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Common names
Date, date palm [English]; palmera datilera, palma datilera, támara, fénix, datilero [Spanish]; dattier, palmier dattier [French]; tamareira, datileira [Portuguese]; dadelpalm [Dutch]; Echte Dattelpalme [German]; pohon kurma [Indonesian]; palma da datteri [Italian]; kurma [Javanese]; Geed Timir [Somali]; Palmerang datilero [Tagalog]; ఖర్జూరం [Telugu]; hurma [Turkish]; نخلة التمر [Arabic]; খেজুর [Bengali]; Χουρμαδιά [Greek]; ખજૂર [Gujarati]; खजूर [Hindi]; תמר מצוי [Hebrew]; ナツメヤシ [Japanese]; 대추야자 [Korean]; खजूर [Marathi]; Zōyacapolcuahuitl [Nahuatl]; خرما [Persian]; Финиковая пальма, Финик пальчатый [Russian]; อินทผาลัม, อินทผลัม [Thai]; کھجور [Urdu]; chà là [Vietnamese]; 海枣 [Chinese]
- Cull dates, culled dates, date waste, wasted dates, whole dates, immature dates
- Pitted dates, stoned dates
- Date press cake
Species
Feed categories
Related feed(s)
Description
Dates, the fruits of the date palm tree (Phoenix dactylifera L.), are a major staple food in arid areas of North Africa and the Middle East, and the date crop plays a central role in the economy and social life of these regions (Janick et al., 2008; Botes et al., 2002; El-Deek et al., 2010). There are more than 3000 date varieties in the world. Iran, Irak, Morocco and Tunisia have the most diversified germplasm (Zaid et al., 2002; Abdelmajid, 2005). While date palms are primarily cultivated for food, some local varieties are traditionally grown for animal consumption (Williams, 1978).
The date palm is an evergreen palm tree that can reach 15-40 m in height. Its fasciculated root system can grow to a depth of 6 m (Zaid et al., 2002). The stem, or stipe, is cylindrical, straight, up to 1-1.1 m in diameter. The date palm bears 100-120 large fronds, 4-7 m long. Phoenix dactylifera is a dioecious species with male and female plants. A female tree bears about 12 inflorescences per year. These spikelike clusters of up to 10,000 flowers have a central rachis and 50-100 spikelets (Zaid et al., 2002; Ecocrop, 2011). Date palm trees begin fruiting within 2 to 4 years and reach full production at 5-8 years (Ecocrop, 2011). An average well-managed palm can produce about 60-70 kg of fresh dates per year but yields up to 200 kg/year can be obtained (Ecocrop, 2011; Peyron, 2000). The date fruit is an oblong, one-seeded berry, with a fleshy and sweet pericarp. Dates vary greatly in size (18 to 110 mm long), weight (2-60 g), colour (yellow to black) and taste. The date seed (also called pit, stone or kernel) is hardcoated, oblong and weighs 0.5 to 4g (Zaid et al., 2002).
The date palm industry produces fresh and dried dates, whole dates and pitted (stoned) dates, date paste, date syrup and date wine. Date by-products include cull dates, immature dates, date pedicels, date seeds, date presscake and date molasses. All these by-products are used to feed animals. This datasheet deals with cull dates and other fleshy by-products. The other by-products are described in the datasheets Date seeds, Date leaves and pedicels and Date molasses. Phoenix dactylifera is also a useful agroforestry species with other uses than date production: the trunks are tapped for a sap that is made into palm wine and the leaves are harvested for thatch, fiber, basketry and fodder (Ecocrop, 2011).
Distribution
In 2009, 7.52 million tons of date palm fruits were produced worldwide. Date palm trees were planted in 1.15 million ha and the average yield was about 6.52 t/ha (FAO, 2011). The main producers were Egypt, Iran, Saudi Arabia, the United Arab Emirates, Pakistan, Algeria, Iraq, Sudan and Oman (FAO, 2011). Arab countries possess 70% of the world date palms (El-Juhany, 2010). Most of the production is consumed locally and only 10% were exported in 2007.
Date palm is one of the oldest domesticated fruit crops (since 4000 BC in Ancient Egypt), and one of the most important growing in desert areas (Ramawat, 2010). Date palm trees are widely spread in arid and semi-arid areas within 10° and 39° in the Northern Hemisphere, the optimal latitude being between 24 and 34°N in the Old World, and between 33 and 35°N in the West Coast of the USA (Zaid et al., 2002). It has also been introduced into other countries such as Pakistan, Australia, Mexico, South America and South Africa (Janick et al., 2008; Chao et al., 2007).
