3 % (Tunisia, 2.95 %, Morocco, 2.47 %, Algeria, 2.29 %; and Oman, 2.15 %). Egypt, Iran and Iraq had an increase of less than 2 %.

Table 11 also illustrates the evolution of harvested areas in other countries other than the top ten listed above. As an example, we can cite Israel with an increase of 2,286 % during the period between 1961 and 1996, with 70 ha and 1,600 ha, respectively.

TABLE 11
Area harvested in date palm growing countries (hectares) - (from 1961 till 1996)

(*) F stands for FAO estimate and C for calculated figure.
Source: FAO Trade Stat. 1997.

3. Date nutritional value

Dates are very nutritious, assimilative and energy producing.

With the present uncertainty in the world food supply and the expected increase in demand, the date palm could be a good source of food of high nutritional value. In fact, date fruit is rich in nutrients, and due to its dietetic values it has always been held in high esteem by people. Compared to other fruits and foods (apricot: 520 calories/kg; banana: 970 calories/kg; orange: 480 calories/kg; cooked rice: 1,800 calories/kg; wheat bread: 2,295 calories/kg; meat (without fat): 2,245 calories/kg, dates give more than 3,000 calories per kilogram.

Furthermore, the date palm is one of the greatest producers of food per hectare, and world date production is well over 3 million tons.

The date fruit consists of 70 % carbohydrates (mostly sugars), making it one of the most nourishing natural foods available to man. The water content is between 15 to 30 % depending on the variety and on the maturity stage of the fruit.

In most varieties, the sugar content of a date fruit is almost entirely of the inverted form (namely glucose and fructose), important for persons who cannot tolerate sucrose (cf. table 12). The invert sugar in dates is immediately absorbed by the human body without being subjected to the digestion that ordinary sugar undergoes. The flesh of dates contains 60 to 65 % sugar, about 2.5 % fibre, 2 % protein and less than 2 % each of fat, minerals, and pectin substances. Date fruits are also a good source of iron, potassium and calcium, with a very low sodium and fat content. In addition, moderate quantities of chlorine, phosphorous, copper, magnesium, silicon and sulphur are also found in the date fruit (cf. table 13).

TABLE 12
Sugar contents, in percentages, of 51 date varieties grown in the USA (Cook and Furr, 1953)

TABLE 13
Mineral constituents of the ash of date fruits

(*) The ash of dates amounts to about 2 % of cured dates (wet weight).

Date fruit is called a mine in itself because it is very rich in minerals. Its phosphorous content is similar to that found in the same quantity of apricots, pears and grapes put together.

Its high content of magnesium (±600 mg/1kg of dates) could also be very beneficial. Date consumers in Saharan areas are known to have the lowest rate of cancer diseases, a fact attributed to the magnesium found in dates.

With only 1 mg of sodium per 100 g, dates are good food for those on a low sodium diet. The iron content of 3 mg per 100g is almost a third of the Recommended Dietary Allowance for an adult male. Note that fibre, even though it is not a nutrient for humans, is of much value in a diet as an aid to digestion and evacuation. There is ample evidence that for most persons a diet fairly high in fibre is healthier than one low in fibre.

Furthermore, dates are a good source of vitamins A, B1 (thiamine), B2 (riboflavin), and B7 (nicotinic acid also called niacin). The following contents per kilogram are an average for all date varieties: vitamin A, 484 international units; B1, 0.77 milligram (mg); B2, 0.84 mg; and B7, 18.9 mg.

Protein is also of particular interest; it is variety dependent and also varies according to the stage of maturity. An average of 1.7 % of protein of the wet weight of the flesh is roughly obtained.

According to Genske and Weers, (1973), one kilogram of the flesh of ripe Deglet Noor dates contains the following: water (220g), sugar (730g; 2740 calories), proteins (22g), Fats (2g) and minerals (19g,) K 6480mg), P (630mg), Ca (590mg), Mg (580mg), Fe (30mg) and Na (10mg)), vitamin A (500 units), vitamin B1 (0.9mg), vitamin B2 (1mg) and vitamin B7 (22mg).

4. Date products

Dates are especially delicious as a fresh fruit. When used in baking they provide superb taste to the final product. Dates are also used as a component in food preparations like sweets, snacks, confectionery, baking products, institutional feeding and health foods.

Listed below is a brief summary of the main date products:

- Home-made delicatessen

* Pastry, bakery, confectionery products, and beverages
* Sandwich spreads
* Party snacks, salads and appetisers

- Semi-finished date products

* Whole pitted dates
* Macerated chips
* Date paste and date paste mixtures
* Extruded date pieces and diced dates
* Dehydrated dates, date flour (dietetic baby foods)
* Breakfast foods (dates with other dried fruits, cereals, almonds and nuts)

- Ready for use date products

* Sweets and snacks (date nut roll)
* Chocolate-coated and stuffed dates (with nuts)
* Date jams, date butter or cream
* Date preserves and cardiments, caramel products
* Date desserts (with juice, ice-cream, whipped cream, etc.)

- Derived date fruit products

* Date juice and syrup
* Liquid sugar (Saccharin as a low calorie sweetener for soft drinks), protein yeast and vinegar
* Fermentation products (wine, alcohol, organic acids, etc.)

In conclusion, dates have many strong points such as nutritional value, laxative power, exoticism, originality and a source of energy (EMER/GIK, February 1996). Their energy is in the form of invert sugars except for the Deglet Noor and Theory varieties in which about half the sugar content is cane sugar or sucrose.

In addition to the dates' high nutritive value, the date palm could play an important role in the ecology of various desert and semi-desert environments. Date palm, which is an irreplaceable tree in irrigable desert lands, provides protection to under-crops from the harshness of the climate (heat, wind and even cold weather), reduces damage caused by sand storms and wind erosion. Furthermore, with the micro climate created by date palm plantations, the cultivation of some fruit palms and annual crops will be possible.

Figure 17. Sumerian grafting:

A - Sacred date palm in Sumerian and Babylonian era. (Soussa, 1969)

B - Adam and Eve with a date palm between them (Soussa, 1969)

Figure 18. Place of origin and distribution of date fruit in the world.

Figure 19. Geographical distribution of date palm in the world