Heavy Metals and the Alternate Bearing Effect in the Date Palm (Phoenix dactylifera)

John R. Williams^1*, Avin E. Pillay²

¹Department of Chemistry, University of Hull, Cottingham Road, Hull, UK.
²Department of Chemistry, The Petroleum Institute, Abu Dhabi, UAE.

DOI: 10.4236/jep.2015.69088                

Abstract

The alternate bearing effect is when plants produce abundant crops of fruit in some years, but sparse yields in others. This review summarises recent studies that suggest a connection between the alternate bearing effect in the date palm, Phoenix dactylifera, and the presence of certain chemical elements (mostly metals) in the tree tissues. So far, there is evidence that levels of Ag, B, Ba, Ca, Cd, Cu, Fe, K, La, Mg, Mn, N, Na, Se, Tl, and Zn in the dates and leaflets are affected by the alternate bearing phenomenon. The significance of this work, therefore, emphasises the prospect of using our experimental data to overcome sparse yields, due to the alternate bearing effect, and producing more prolific growth of fruits. The potential agricultural, economic, environmental and health implications of these findings are considered.

Keywords

Alternate Bearing, Date Palm, Chemical Elements, Heavy Metals, Review

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Jonkers, H. (1979) Biennial Bearing in Apple and Pear: A Literature Survey. Scientia Horticulturae, 11, 303-317. http://dx.doi.org/10.1016/0304-4238(79)90015-3
[2]	El Mardi, M.O., Pillay, A.E., Williams, J.R., Bakheit, C.S., Hassan, S.M., Al-Hadabbi, M. and Al-Hamdi, A. (2005) Influence of Alternate Bearing on Leaf and Fruit Mineral Composition at Different Developmental Stages of Date Palm Fruits. Sultan Qaboos University Journal for Agricultural and Marine Sciences, 10, 5-12.
[3]	Nixon, R.W. and Crawford, C.L. (1942) Quality of Deglet Noor Date Fruits as Influenced by Bunch Thinning. Proceedings of the American Society for Horticultural Science, 40, 103-110.
[4]	Al Juburi, H.J. (1993) Date Palm Pruning and Fruit Thinning in the Date Palm. The Date Palm, Faculty of Agricultural Sciences, UAE University Press, Al Ain, 180-192.
[5]	El Mardi, M.O., Salama, S.B., Consolacion, E. and Al-Shabibi, M.S. (1995) Effect of Treated Sewage Water in Vegetative and Reproductive Growth of Date Palm. Communication in Soil and Plant Analysis, 26, 1895-1904. http://dx.doi.org/10.1080/00103629509369416
[6]	Mekki, M.A., Hamouda, A.H. and Al-Abri, A.S. (1998) Date Palm Pruning and Thinning in the Date Palm. Cultural Operations and Maintenance. Modern Color Press, Muscat, 335-338.
[7]	Batjar, L.P. and Westwood, M.N. (1958) Seasonal Trends of Several Nutrient Elements in Leaves of Alberta Peach. Proceedings of the American Society for Horticultural Science, 65, 116-126.
[8]	Nixon, R.W. (1935) Metaxenia in Dates. Proceedings of the American Society for Horticultural Science, 32, 221-226.
[9]	Nixon, R.W. (1936) Metaxenia and Interspecific Pollination in Phoenix dactylifera. Proceedings of the American Society for Horticultural Science, 33, 21-26.
[10]	Nixon, R.W. (1940) Fruit Shrivel of Halawy Date in Relation to Amount and Method of Bunch Thinning. Proceedings of the American Society for Horticultural Science, 41, 85-92.
[11]	Swingle, W.T. (1925) Pruning the Date Palm. Date Growers Institute Report, 2, 12-13.
[12]	Mathes, F. and Bliss, D.E. (1942) The Relationship of Leaf Area to Alternate Bearing in the Deglet Noor Palm. Date Growers Institute Report, 19, 3-7.
[13]	Al Khateeb, A.A., Al-Tahir, O.A. and Al-Ghamdi, A. (1993) Thinning Stage Effects on Fruit Size, Yield and Quality of Date Palm (Phoenix dactylifera L.) cv “Khalas”. Proceedings of the Third Symposium on the Date Palm, Al-Hassa, 17-20 January 1993, 231-237.
[14]	Patrick, J.W. (1988) Control of Assimilate Partitioning in Relation to Crop Productivity. Horticultural Science, 23, 33-40.