Date palm grows well in areas with long and hot summers, no or low rainfall, and very low relative humidity levels during the ripening period (Zaid et al., 2002). Date palm can be grown from sea level up to an altitude of 1500 m (Ecocrop, 2011). The optimal temperature for growth is about 32°C, but the date palm can withstand up to 56°C under irrigation (Zaid et al., 2002). A date palm tree requires 0.21-0.56 m3 (0.72 m3; Rolland, 1894 cited by Zaid et al., 2002) of water per day. If ground water is inadequate, irrigation is necessary (Ecocrop, 2011; Peyron, 2000). Date palm is tolerant of windy conditions and can bear strong, hot, dusty and dry winds. It is thus used as wind breaks for more sensitive plantations. Date palm has also some tolerance to soil salinity but cannot be considered a true halophyte since it grows better on sweet soils than on salty soils (Zaid et al., 2002).
Processes
The main by-products of date packing are cull dates, date seeds and date pedicels (Arbouche et al., 2008; Barreveld, 1993). Date processing also yields seeds, presscakes (also called date pulp) (Barreveld, 1993). Only cull dates and date presscake are considered below. The other by-products are fully described in Date seeds and other date by-products.
Cull dates
Cull dates are fruits that are too hard, too small, blemished, of poor appearance, infested or containing foreign matter (Barreveld, 1993). Culled date are also fruits that have suffered from drought and dates unfertilized due to lack of pollen (Chehma et al., 2001). About 20-25 % of the production is fed to livestock (Williams, 1978; El-Deek et al., 2010; Chehma et al., 2001).
They can be fed whole to cattle, camels, sheep and goats. However, the stone is undigested and it is recommended to grind the dates before feeding, provided that the cost of processing is outweighed by the gain in feed value. Unless they are very hard and dry, dates tend to clog the sieves of the hammermills and it is necessary to mix them with a dry material such as barley, maize or soybean meal. The optimal inclusion rate of dates in the mix is about 30% which gives good pellets, with the additional benefit that dates take the place of molasses as a lubricant and binder in the process of pelletizing. Less than 20% dates in the mix results in pellets of poor quality that require the addition of molasses. Grinding whole dates is also an energy-consuming operation because dates are dry and their pits are very hard (Barreveld, 1993).
Pitting cull dates can be done by soaking dates in water and mixing them until the pits are removed. The resulting flesh (date mash) is then mixed with flaked barley and dried on a rotary drier. The date mash can also be used as binding agent in pelletizing and can replace molasses: no more than 13-16 kg date mash (i.e. 5-6 kg date flesh) should be added to 100 kg of concentrate if the resulting product has to be stored. The product should then have less than 12-15% moisture (Barreveld, 1993).
Silage can also be made from chopped date palm stems or fronds (45%) mixed with cull dates (35%), wheat bran and urea (Khorchani et al., 2004).
Date press cake
When dates undergo extraction for syrup or alcohol production, the extraction yields a by-product (press cake) which is made of exhausted date flesh and residual sugars, with or without pits. Press cake is a high moisture product that does not store easily and may become a disposal problem (Barreveld, 1993).
Environmental impact
Soil salinity tolerance
Date palm has the highest salinity tolerance among fruit trees. The low soil requirements and high adaptability of date palm represent another advantage in salt-affected environments (Qadir et al., 2008).
Other environmental services
Date palm provides protection (shade and shelter) to under-crops (fruit trees or annual crops) from the harshness of the climate (heat, wind and cold weather). Date palm also prevents soil degradation and desertification (El-Juhany, 2010; Sawaya, 2000).
Palm trees are a keystone species in oasis agriculture. They ensure an optimal use of space, biodiversity, water resources and the work force (Koohafkan, 2002; Sawaya, 2000). Date palm is a valuable crop for establishing a sustainable system of subsistence agriculture, thus helping populations to settle in rural areas (Sawaya, 2000).
By-products
The by-products of date production have always been recycled by farmers and local populations, and have been considered as "an eloquent example of integrated sustainable use of renewable material resources" (El-Mously, 2001). There is a long tradition of using cull dates and date pits to feed animals, and the crop residues serve as raw materials to create household items, furniture and building materials (El-Mously, 2001).
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