[15]	Patrick, J.W. (1991) Control of Phloem Transport to the Short Distance Transfer in Sink Region: An Overview. In: Bonnemain, J.L., Delrot, S., Lucas, W.L. and Dainty, J., Eds., Recent Advances in Phloem Transport and Assimilate Compartmentation, Ouest Editions, Nantes, 167-177.
[16]	Goren, R. and Monselise, S.P. (1971) Effect of Ripening on Field of Low Bearing Orange Trees. Journal of Horticultural Science, 46, 435-441.
[17]	Faust, M. (1989) Physiology of Temperate Zone Fruit Trees. Wiley Intersciences, New York, 106-227.
[18]	El Mardi, M.O., Salama, S.B., Consolacion, E.C. and Al-Solomi, M. (1998) Effect of Treated Sewage Water on the Concentration of Certain Nutrient Elements in Date Palm Leaves and Fruits. Communications in Soil Science and Plant Analysis, 29, 763-776. http://dx.doi.org/10.1080/00103629809369983
[19]	Nixon, R.W. and Wedding, R.T. (1956) Age of Date Leaves in Relation to Photosynthesis. Proceedings of the American Society for Horticultural Science, 67, 263-269.
[20]	Hassan, F.A., Badr, M.S., Algadri, M.T. and Samarmad, I.N. (1984) Effect of Pruning Date Palms (Phoenix dactylifera L.) on Fruit Quality and Chemical Characteristics. Date Palm Journal, 3, 23-62.
[21]	Mustafa, A.A. (1993) Effect of Fruit Thinning on Yield and Fruit Quality of “Seeway” Date Palm under Al-Fayoum Governorate Conditions. Proceedings of the Third Symposium on the Date Palm, Al-Hassa, 17-20 January 1993, 239-245.
[22]	El Mardi, M.O., Esechie, H., Al-Kharousi, I.M. and Abdelbasit, K.M. (2002) Effect of Pollination Method on Changes in Physical and Chemical Characteristics of Date Fruit During Development. Agricultural Sciences, 7, 21-27.
[23]	Radojevic, M. and Bashkin, V.N. (2006) Practical Environmental Analysis. RSC Publishing, Cambridge.
[24]	Harris, D.C. (1999) Quantitative Chemical Analysis. Freeman, New York.
[25]	Pillay, A.E., Williams, J.R., Hassan, S.M., El Mardi, M.O. and Al-Hamdi, A. (2002) Monitoring of Cadmium in “on” and “off” Date Palms. Environment International, 28, 273-276. http://dx.doi.org/10.1016/S0160-4120(02)00034-X
[26]	Williams, J.R., Pillay, A.E. and Yaghi, B. (2008) Date Palm Leaflets: Bioindicators of Total Mercury in Soil and Assessment of the Potential for Biomagnification of Total Mercury along a Food Chain. Research Journal of Chemistry and Environment, 12, 27-29.
[27]	Jones Jr., J.B. (1998) Plant Nutrition Manual. CRC Press, New York.
[28]	Shaw, A.J. (1989) Heavy Metal Tolerance in Plants: Evolutionary Aspects. CRC Press, Boca Raton.
[29]	Williams, J.R., Pillay, A.E., El Mardi, M.O., Al-Lawati, S.M.H. and Al-Hamdi, A. (2005) Levels of Selected Metals in the Fard Cultivar (Date Palm). Journal of Arid Environments, 60, 211-225. http://dx.doi.org/10.1016/j.jaridenv.2004.04.005
[30]	Pillay, A.E., Williams, J.R., Hassan, S.M., El Mardi, M.O. and Al-Hamdi, A. (2005) Boron and the Alternate-Bearing Phenomenon in the Date Palm (Phoenix dactylifera). Journal of Arid Environments, 62, 199-207. http://dx.doi.org/10.1016/j.jaridenv.2004.11.007
[31]	Baird, C. (1999) Environmental Chemistry. Freeman, New York.
[32]	El Mardi, M.O., Pillay, A.E., Williams, J.R., Bakheit, C.S., Hassan, S.M., Al-Hadabbi, M. and Al-Hamdi, A. (2005) Influence of Alternate Bearing on Leaf and Fruit Mineral Composition at Different Developmental Stages of Date Palm Fruits. Sultan Qaboos University Journal for Agricultural and Marine Sciences, 10, 5-12.
[33]	Pillay, A.E., Williams, J.R., El Mardi, M.O., Al-Lawati, S.M.H., Al-Hadabbi, M.H. and Al-Hamdi, A. (2003) Risk Assessment of Chromium and Arsenic in Date Palm Leaves Used as Livestock Feed. Environment International, 29, 541-545. http://dx.doi.org/10.1016/S0160-4120(03)00011-4
[34]	Williams, J.R. and Pillay, A.E. (2009) Monitoring Nickel Uptake in Date Palms from Nickel-Contaminated Soil. Research Journal of Chemistry and Environment, 13, 5-9.
[35]	Pulford, I. and Flowers, H. (2006) Environmental Chemistry at a Glance. Blackwell, Oxford.